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Biomedical subjects

B A Lwaleed

Publications and source records attributed to B A Lwaleed.

At least 19 recordsLinked to original sources
PubMed2006

Meglumine Eicosapentaenoic acid (MeEPA) a new soluble omega-3 fatty acid formulation: in vitro bladder cancer cytotoxicity tests in combination with epirubicin and mitomycin.

OBJECTIVE: To determine if Meglumine-Eicosapentaenoic Acid (MeEPA) acts synergistically with epirubicin and mitomycin to enhance cytotoxicity towards bladder cancer cell lines in vitro. MATERIALS AND METHODS: Bladder cancer cells were exposed to MeEPA in combination with epirubicin or mitomycin. Residual viable cell biomass was estimated with the methyl-thiazoldiphenyl tetrazolium (MTT) assay following drug exposure. Drug interaction was analysed using median effect analysis to determine levels of synergism. RESULTS: Most combinations of MeEPA with both epirubicin and mitomycin showed a high-level of synergism. At high doses, drug precipitation adversely affected MTT assay analysis suggesting antagonism of action. However, the predominant pattern was of synergism for most dose combinations tested. CONCLUSION: Bladder cancer treated by endoscopic resection alone is subject to high recurrence rates. Post-operative intravesical instillation of epirubicin and mitomycin can halve recurrence rates, but there is no evidence that disease progression to invasive bladder cancer is altered. Thus, optimisation of current treatment strategies is required. The anti-tumour activity of fatty acids is well established and MeEPA is a new, soluble formulation with the potential to enhance intravesical drug efficacy.

Antibiotics, Antineoplastic↗
PubMed2006

Seminal prostasomes inhibit the angiogenesis activity of rat aortic rings.

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.

Animals↗
PubMed2006

Furosemide reverses multidrug resistance status in bladder cancer cells in vitro.

BACKGROUND: Multidrug resistance (MDR) has a potentially serious influence on cancer treatment and should be taken into consideration in the design and application of therapeutic regimens. It is mediated through the activity of cellular pumps. AIM: To investigate whether furosemide, itself a pump-blocker, reverses MDR in an in vitro model. MATERIALS AND METHODS: An MDR bladder cancer cell line (MGH-u 1R) and its parental (drug sensitive) clone were exposed to epirubicin and furosemide, with the concentration of one drug fixed and that of the other serially diluted in a 96-well plate format. Both drugs formed the variable component in separate experiments. After a 1-h exposure, the cells were washed and replenished with fresh medium. To examine the toxicity of epirubicin and furosemide separately and in combination, monotetrazolium-based assays were carried out. Intracellular epirubicin distribution was assessed by confocal microscopy as a second index of resistance status after in vitro exposure. RESULTS: MGH-u 1R cells incubated with furosemide showed distribution of drug similar to that in the parental cells (MGH-u 1 sensitive). Controls (without furosemide) continued to show a resistant pattern of fluorescence. In cytotoxicity assays furosemide appeared substantially non-toxic. Resistant cells in the toxicity titration experiments showed increased resistance to levels of furosemide over 500 mug/ml. Parental cells were made only marginally more sensitive against increased background toxicity. CONCLUSION: Furosemide is effective in reversing MDR status in bladder cancer cell lines in vitro. It may also have an increment of intrinsic cytotoxicity, but only at higher concentrations. We propose a potential for further investigation of furosemide as an adjunct to chemotherapy for superficial bladder cancer.

Antibiotics, Antineoplastic↗
PubMed2006

Can lycopene be delivered into semen via prostasomes? In vitro incorporation and retention studies.

Lycopene (C(40) H(56)) is a highly lipophilic antioxidant found in human semen in nanomolar concentrations. It has been shown to be one of the most potent carotenoid antioxidant in various human studies. Prostasomes are organelles secreted by glandular prostatic epithelial cells and are known to play an important role in fertility and prostate cancer. They are also known to possess antioxidant activity and aid the functioning of sperm. We studied the ability of these vesicles to adsorb and retain lycopene into their rich lipid environment in vitro. High-performance liquid chromatography analysis confirmed micrograms of lycopene per milligram of prostasomal protein. In view of the prostasomes' lipid-rich nature it is highly likely that these organelles act as delivery vehicles for this highly lipophilic antioxidant substance into human semen.

