Bashir Lwaleed

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Papers by Bashir Lwaleed

Diluted honey inhibits biofilm formation: potential application in urinary catheter management?

by Bashir Lwaleed and Brian Birch

Journal of clinical pathology, Jan 26, 2016

Biofilms are ubiquitous and when mature have a complex structure of microcolonies in an extracell... more Biofilms are ubiquitous and when mature have a complex structure of microcolonies in an extracellular polysaccharide and extracellular DNA matrix. Indwelling medical devices harbour biofilms which have been shown to cause infections and act as reservoirs for pathogens. Urinary catheters are often in place for considerable periods of time and are susceptible to both encrustation and biofilm formation. Strategies for minimising biofilm occurrence underpin an active research area in biomedicine. Manuka honey has, inter alia, well-established antibacterial properties. This study aims to assess the influence of honey on early biofilm formation in an established in vitro model. An established model of early biofilm formation using static bacterial cultures in vinyl 96-well plates was used to grow Escherichia coli, strain ATC 25922 and Proteus mirabilis, strain 7002. Planktonic cells were removed and the residual biofilm was stained with crystal violet, which were subsequently eluted and q...

Back to basics: histological, microbiological and biochemical sampling in wound care

Journal of Wound Care, Nov 14, 2013

6 5 0 j o u r n a l o f wo u n d c a r e v o l 2 2 , n o 1 1 , n o v e m b e r 2 0 1 3 basics © 2... more

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Quantification of seminal thrombomodulin

Quantitation of thrombin activatable fibrinolysis inhibitor (TAFI) in human semen

by Bashir Lwaleed and Brian Birch

Artemisinins as potential anticancer agents: uptake detection in erythrocytes using Fourier transform infrared spectroscopy and cytotoxicity against bladder cancer cells

by Bashir Lwaleed and Brian Birch

Journal of Clinical Pathology, 2016

Semisynthetic derivatives of the antimalarial drug artemisinin may also possess anticancer proper... more Semisynthetic derivatives of the antimalarial drug artemisinin may also possess anticancer properties. The ability to detect artemisinin uptake and distribution in cells would facilitate live cell imaging without labelling. This study describes mid-range infrared absorption spectra for three artemisinin variants and attempts to detect their presence in a simple cell model (erythrocytes). Cytotoxicity assays assess potential anticancer properties against bladder cancer cells. Mid-range Fourier transform infrared spectra were obtained from dry preparations of dihydroartemisinin (DHA), artesunate (ART) and artemether (ARTE). Erythrocytes were prepared from normal blood and incubated for 30 min at 37°C with the three artemisinin derivatives. Cytospin preparations were prepared on aluminium foil for spectroscopy. Potential for growth inhibition in the RT112 bladder carcinoma cell line was assessed by the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide residual viable biomass method. Spectra were obtained from the three native compounds. Repeat scans after 8 weeks showed ART and ARTE to be stable, stored under manufacturer&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;#39;s recommendations. DHA exhibited marked changes over the same period. It was possible by subtraction to detect DHA in cytospins, but not ART or ARTE. The fit between the subtraction spectrum and that of the native compound was &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;gt;80%. DHA and ART showed strong cytotoxic potential against RT112 cells. The artemisinin derivatives tested exhibit unique mid-range infrared absorption spectra which can be used to monitor degradation and, for DHA, can be detected by subtraction in loaded erythrocytes rendering future imaging studies feasible. Its cytotoxic efficacy against RT112 cells suggests bladder cancer as a possible target disease.

The direct effect of nuclear pores on nuclear chemotherapeutic concentration in multi-drug resistant bladder cancer: the nuclear sparing phenomenon

by Bashir Lwaleed and Brian Birch

Multidrug resistance commonly limits effectiveness in treating malignancy with chemotherapy. Mult... more Multidrug resistance commonly limits effectiveness in treating malignancy with chemotherapy. Multidrug resistance has classically been described as a cell membrane phenomenon. Multidrug resistant cells are known to specifically exclude chemotherapy from the nucleus, resulting in lower nuclear concentrations than in the cytoplasm. This phenomenon is known as nuclear sparing and little is known of its etiology. We hypothesized that a component of the nuclear membrane, the nuclear pore, is responsible for this phenomenon. In this in vitro study we used the drug sensitive urothelial cancer cell line Massachusetts General Hospital urothelial 1 sensitive and its multidrug resistant subline Massachusetts General Hospital urothelial 1 resistant. After quantitative assessment of nuclear pores resistant and sensitive cells were fused using polyethylene glycol and laser scanning confocal microscopy was used to identify if drug resistant and sensitive nuclei can coexist within the same cell. The effect of inhibiting nuclear pore function using the specific pore inhibitor, wheat germ agglutinin, was assessed in whole cells using confocal microscopy and cytotoxicity assay as well as in isolated nuclei. Nuclear pores appeared more numerous in multidrug resistance cells. Cell fusion experiments showed that multidrug resistance and sensitive nuclei could coexist with the same cell milieu. Wheat germ agglutinin reversed multidrug resistance in whole cells and isolated nuclei. Multidrug resistance is a complex phenomenon occurring at many cellular levels, of which all may be potential therapeutic targets. The nuclear pore is involved in this process, which is to our knowledge a previously undescribed phenomenon. These experiments suggest that it may act to export drug from the nucleus, which is a process inhibited by wheat germ agglutinin.

