Characterization, Properties and Antimicrobial Activity of Radiation Induced Phosphorus-Containing PVA Hydrogels

Function modification of polyvinyl alcohol (PVA) having phosphorus-containing heterocyclic compounds is believed to have thermal and biological applications in the area of polymers. The synthesis of phosphorus-containing PVA (P-PVA) was performed using γ-radiation. The chemical structure of the composite polymer is confirmed by spectroscopic techniques of FT-IR, 1H, 13C, and 31P-NMR. Photosensitive properties of polymers were investigated by ultraviolet spectroscopy. Thermal studies are assigned using the Differential Scanning Calorimeter (DSC) and thermogravimetric analysis (TGA). Data display that P-PVA has more thermal stability than PVA. The surface morphology of the prepared hydrogels was performed using scanning electron microscopy (SEM). Quantitative elemental analysis of the P-PVA hydrogel was done through energy-dispersive X-ray spectroscopy (EDX). Antimicrobial activity of the prepared hydrogels using different fungi such as Aspergillus fumigatus, Geotrichum candidum, Candida albicans, and Syncephal-astrum racemosum, in addition to bacteria such as Staphylococcus aureus, Bacillis subtilis (as gram-positive bacteria), Pseudomonas aeruginosa, and Escherichia coli (as gram-negative bacteria), was studied. The phosphorus-contained PVA hydrogels were found to have antimicrobial activity against various fungi and bacteria compared to pure PVA hydrogels.

Novel Anticancer Fused Pyrazole Derivatives as EGFR and VEGFR-2 Dual TK Inhibitors

EGFR and VEGFR-2 represent promising targets for cancer treatment as they are very important in tumor development as well as in angiogenesis and metastasis. In this work, 6-amino-4-(2-bromophenyl)-3-methyl-1,4-dihydropyrano[2,3-c]pyrazole-5-carbonitrile 1 and (E)-4-(2-Bromobenzylidene)-5-methyl-2,4-dihydro-3H-pyrazol-3-one 11 were selected as starting materials to synthesize different fused pyrazole derivatives; dihydropyrano[2,3-c]pyrazole 1, 2, 7–9, and 15, pyrazolo[4′,3′:5,6]pyrano[2,3-d]pyrimidine 3–6, pyrazolo[3,4-d]pyrimidine 12 and 13, and pyrazolo[3,4-c]pyrazole 14 derivatives were synthesized to evaluate their anticancer activity against HEPG2 human cancer cell lines compared to erlotinib and sorafenib as reference drugs. Seven compounds 1, 2, 4, 8, 11, 12, and 15 showed nearly 10 fold higher activity than erlotinib (10.6 μM) with IC₅₀ ranging from 0.31 to 0.71 μM. In vitro EGFR and VEGFR-2 inhibitory activity were performed for the synthesized compounds, and the results identified compound 3 as the most potent EGFR inhibitor (IC₅₀ = 0.06 μM) and compound 9 as the most potent VEGFR-2 inhibitor (IC₅₀ = 0.22 μM). Moreover, compounds 9 and 12 revealed potent dual EGFR and VEGFR-2 inhibition, and these results were supported by docking studies of these two compounds within the active sites of both enzymes.

Anticancer Evaluation and Docking Study of New Bifunctional Phthalazine Derivatives

Materials and Methods:

The newly synthesized compounds were characterized by spectroscopic measurements and were tested for their in vitro anticancer activity by MTT assay against human liver cancer cell line. Docking study of all the synthesized compounds was performed within the active site of the enzyme VEGFR-2 (Vascular Endothelial Growth Factor Receptor-2).

Results:

The quinazoline derivative 12 emerged as the most potent compound in this study with an IC50 value of 5.4 µM. Docking study showed that the synthesized compounds were fit in the VEGFR-2 active site almost at the same position of sorafenib and vatalanib with comparable docking scores (-15.20 to -8.92 was kcal/mol).

Conclusion:

we have synthesized a novel series of phthalazine derivatives and evaluated their potential anticancer activity against HEPG2 cell line. The quinazoline derivative 12 emerged as the most potent compound in this study with an IC50 value of 5.4 µM. The SAR and docking studies pointed out that rigidification of the structure resulted in better activity and better binding within the active site of VEGFR-2 as in compounds 3, 5, 6 and 12. These results introduced new phthalazine derivatives having promising activity which could lead to the development of more potent anticancer agents.

Efficient procedure with new fused pyrimidinone derivatives, Schiff base ligand and its La and Gd complexes by green chemistry

Synthetic strategies were developed for the construction of some newer more potent derivatives of thiobarbituric acid and its Schiff base metal complexes in both bulk and at the nanoscale.