Adsorption↗
PubMed2005

In vitro inhibition of angiogenesis by prostasomes.

Prostasomes are biologically active organelles that are secreted by human prostate epithelial cells, and it is believed that they have a role in prostatic disease. We studied the effect of prostasomes on the human umbilical vein endothelial cell (HUVEC)/Matrigel model of angiogenesis, and the association of labelled prostasomes with HUVECs. The growth inhibitory effect of prostasomes on HUVECs was assayed by spectrophotometric measurement of residual biomass. Preparations of HUVECs on a Matrigel base were exposed to prostasomes, and the development of capillary-like networks was quantified. Prostasomes were labelled with PKH-26, and cultured with HUVECs. Prostasomes were not shown to have a significant effect on HUVEC survival. Angiogenesis assays showed inhibition. The PKH-26-labelled particles were shown to have adhered to the HUVECs. This study adds the inhibition of an in vitro correlate of angiogenesis to the known actions of prostasomes.

Cell Culture Techniques↗
PubMed2002

The clinical value of measuring tissue factor activity in patients with cancer.

The association between cancer and thromboembolic disease is well known. This relationship is complex and in many, perhaps most, malignant diseases acts through multiple pathways. Increased tissue factor expression by endothelial cells, monocytes or macrophages has been implicated as one of these pathways. As well as being found in the circulating blood, tissue factor is also found in urine in a lipid-associated form. Although urinary tissue factor might be independent from that found in the circulation, its levels may reflect the status of peripheral blood monocyte activation. Thus, measurements of monocyte and/or urinary tissue factor may be of clinical significance, particularly in cancer, where levels could be valuable for diagnosis and monitoring progression.

Humans↗
PubMed2001

The biology and tumour-related properties of monocyte tissue factor.

Tissue factor (TF, coagulation factor III, CD142) is not only the main physiological initiator of normal blood coagulation, but is also important in the natural history of solid malignancies in that it potentiates metastasis and angiogenesis and mediates outside-in signalling. TF is expressed constitutively by many tissues which are not in contact with blood and by other cells upon injury or activation; the latter include endothelial cells, tissue macrophages, and peripheral blood monocytes. It can exist encrypted and unavailable functionally in the plasma membrane and the appearance of functional TF may be due to synthesis and/or de-encryption. Inflammatory cells often express TF and act to induce its production or de-encryption by other cells locally and, apparently, at remote sites. Inappropriate expression of TF by endothelial cells, macrophages or monocytes is thought to be an important trigger of coagulation in various pathological conditions. Several studies have shown that measurements of monocyte TF (mTF) may provide clinically significant information, particularly in patients with malignant and inflammatory diseases.

Biomarkers, Tumor↗
PubMed2000

Urinary tissue factor levels in patients with bladder and prostate cancer.

AIMS: Coagulation activation is a recognized complication of cancer in which increased tissue factor (TF) is implicated. TF can be detected in urine (uTF). This study assesses uTF levels in benign and malignant urological disease and correlates the results with conventional markers of tumour progression. METHODS: Using a simple and reproducible kinetic chromogenic assay, we determined uTF levels in controls (normal volunteers (n = 57) and patients with renal stones (n = 30)), benign and malignant bladder (n = 75) or prostate (n = 106) disease and in patients with or without recurrent bladder cancer (n=30). Each benign disease group was stratified as inflammatory (cystitis or prostatitis) or non-inflammatory (negative cystoscopy following haematuria or benign prostatic hypertrophy). RESULTS: The controls and the benign non-inflammatory results were indistinguishable. The malignant and inflammatory groups showed raised uTF levels over controls (P<0.001 bladder and P<0.01 prostate). The difference between malignant and benign inflammatory disease was only significant for the bladder group. uTF levels were significantly related to histological tumour grading, prostate serum specific antigen, static bone scan images and recurrence status. CONCLUSIONS: uTF levels can distinguish, statistically but not without overlap, patients with malignancy from normal controls and benign non-inflammatory conditions. Discrimination between inflammatory and malignant disease has only been demonstrated in the bladder. uTF levels showed a significant association with markers of tumour progression or metastasis and may be useful in predicting bladder tumour recurrence.

