Determination of Ferrous Oxide Nanoparticles Minimum Inhibitory Concentration against Local Virulent Bacterial Isolates.

The improvement of multi-resistance properties of the bacterial pathogen has recently been discussed as an emerging issue. In this regard, iron oxide nanoparticles have attracted the researchers' attention due to their wide application in the realm of medicine. Iron oxide nanoparticles have a high specific surface area that enables them to interact with the bacterial surface structure and has considerable antibacterial activity. The current study aimed to synthesize a novel antimicrobial agent from iron oxide nanoparticles and determine its minimum inhibitory concentration (MIC) on different gram-positive and negative variant bacterial strains isolated and characterized from the infected urinary tract of Iraqi elderly patients. This study was conducted from September 2020 to December 2020 on 75 urine samples collected from the infected urinary tract of elderly patients in the ages range of 60-75 years admitted to Al-Yarmouk Medical Hospital, Baghdad, Iraq. Isolation of bacterial isolates was carried out using differential and selective media. Afterward, they were characterized and confirmed using different biochemical tests and VITEK 2 system, respectively. Magnetic nanoparticles were fabricated by co-precipitation of ferric ions (Fe3+) and ferrous ions (Fe2+) in presence of ammonium hydroxide solution (25%). The characterization of synthesized nanoparticles was performed subsequently using UV-VIS spectroscopy analysis, Scanning Electron Microscope (SEM), Fourier transform infrared spectroscopy analysis, X-ray Diffraction analysis (XRD), and Energy-dispersive X-ray spectrum (EDX). The MIC of synthesized sonicated Fe3O4NP against different bacterial strains was determined using the broth culture dilution method through making serial dilutions of 50, 100, 200, 400, 500, 600, 800, 900 µg/ml from a 5mg/ml nanoparticle stock solution. Afterward, the lowest concentration of nanoparticles required to arrest the growth of bacteria was determined through the colony-forming unit of each treated bacteria on brain heart infusion agar. In total, 17bacterial isolates were identified from the infected urinary tract, five bacterial isolates (E. coli, Pseudomanas aeruginosa, Staphylococcus aureus, Enterococcus faecalis, and Micrococcus luteus). In addition, two Proteus mirabilis strains were identified separately and were tested against synthesized Fe3O4NP to determine the MIC. The novel synthesized antibacterial agent showed excellent bioactivity, compared with controls (consisting of bacterial suspension without ferrous oxide nanoparticles), and the synthesized antibacterial agent was considered significantly active against all the bacterial strains at a p-value less than 0.05. The Fe3O4NP were active against gram-negative more than gram-positive bacteria. The MIC of synthesized and characterized Fe3O4NP wasapplied on seven gram-positive and negative bacterial isolates using bacteria-Fe3O4NP complex. Significant effects were observed on all strains, compared with controls, and this complex could significantly inhibit gram-negative more than gram-positive bacteria.

Molecular and cellular mechanisms of lymphangiogenesis.

Lymphangiogenesis is the growth and formation of new lymphatic vessels. It occurs in normally developing tissues and in pathological processes like inflammation, wound healing, lymphoedema and in cancer. New molecular markers that are specific to the lymphatic endothelium include: podoplanin, prox-1 and LYVE-1. The molecular mechanisms of lymphangiogenesis are not clear, but vascular endothelial growth factors (VEGF-C and VEGF-D) within tumours may simulate endothelial cells within tumour tissues to grow and generate new lymphatics. We report the current knowledge of molecular and cellular mechanisms of lymphangiogenesis.

Interleukin 7 upregulates vascular endothelial growth factor D in breast cancer cells and induces lymphangiogenesis in vivo.

BACKGROUND: Interleukin (IL) 7 is known to stimulate growth of breast cancer cells in vitro. It has been recently associated with node-positive tumours and with poor survival in breast cancer. The effects of IL-7 on the lymphangiogenic properties of breast cancer cells were explored. METHODS: The effects of IL-7 on the expression of vascular endothelial growth factors (VEGFs) in MDA MB-231, MCF-7 and BT-483 cells were analysed by reverse transcriptase-polymerase chain reaction and western blotting. An in vivo lymphangiogenesis model using nude mice was developed. The newly generated microtubules were stained with anti-von Willebrand factor and anti-LYVE-1 (lymphatic vessel endothelial hyaluronan receptor) antibodies. RESULTS: All VEGFs (VEGF-A, -B, -C and -D) were expressed in breast cancer cells, but at different levels. IL-7 increased the expression of VEGF-D at both mRNA and protein levels in MCF-7 and MDA MB-231 cells. In the in vivo model, IL-7 significantly induced the formation of lymphatic LYVE-1-positive, but not vascular von Willebrand factor-positive, microtubules (P = 0.021 versus sections without IL-7). CONCLUSION: IL-7 induced the lymphangiogenic properties of breast cancer cells, probably by upregulation of VEGF-D. This might have a significant impact on the lymphatic spread of breast cancer.