Intraoperative and delayed wound approximation in closure of skin defects in different areas

OBJECTIVE

Wound approximation device is an interesting reconstructive option but not well popularised. In this study we present a simple device that can be used for immediate or delayed closure of large dermal wounds in different anatomical areas.

METHOD

Patients with acute and chronic wounds were recruited and underwent immediate intra-operative wound approximation and/or delayed wound approximation, with a home-made wound approximation device.

RESULTS

Approximation time in the immediate closure group ranged from 20-140 minutes. Satisfactory scars were obtained in 19 patients (76%) and adherent scars developed in 6 patients. Delayed wound approximation was used successfully in closure of 9 defects.

CONCLUSION

This simple dermal wound approximation device can be used intraoperatively to successfully close large difficult wounds, located on the trunk and thigh, with minimal complications. The device can also be used to approximate delayed wounds located in regions where closure is particularly problematic, like the lower leg, foot, and scalp. Some modifications of the device are needed to improve its safety and efficacy. Wound tension is detrimental to adequate wound healing and tensile strength, another basic principle that should not be overlooked to avoid wound dehiscence. Wound approximation is adding to reconstructive options, not replacing them, and they must always be considered.

Design and synthesis of some new thiophene, thienopyrimidine and thienothiadiazine derivatives of antipyrine as potential antimicrobial agents

4-acetamide Pyrazolone 2 was synthesized by acetylation of 4-amino antipyrine 1 in excellent yield. 4-acetamide pyrazolone 2 was exploited as a starting material for the syntheses of hitherto unknown different types of new heterocyclic compounds incorporating the antipyrine moiety which expect highly biological activity against various microorganisms. Thus, Claisen condensation of 4-acetamide pyrazolone 2 with diethyl oxalate have been utility to afford new 4-oxaloacetyl antipyrine 3, which upon hydrazinolysis of the ester function to obtain the acetohydrazide derivative 18 which used as starting material to synthesize 1,2,4-triazol 19 and hydrazone 20 derivatives. 4-aminothiophene carboxylate derivatives 6, 7 were synthesized by utility of Gewald reaction. On the other hand, Michael type addition of the enolate ion of acetyl functions in acetamide pyrazolone 2 to the activated double bond in arylidenemalonoester to furnish pyrane derivative 9 was done. Finally, 4-acetamide pyrazolone 2 was treated with aromatic substituted aldehyde to exhibit thiophenacrylamide derivative 10. Compound 6 gave characteristic reaction for enaminonitriles, thus, the behavior of o-aminoester of 4-aminothiophene carboxylate derivative 6 toward electrophilic reagent, one carbon donars, amide and acid was also investigated to afford the correspondence thiophene derivatives 11,12,13,15 and 16. In addition, treatment of carboxamide derivative 16 with thionyl chloride afforded the thienothiadiazine derivative 17. The characterization of all synthesized compounds was done by elemental analysis and spectral studies. Moreover, all the synthesized compounds were tested against antimicrobial activities by the disc diffusion method, which exhibited higher promising biological activities.

Potential of pottery materials in manufacturing radioactive waste containers

Various pottery materials were evaluated for possible use in manufacturing containers for radioactive waste. Their potential was examined from the viewpoints of the effectiveness of disposal and the changes induced in them by gamma rays. Samples of these materials were irradiated with high-energy neutrons and gamma rays in a reactor near its core. the physical and mechanical properties of the materials before and after gamma irradiation (in a 60Co gamma cell) were compared. The study showed that pottery materials are resistant to radiation. Therefore, they were proposed for manufacturing drums for disposal of radioactive waste of high gamma activity.

Utilization of colorimetric and atomic absorption spectrometric determination of aztreonam through ion pair complex formation

Three rapid and sensitive, colorimetric and atomic absorption spectrometric methods were developed for the determination of aztreonam. The proposed methods depend upon the reaction of cobaltthiocyanate (I) or reineckate (II) ions with the drug to form stable ion-pair complexes which extractable with chloroform. The greenish blue and pink color complexes are determined either colorimetrically at lambda(max) 625 and 525 nm for I and II reagents, respectively, or by atomic absorption spectrometry, directly using the organic extracted complex, or indirectly, using the supernatant. The three procedures are applied for the determination of aztreonam in pure and in pharmaceutical dosage forms applying the standard additions technique and the results obtained agreed well with those obtained by the official method.