Adult↗
PubMed2000

Tissue factor expression and multidrug resistance in cancer: two aspects of a common cellular response to a hostile milieu.

Tissue factor (TF) is the main physiological initiator of blood coagulation and its activation or de-encryption within plasma membranes is important for trapping, extravasation and angiogenesis in the development and spread of solid malignancies. Multidrug resistance is also an adaptive response in malignant (and normal) cells. It is often mediated by the over-expression of the P-glycoprotein (P-gP) efflux pump. Both TF and P-gP tend to be expressed together, perhaps as part of a coherent 'crisis management' response of cells to environmental change or challenge. An associated feature in such a response appears to be the reversal of normal phospholipid charge asymmetry in the plasma membrane bilayer. Responses to environmental stimuli affect function in normal and malignant tissue. Uniting the study of TF expression or de-encryption and MDR-1 phenotype would be biologically enlightening and might ultimately influence clinical cancer management and the control of thrombotic problems associated with treatment.

ATP Binding Cassette Transporter, Subfamily B, Mem↗
PubMed2000

Monocyte tissue factor levels in cancer patients.

OBJECTIVE: The association between cancer and thromboembolic disease has been known for over a century. Increased tissue factor expression by endothelial cells, monocytes or macrophages is implicated. Thus, monocyte tissue factor measurements may reflect disease presence or progression. METHODS: Using a 2 stage kinetic chromogenic assay, monocyte tissue factor levels were assessed in normal controls (n=60), patient controls (hernia or cholecystectomy, n=60) and in patients with benign and malignant disease of the bladder (n=73), prostate (n=81), breast (n=83) and colorectum (n=62). This was performed as baseline (resting cells) and after 6 hours incubation with (stimulated) and without (unstimulated) lipopolysaccharide. Each benign disease group was sub-divided into inflammatory and non-inflammatory categories. RESULTS: The relative operating characteristic curve for the lipopolysaccharide-stimulated monocyte tissue factor assay showed sensitivity and specificity for cancer, the area under the curve being 0.71. The control groups and the benign non-inflammatory groups gave similar results and were pooled for further analysis. Each malignant group showed higher monocyte tissue factor levels than the control groups for baseline (P< 0.05) and lipopolysaccharide-stimulated cells (P< 0.05). All benign inflammatory groups apart from breast, showed increased monocyte tissue factor levels over controls for baseline (P< 0.05) and lipopolysaccharide-stimulated cells (P< 0.05). In all cases there was no significant difference between the malignant and the benign inflammatory groups. Monocyte tissue factor levels were related to tumor grade or stage, patients' survival time, serum prostate specific antigen and static bone scan images. Levels were also higher in patients with bladder cancer recurrence and in those who subsequently died. CONCLUSION: Lipopolysaccharide-stimulated monocyte tissue factor assay showed sensitivity and specificity for cancer compared to controls. Monocyte tissue factor levels are raised in malignant groups compared to controls and non-inflammatory diseases but not when compared with inflammatory conditions. Stimulated cells give better discrimination between the groups and may be useful in identifying high risk individuals. Monocyte tissue factor levels were related to tumor progression.

Adult↗
PubMed1999

Urinary tissue factor levels in patients with breast and colorectal cancer.