Lymphangiogenesis and its role in cancer.

In many tumour types, lymphatic vasculature serves as a major route for tumour metastasis. The dissemination of malignant cells to the regional lymph nodes is an early step in the progression of many solid tumours and is an important determinant of prognosis. Lymphangiogenesis (formation of new lymphatic vessels) is thought to be crucial for cancer cells to metastasise to the regional lymph nodes. However research in this important process has been neglected largely due to the lack of molecular markers specific to the lymphatic endothelium. Recently, several specific markers have been identified including LYVE-1, podoplanin and prox-1. Although the biology of lymphangiogeneis, particularly its regulation, is still far from clear, it is now well established that tumours are lymphangiogenic i.e. they could induce the generation of their own lymphatics and metastasise to the regional lymph nodes. It is thought that the interruption of the main signalling pathways involved in this process could help to prevent lymphatic spread of many tumours. Furthermore, understanding the molecular mechanisms in lymphangiogenesis might help to develop new therapeutic strategies against cancer lymphatic spread. Here, we reviewed the literature in regards to the biology of lymphangiogenesis, its molecular regulation, lymphatic markers and the significance in human solid tumours.

Aberrant expression of interleukin-7 (IL-7) and its signalling complex in human breast cancer.

Interleukin-7 (IL-7), a haematopoietic growth factor, is known to induce the differentiation and proliferation of some haematological malignancies including certain types of leukaemias and lymphomas. However, little is known about its role in solid tumours, including breast cancer. In this study, the expression level of IL-7, IL-7 receptor (IL-7R) and their downstream signalling molecules, including the Janus kinases (Jak-1 and Jak-3), phosphoinositide 3-kinase (PI3-K) and signal transducers and activators of transcription (Stat-5) were analysed using the reverse transcriptase-polymerase chain reaction (RT-PCR), real-time quantitative PCR and immunohistochemistry in a cohort of patients with breast cancer. The results were analysed in relation to tumour grade, TNM stage, patients' prognosis (using the Nottingham Prognostic Index (NPI)) and survival. The levels of expression of IL-7, IL-7R, Jak-1, Jak-3, PI3-K and Stat-5 were significantly higher in the most aggressive tumours. With the exception of Stat-5 expression, the transcript copies of IL-7 and all other signalling molecules were higher in patients with the worst prognoses (NPI3) and in patients who died from breast cancer after 72 months of follow-up. This aberrant expression of IL-7 and its signalling intermediates in invasive breast cancers could have significant diagnostic and prognostic implications. Measuring these molecules in breast cancer tissues may provide, for the first time, important molecular indicators of tumour differentiation, aggressiveness, nodal status, prognosis and patient survival.

Interleukin 7 induces the growth of breast cancer cells through a wortmannin-sensitive pathway.

BACKGROUND: Interleukin (IL) 7 is a growth factor able to induce the growth and development of certain haematopoietic malignancies including lymphoma and leukaemia. Its effects on solid tumours, including breast cancer, are unknown. This report concerns the effect of IL-7 on the growth of breast cancer cells. METHODS: Reverse transcription-polymerase chain reaction, western blotting and immunoprecipitation were used to detect to detect IL-7 and its receptor (IL-7R) in breast cancer cell lines MDA MB-231 and MCF-7. These cells were treated with various concentrations of human recombinant IL-7 over specified intervals. Changes in growth were assessed using colorimetric and fluorescence-based technologies. Selective IL-7 downstream signalling inhibitors (wortmannin, JAK-3 inhibitor 1, piceatanol and AG 490) were use to clarify the pathways through which IL-7 may affect breast cancer growth. RESULTS: IL-7 significantly accelerated the growth of MDA MB-231 cells and MCF-7 cells (P = 0.004 and P = 0.012, respectively, in PicoGreenassay). The maximum effects were observed after incubation for 72 h. The stimulatory effect of IL-7 on cell growth was completely eliminated in the presence of wortmannin (P = 0.001 and P = 0.003 versus no inhibitor in MDA MB-231 and MCF-7 cells, respectively) and JAK-3 inhibitor 1 (P < 0.001 versus no inhibitor in both cell lines), but not in the presence of piceatanol and AG 490. CONCLUSION: IL-7 induced the growth of breast cancer cells in vitro through a wortmannin-sensitive pathway. This may have an important impact on research into breast cancer development and progression.

Interleukin-7 (IL-7) and IL-7 receptor (IL-7R) signalling complex in human solid tumours.