Proliferation and extracellular matrix production by human infragenicular smooth muscle cells in response to interleukin-1 beta

PURPOSE

Atherosclerotic peripheral vascular disease commonly involves the infragenicular arterial tree. Our study evaluated the effect of interleukin (IL)-1 beta on the proliferation of vascular smooth muscle cells (VSMCs) derived from atherosclerotic infragenicular arteries of human subjects who underwent below-knee amputation, as well as the role of IL-1 beta in VSMCs' production of extracellular matrix components, substances that are important in the transformation of VSMCs from the contractile to the synthetic phenotype. This transformation to the synthetic phenotype is an important step in the formation of the atherosclerotic lesion.

METHODS

Cultures were identified as being of smooth muscle origin through staining with the cytoskeletal marker, alpha-smooth muscle actin. Proliferation assays were performed by seeding confluent cultures of passages 4 to 7 into six-well plates at 10,000 cells per well. After serum starvation, samples were incubated with IL-1 beta (1 ng/ml). Cell number was determined on a daily basis. To study extracellular matrix production, cells were propagated in tissue culture chamber slides in the absence or presence of growth media containing IL-1 beta. After fixation with 100% methanol, each sample was stained with a primary antibody specific for an extracellular matrix component. After staining with the fluorescein-tagged secondary antibody, each sample was examined using immunofluorescent microscopic examination.

RESULTS

The results of our proliferation assays showed that IL-1 beta caused a significant increase in the proliferation of VSMCs at 24, 48, 72, and 96 hours (p < or = 0.003 when comparing IL-1 beta-treated samples with control specimens at each time period using unpaired t test). The number of IL-1 beta-treated cells at 96 hours was double the number present in the control samples (16,033 +/- 238 vs 8102 +/- 824). When compared with control samples, IL-1 beta was found to affect the production of extracellular matrix proteins by infragenicular VSMCs. IL-1 beta caused an increase in the production of fibronectin, a decrease in the production of laminin, and no change in the production of collagen type IV.

CONCLUSIONS

These results suggest that interleukin-1 beta acts as a potent stimulant of the proliferation of human infragenicular VSMCs. IL-1 beta also acts to augment the production of fibronectin by these cells. Fibronectin has been implicated in the phenotypic transformation of VSMCs from the contractile to the synthetic state. Therefore, IL-1 beta may serve as an important regulatory factor in the development of atherosclerosis by stimulating the proliferation of VSMCs and their transformation to the synthetic state, two important steps in the formation of the atherosclerotic lesion.

Transforming growth factor beta 1 inhibits the proliferative effect of insulin on human infragenicular vascular smooth muscle cells

PURPOSE

The distribution of atherosclerotic arterial disease in diabetes mellitus characteristically involves the infragenicular arterial tree including the anterior tibial, posterior tibial, and peroneal arteries. The proliferation of vascular smooth muscle cell (VSMC) is essential in the development of the atherosclerotic lesion. It has long been held that insulin plays a causative role in the formation of the atherosclerotic lesion in diabetes. We studied the role played by insulin in the proliferation of these cells in culture and the interaction of insulin with transforming growth factor beta 1 (TGF beta 1), a factor known for its possible inhibitory effects.

METHODS

We have grown and characterized a line of VSMC harvested from atherosclerotic infragenicular arteries of human subjects undergoing below-knee amputation. The cultures were defined as being of VSMC origin by immunohistochemical staining with alpha-smooth muscle actin. Confluent cultures of passages 4 through 7 were seeded into six well plates at a density of 5000 cells/well. After serum deprivation the cells were exposed to insulin (100 ng/ml) alone or in combination with TGF beta 1 (6 ng/ml).

RESULTS

Our findings indicate that a 48-hour incubation with insulin augments the proliferation of human infragenicular VSMC, producing a 207% increase in cell number when compared with control cells (11,328 +/- 686, n = 56 vs 3682 +/- 182, n = 87; p < 0.0001). The addition of TGF beta 1 in combination with insulin abolished the accelerated growth rate seen in test groups treated with insulin alone (3614 +/- 247, n = 32 vs 11,328 +/- 686, n = 56; p < 0.0001).

CONCLUSION

These results strongly suggest that insulin is a potent stimulant of human infragenicular VSMC proliferation. The mitogenic effect of insulin is inhibited by TGF beta 1, producing proliferation rates comparable to those observed in control cells incubated with serum-free media.

Phenotypic characterization of human smooth muscle cells derived from atherosclerotic tibial and peroneal arteries

PURPOSE

The vascular smooth muscle cell plays a pivotal role in the development of atherosclerosis. The objectives of this study were to characterize smooth muscle cells from the human atherosclerotic tibial artery to determine their phenotypic properties and to examine the contractile reactions of these cells to physiologic and pharmacologic stimuli.