Activation of blood coagulation is a common complication of cancer in man and experimental animals. The causes of such activation may be multifactorial, but increased production of tissue factor (TF) by the host mononuclear cells may be involved. TF is not only produced by human monocytes (mTF) and tumour cells, but is also found in urine (uTF), where measurements might be clinically important. Using a highly reproducible (intra-assay CV 2.3 per cent and inter-assay CV 8.1 per cent) one-stage kinetic chromogenic assay (KCA) developed by this group, uTF levels were measured in controls [healthy volunteers (n = 57), patients with renal stones and a normal ESR (n = 30)] and in patients with benign and malignant diseases of the breast (n = 94) and large bowel (n = 62). Each benign disease group was sub-divided into inflammatory and non-inflammatory categories. There were no significant differences between the controls and the benign non-inflammatory groups, so they were unified for further analysis. Malignant groups, irrespective of tumour types, showed significantly higher uTF levels than controls (p < 0.001 for breast and p < 0.01 for large bowel). Similarly, breast and colorectal benign inflammatory groups showed significant increases over controls (p < 0.01 and p < 0.001, respectively). Patients with malignant disease showed uTF activity above the upper quartile range of the normal control group for breast, 77.3 per cent, and large bowel, 73 per cent. uTF levels were related to histological tumour grading and were higher in non-surviving patients. In conclusion, uTF levels are raised in malignant and inflammatory disease compared with controls and patients with non-inflammatory conditions. uTF levels may reflect tumour progression.

Adolescent↗
PubMed1999

Urinary tissue factor: a potential marker of disease.

Tissue factor (TF) is the main physiological initiator of blood coagulation and may be important in the biology of a variety of solid malignancies, particularly where angiogenesis is a critical factor. TF is frequently encrypted in the plasma membrane of cells in contact with blood, and is exposed only after stimulation by certain agonists. Cancer cells variably express TF and cancer cell lines which exhibit multidrug resistance contain more TF than parental cells. TF is increased in both tumour-associated macrophages and blood monocytes and has been implicated in abnormal coagulation activation seen in patients with inflammatory conditions and cancer. TF is also found in urine (uTF) in a lipid-associated form, probably of kidney origin. uTF levels can be assayed in a cost-effective manner and may be clinically important, particularly in patients with renal disorders and malignancy. uTF levels are not significantly affected by age, gender or cigarette smoking.

Age Factors↗
PubMed1999

The significance of measuring monocyte tissue factor activity in patients with breast and colorectal cancer.

Monocytes express tissue factor (mTF) in several conditions including cancer where levels may be valuable in assessing tumour presence and progression. Using a two-stage kinetic chromogenic assay (KCA), mTF levels were measured in controls [normal subjects (n = 60) and patients undergoing hernia repair or cholecystectomy (n = 60)], in patients with benign and malignant disease of the breast (n = 83) and of the large bowel (n = 62). This was performed under fresh (resting) conditions and after incubation for 6 h without (unstimulated) and with (stimulated) Escherichia coli endotoxin. The malignant groups showed higher mTF levels than each of the three controls for resting (P < 0.05 breast, P < 0.05 colorectal) unstimulated (P < 0.05 breast, P < 0.05 colorectal) and stimulated cells (P < 0.001 breast, P < 0.01 colorectal). Similarly, the benign inflammatory groups had higher mTF levels than controls for resting (P < 0.05 colorectal), unstimulated (P < 0.05 colorectal) and stimulated cells (P < 0.01 breast, P < 0.01 colorectal). There was no significant difference between malignant and benign inflammatory groups in each organ. mTF levels showed an increase corresponding to that of histological tumour progression and were higher in non-surviving patients. In conclusion, mTF levels are raised in malignant and inflammatory disease compared to controls and patients with non-inflammatory conditions. Stimulated cells give better discrimination between the groups and may be of value in identifying high risk individuals. mTF levels showed an association with tumour grade or stage and the patients' survival time.

Breast Neoplasms↗
PubMed1999

Monocyte tissue factor levels in patients with urological tumours: an association between tumour presence and progression.