Book review. Outcome assessment in cancer: measures, methods and applications, edited by Joseph Lipscomb, Carolyn C. Gotay, and Claire Snyder

Quantitation of thrombin activated fibrinolysis inhibitor (TAFI) in human semen

by Bashir Lwaleed and Brian Birch

Seminal factor VII and VIIa: the ultimate evidence on the presence of the tissue factor dependent pathway in human semen

Seminal thrombin-activatable fibrinolysis inhibitor: a regulator of liquefaction

Blood Coagulation and Fibrinolysis, Jul 1, 2007

Several active components of the haemostatic system have been identified in human semen. Here we ... more Several active components of the haemostatic system have been identified in human semen. Here we investigated the presence of thrombin-activatable fibrinolysis inhibitor (TAFI) in seminal plasma. Using an enzyme-linked immunosorbent assay, TAFI levels were measured in 36 semen specimens obtained from subfertile, normally fertile, fertile sperm donor and vasectomized individuals. TAFI was detectable in human semen. Its levels were highest in vasectomized individuals compared with the other groups, including a pooled normal semen parameter stratification group (by World Health Organization criteria). This elevation in the vasectomy group was found to be statistically significant in comparison with the normally fertile (P &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt; 0.01) and the pooled normal semen parameter groups (P &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt; 0.05). Seminal TAFI levels showed a significant positive correlation with total sperm count and sperm density. In contrast, a negative association was observed with semen volume, days of sexual abstinence and liquefaction time. The highly motile sperm group showed low TAFI levels. Our results establish the presence of TAFI in seminal plasma with a probable role in the protection of the seminal clot against lysis. It also suggests a downstream (post-testicular) source for its production. This reinforces the involvement of the conventional haemostatic system in the coagulation and liquefaction properties of human semen.

Seminal Hemostatic Factors: Then and Now

Seminars in Thrombosis and Hemostasis, Mar 1, 2007

Human semen spontaneously coagulates and subsequently liquefies following ejaculation. The exact ... more Human semen spontaneously coagulates and subsequently liquefies following ejaculation. The exact reasons for this phenomenon are not entirely understood. Research has resulted in the discovery of several seminal proteins that are already known from another major domain of human physiology (i.e., blood coagulation and fibrinolysis). Some believe that regulation of seminal coagulation and fibrinolytic liquefaction may bear analogies to the well-described pathways operational in blood. We here attempt to summarize the subject, revisiting earlier findings and covering the more recent and extensive data on hemostatically functional seminal proteins, including the findings of our own group. Evidence for the existence of each key hemostatic factor in semen is presented along with any correlation with indices of male fertility. Several probably possess alternative functions including anti-inflammatory action, aiding sperm capacitation and classic hemostasis following intercourse-induced bleeding. Established mechanisms such as the high molecular weight seminal vesicle system are also considered as potentially interacting with conventional hemostatic pathways to regulate seminal coagulation and liquefaction. Although our grasp of this subject continues to evolve, there still remain many unanswered questions. A more complete understanding may one day prove useful in designing technologies for improved diagnostics in male infertility and potentially aiding assisted human reproductive therapies.

Seminal prostasomes inhibit the angiogenesis activity of rat aortic rings

Prostate Cancer Prostatic Dis, 2006

Prostasomes are organelles secreted by prostatic epithelial cells, and are believed to have a rol... more Prostasomes are organelles secreted by prostatic epithelial cells, and are believed to have a role in fertility and prostatic disease. They are known to influence sperm motility and the acrosome reaction, and are thought to have a role in cell transformation, immunosuppression, proliferation, facilitation of local invasion, and angiogenesis. Previously, we have demonstrated the inhibitory effect of prostasomes derived from human semen on angiogenesis using HUVEC cells grown on matrigel. In this study, we use the rat aortic ring assay system, arguably a closer reflection of the in vivo situation. Quantification was by a spectrophotometric method, and underlying mechanisms assessed. Prostasomes demonstrated a clear inhibition of angiogenesis, and this effect persisted after heat treatment of prostasomes to denature protein. This fits with other known effects of prostasomes known to be due to the membrane lipid component, which is unusually high in sphingomyelin and cholesterol.