Interleukin-7 (IL-7) plays an important role in the normal development and maintenance of the human immune system. Its effects are mediated via its receptor, IL-7R. Ligand-receptor engagement results in a cascade of phosphorylation events mediated by various molecules including the Janus kinases (Jak1 and Jak3), PI3-kinase, Stats (signal transducers and activators of transcription) and other molecules. The activation of IL-7 signalling pathway results in survival, proliferation, differentiation and maturation of haematopoietic cells including B and T lymphocytes. Although the relationship of IL-7 with the development and differentiation of some haematological cancers like leukaemias and lymphomas is well recognised, little is known about it involvement with solid tumours. There are several studies that have revealed IL-7/IL-7R expression in epithelial systems and some human solid epithelial tumours. Furthermore, IL-7 can be produced by some human tumour cells and involved in tumour development and progression. In this review article we have summarised the main biological activities of IL-7 and its downstream signalling complex in relation to some human solid malignancies.

Smoking--do vascular surgeons practise what they preach?

Smoking is a major health problem in Great Britain and cigarette consumption is rising. Although there are studies concerning the smoking habits of hospital physicians, nurses and oral and maxillofacial surgeons, little is known about the smoking habits of vascular surgeons and the advice given by them to their patients. A questionnaire survey was conducted involving 422 members of the Vascular Surgical Society of Great Britain and Ireland. The response rate was 74%. The median age of responders was 51 years (range, 32-69 years) of whom 98% were men. Of responders, 98% routinely advise patients to stop smoking, 10% advise nicotine gum/patch, 39% provide antismoking information sheets, 11% are involved in an antismoking clinic/group and 74% check to see whether patients continue to smoke. The majority of responders would be prepared to offer revascularisation in patients who continue to smoke. Only 8 surgeons (3%) would not advise revascularisation in this group of patients. Only 10% of respondents were current smokers, 37% were ex-smokers and 53% had never smoked. Vascular surgeons, therefore, seem to practise what they preach.

Changes in nasal epithelium in patients with severe chronic sinusitis: a clinicopathologic and electron microscopic study.

OBJECTIVE: Defective ciliary ultrastructure and impaired mucociliary clearance play an important role in the development of respiratory disease and sinusitis. Changes in the ciliary ultrastructure of the sinonasal epithelium have been documented in patients with primary ciliary dyskinesia. However, secondary ciliary dyskinesias and epithelial cytopathologic changes have been underappreciated as a consequence of respiratory dysfunction and chronic sinusitis. STUDY DESIGN: Thirty-two patients with severe chronic sinusitis were evaluated for ciliary and epithelial abnormalities. MATERIALS AND METHODS: Fourteen patients (44%) were children who underwent full allergy, sweat, and immunologic workups. Eighteen patients (56%) were adults who had severe refractory sinusitis and had failed previous sinus surgery. All patients underwent nasal epithelium biopsies of the middle turbinate and evaluation by light and transmission electron microscopy. RESULTS: Ciliated cells were found in 23 patients (72%) with 9 patients (28%) having no cilia. Foci of normal ciliated epithelium were found in only 19% of the patients, often in epithelial invaginations. Variable numbers (usually a minor population) of cilia in 20 cases (87%) exhibited ultrastructural defects including compound cilia and microtubule and dynein arm defects. All of the patients showed variable loss of differentiated epithelial cells ranging from denuded epithelium to basal cell hyperplasia often associated with squamous metaplasia, secondary to chronic sinonasal disease. The lamina propria was often edematous with dilated capillaries, plasma cells, lymphocytes, and hyperplastic seromucous glands. CONCLUSIONS: This study demonstrates that ciliary dyskinesias are primarily the result rather than the cause of chronic sinusitis. Patients with chronic sinusitis of uncertain origin exhibit a prominent loss of differentiated epithelial cells, as well as ciliary defects, most of which are likely to be secondary to the chronic disease process. These changes slow down mucociliary clearance and lead to a vicious cycle leading to chronicity.

Green tea regulates cell cycle progression in oral leukoplakia.

BACKGROUND: A complete in vitro multi-stage carcinogenesis model for oral cancer was developed to examine chemopreventive strategies. In the present study, the effects of EGCG [(-)-epigallocatechin-3-gallate], the major constituent of green tea, is being examined to understand mechanisms of action. METHODS: Effects of EGCG on the cell populations were examined with growth assays, cell cycle analysis, and western blots for retinoblastoma protein (pRB). RESULTS: In each cell type, EGCG inhibited growth, with a decrease in efficacy as cells progressed from normal to cancer. A G1 block was induced with an increase in the underphosphorylated form of pRB; EGCG-induced inhibition was not permanent, cells recovered, and no resistance developed. CONCLUSIONS: Our multistage carcinogenesis model for chemoprevention was effective in defining the chemopreventive value of EGCG. The observation that cancerous oral epithelium was less responsive than normal or dysplastic tissues has implication in the use of this agent, and the mechanisms responsible for this result remain to be defined.

Native fluorescence spectroscopy of normal and malignant epithelial cells.

Native fluorescence spectroscopy of normal human oral and malignant epithelial cells was studied under uv excitation. Differences were observed in the excitation spectra between normal and malignant epithelial cells for 340 nm emission. The observed differences may be utilized for both discrimination and changes associated with the amino acid residues in the cellular proteins.