OBJECTIVE: To examine the hypothesis that increased monocyte tissue factor (mTF) levels may reflect urological tumour presence and progression. PATIENTS, SUBJECTS AND METHODS: Using a two-stage kinetic chromogenic assay, mTF levels were measured in 60 controls (normal subjects [60] and patients awaiting hernia repair or cholecystectomy [60]), patients with benign and malignant disease of the bladder (73), or prostate (81), and in patients with and without recurrent malignant disease of the bladder (30). The levels were assessed under fresh resting conditions (baseline) and after incubation for 6 h without (unstimulated) and with (stimulated) Escherichia coli endotoxin. Each benign disease group was subdivided into inflammatory and non-inflammatory categories. RESULTS: Patients with bladder and prostate malignancy showed significantly higher mTF levels than did each control for baseline and stimulated cells. The benign inflammatory groups for both organs had significantly higher mTF levels than had each control for baseline cells. There was no difference between malignant and benign inflammatory groups. Stimulated mTF levels showed better discrimination between the study groups. The mTF levels were associated with histological tumour progression, serum prostate specific antigen level and static bone scan images. Levels were also higher in patients with bladder cancer recurrence than in those with a normal check cystoscopy. CONCLUSION: Stimulated mTF levels are raised in malignant and inflammatory disease compared with controls and patients with non-inflammatory conditions, and give maximal discrimination between these groups. mTF levels showed an association with tumour grade and other markers of tumour progression.

Biomarkers, Tumor↗
PubMed1999

Tissue factor assays as diagnostic tools for cancer? Correlation between urinary and monocyte tissue factor activity.

Monocyte and urinary tissue factors (mTF and uTF) are both elevated in a number of pathologic conditions, including cancer. This study validates the best available uTF and mTF assays as diagnostic tools for cancer and examines if uTF levels reflect monocyte activation. Using kinetic chromogenic assays for uTF and mTF (measured on fresh resting cells [baseline], unstimulated cells, and lipopolysaccharide [LPS]-stimulated cells), we assessed TF levels in normal individuals, surgical controls, and patients with benign and malignant diseases. Each benign disease group was stratified as inflammatory or noninflammatory. Controls and benign noninflammatory results were indistinguishable. The malignant and inflammatory groups showed raised uTF levels over controls (p < 0.001). mTF levels differ similarly. For mTF and uTF assays, there was no significant difference between the malignant and inflammatory groups. The relative operating characteristic (ROC) curve plots sensitivity against false positive rate (1-specificity) for all possible cutoff values of a diagnostic test. Assay performance is assessed as the area under the curve (AUC). The ROC curve for the uTF assay displayed both sensitivity and specificity for cancer, the AUC being 0.83. Of the three mTF levels, LPS-stimulated cells gave the optimum curve (AUC = 0.71). uTF showed a weak to moderate association with mTF levels but correlated best and was statistically significant when compared with levels in the LPS-stimulated cells. uTF represents an intrinsic, kidney-derived, physiologic concentration rather than that of preactivated or postactivated monocytes. In conclusion, both uTF and LPS-stimulated mTF levels showed sensitivity and specificity in detecting cancer and inflammatory diseases. However, the two forms of TF appear to be independently derived.

Adolescent↗
PubMed1999

Functional and structural properties of urinary tissue factor.

BACKGROUND: We have previously explored the clinical significance of urinary tissue factor (uTF) in patients with glomerulonephritis (GN) and malignancy. However, the functional and structural properties and putative cell of origin of uTF are poorly documented. In these studies we investigate these aspects of uTF. METHODS: Functional and structural properties of uTF were investigated using a one stage kinetic chromogenic assay, an enzyme-linked immunoabsorbent assay (ELISA) and transmission electron microscopy (TEM) on urine samples collected from healthy controls (n=69). The distribution of uTF and anionic phospholipid in the kidney were studied in sections from normal areas of nephrectomy specimens, using an immunoperoxidase technique. These were stained for tissue factor (TF) antigen and recombinant Annexin V. RESULTS: We found uTF to be present on subcellular particles as visualized by TEM. These particles contained anionic phospholipid as evidenced by binding to Annexin V fluorescein isothiocyanate (FITC). Although TF is present in urine in a functional and antigenic form no association was observed between the two. Using immunoperoxidase-based techniques, the cytoplasm of both distal and proximal tubules (but not glomerular cells) was positive for TF antigen and Annexin V. CONCLUSION: uTF is found on subcellular particles which provide lipid for its functional activity. Both uTF and its associated vesicles are found in the renal tubular cells.

Annexin A5↗