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Inhibition of angiogenesis by prostasomes

Honey: a potential intravesical therapeutic

by Bashir Lwaleed and Brian Birch

Role of Seminal Hemostatic Factors and Semenogelins in the Reproductive Tract

Semin Thromb Hemostasis, 2007

Homeostasis of Hemostasis: The Role of Endothelium

by Bashir Lwaleed and Rashid Kazmi

Seminars in Thrombosis and Hemostasis, 2015

Forming an interface with virtually every other organ, endothelium has a strategic role in modula... more Forming an interface with virtually every other organ, endothelium has a strategic role in modulating vascular homeostasis. While its miscellany of functions includes regulation of vasomotor tone, promotion, and prevention of vascular growth, and modulation of inflammatory and hemostatic processes, it functions critically in maintaining the balance of hemostasis in health. Whereas endothelium has been recognized to influence all stages of hemostasis, new evidence suggests it to have a primary role for thrombin generation. Endothelial dysfunction is being increasingly appreciated in several pathological states and particularly, by virtue of its critical role in hemostasis, in causing thrombosis in a multitude of diseases.

Inflammation, Endothelial Dysfunction, and Thromboembolism

by Bashir Lwaleed and Rashid Kazmi

Seminars in thrombosis and hemostasis, 2015

The Activation of Complement and Its Role in the Pathogenesis of Thromboembolism

by Bashir Lwaleed and Rashid Kazmi

Seminars in Thrombosis and Hemostasis, 2015

It is well established that inflammation and thrombosis are intricately linked processes, and the... more It is well established that inflammation and thrombosis are intricately linked processes, and there is increasing evidence of the importance of their roles in activated complement in the pathogenesis of thromboembolism. The two systems are activated by similar stimuli simultaneously and interact, either directly or through biochemical mediators, to protect the host from microbial invasion. Diseases characterized by complement hyperactivity such as paroxysmal nocturnal hemoglobinuria and atypical hemolytic uremic syndrome have high rates of thrombosis. This review describes how disease processes where there is excessive complement activation leads to thrombosis, and the specific interactions between the complement and coagulation systems that lead to pathological thrombus formation.

Honey promotes angiogenic activity in the rat aortic ring assay

Journal of Wound Care

To investigate possible effects of honey on angiogenesis, using in vitro analogues of angiogenesi... more To investigate possible effects of honey on angiogenesis, using in vitro analogues of angiogenesis and an endothelial proliferation assay. Using an in vitro rat aortic ring assay we compared pseudotubule formation by medicinal honey (Activon), supermarket honey (Rowse) and a honey-based ointment (Mesitran), with that of artificial honey (70% w/w sugar glucose/fructose). Pseudotubules were analysed using TCS Cellworks AngioSys software. The Angiokit sytem was used to validate the results. Using the MTT [3-(4,5-Dimethylthiazol-2-yl)-2,5-Diphenyltetrazolium. Bromide] assay, toxicity was also assessed on human umbilical vein endothelial cells (HUVEC) directly adherent to plastic. All honey preparations stimulated pseudotubule formation, maximal at around 0.2% honey. Medicinal honeys were more active than Rowse. The effect was not attributable to the sugar content. Among the honeys tested, the Manuka-based Activon preparation reduced residual viable biomass compared with a sugar control ...

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Tissue factor and tissue factor pathway inhibitor in women with a past history of preeclampsia: implication for a hypercoagulable state postpregnancy!

by Bashir Lwaleed and Brian Birch

Blood coagulation & fibrinolysis: an international journal in haemostasis and thrombosis

Preeclampsia (P-EC) is a multisystem disorder of pregnancy whose cause and pathogenesis remain po... more Preeclampsia (P-EC) is a multisystem disorder of pregnancy whose cause and pathogenesis remain poorly understood. However, abnormal haemostasis and endothelial dysfunction are thought to be implicated. Women with a past medical history of P-EC have a baseline hypercoagulable state postpregnancy. The aim of this study is to examine the relationship between tissue factor (TF) and TF pathway inhibitor (TFPI) in women who have had P-EC within the last 3 years (more than 6 months postpartum) and their normal counterparts. Blood specimens were collected from women known to have had P-EC within the last 3 years (n = 26) and aged-matched healthy women without past history of P-EC in previous pregnancy (n = 26). Plasma TF and TFPI levels were measured using ELISAs. Women who have had P-EC showed increased TF levels compared with their normal counterparts, whereas TFPI levels were reduced. Neither parameter differed significantly when the groups were tested against each other. Interestingly, ...

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