METHODS

After below-knee amputations were performed, vascular smooth muscle cells were harvested and cultivated from tibioperoneal source. Characterization was done with transmission electron microscopy and immunocytochemistry. The contractile properties were determined by observing the response to various stimuli. In addition, segments of vessels harvested were submitted to electron microscopy studies for comparison with the cultured cells.

RESULTS

Immunofluorescent labeling was positive for alpha-smooth muscle actin. Electron microscopy revealed the presence of a thickened basal laminae and large intracellular lipid vacuoles. The earlier passages revealed cells with a large number of microfilaments characteristic of a contractile cell. As later passages were examined, there was a notable change in character with an increasing amount of rough endoplasmic reticulum and Golgi complexes. The increased thickness of the basal lamina in the cultured cells resembled that found in vessel segments studied by electron microscopy. A rapid contraction response was seen when the cells were incubated with angiotensin II, bradykinin, or endothelin. No response was seen with the addition of isoproterenol, nitroglycerin, or nitroprusside, known smooth-muscle relaxants.

CONCLUSION

This model demonstrates the apparent inability of these smooth muscle cells from atherosclerotic tibial arteries to relax to pharmacologic and physiologic stimuli. In addition, as seen by transmission electron microscopy, these cells maintain their atherosclerotic phenotype after multiple passages.

Use of modern craniofacial techniques for comprehensive reconstruction of the acromegalic face

The severe acromegalic patient poses a difficult reconstructive dilemma to the craniofacial surgeon. Significant facial deformities can include frontal bossing, prominent supraorbital ridges, malar flatness, maxillary hypoplasia, mandibular prognathism with class III malocclusion, and macrogenia. Reports on the correction of these deformities are rare. Prior publications describe long hospital stays, weeks of intermaxillary fixation, requirement for a tracheostomy, as well as the need for multiple, staged procedures and interdisciplinary teams. In an effort to extend the advances of modern craniofacial techniques to this group of patients, we performed an extensive reconstruction on a 28-year-old acromegalic patient using a one-stage procedure without the use of intermaxillary fixation and without the added morbidity of a tracheostomy. The procedure addressed the skeletal deformities of the upper face, the midface, and the lower face. The operation was performed by a single plastic surgery team and the patient was extubated in 36 hours and discharged in 6 days. We believe that the use of rigid fixation and the judicious application of modern craniofacial principles can allow a complex yet safe one-stage procedure to reconstruct the acromegalic face. Such an approach showed decreased perioperative morbidity and provided an excellent functional and aesthetic result.

Effect of growth factors on cell proliferation and epithelialization in human skin

The failure of chronic wounds to heal remains a major medical problem. Recent studies have suggested an important role for growth factors in promoting wound healing. We investigated the mitogenic effect of basic fibroblast growth factor (FGF), insulin-like growth factor-1 (IGF-1), and epidermal growth factor (EGF), comparing their effects with those of media alone (MEM) in a human skin explant model. A stable organ culture system for maintaining the histologic structure of human epidermis for 10 days in vitro was developed. DNA synthesis was measured on Days 1, 3, and 7 of organ culture using [3H]thymidine ([3H]thy) uptake and expressed as cpm/mg dry weight (mean +/- SEM). FGF, IGF-1, and EGF were each capable of stimulating [3H]thy uptake on Day 1 of culture (2372 +/- 335 FGF, 2226 +/- 193 IGF-1, 4037 +/- 679 EGF vs 1108 +/- 70 MEM, P < 0.05). IGF-1 and EGF also stimulated [3H]thy uptake on Days 3 and 7 of culture. The organ culture system was further employed to observe epidermal outgrowth. Longest keratinocyte outgrowth from the explant periphery (simulating epithelial regeneration from the wound edge) was observed on Day 7. EGF resulted in maximum stimulation of epithelial outgrowth (440 +/- 80 microns), followed by FGF (330 +/- 56 microns), IGF-1 (294 +/- 48 microns), and MEM (189 +/- 50 microns). We postulate, therefore, that FGF, IGF-1, and EGF are important mitogens for wound healing and that EGF in particular is capable of stimulating epithelialization.(ABSTRACT TRUNCATED AT 250 WORDS)

Adenine nucleotide depletion in cryopreserved human cardiac valves: the "stunned" leaflet interstitial cell population

Preparation protocols for human cardiac valves are intended to minimize cytotoxicity because it has been thought that viable leaflet interstitial cells may enhance homograft durability. Preimplantation factors influencing the status of these cells at the time of transplantation include ischemia, disinfection, and cryopreservation freezing programs. In these experiments, adenine nucleotide quantitation was undertaken to assess metabolic consequences of preparation; preharvest ischemia served as an independent variable to examine the relationship between time of procurement (postmortem) and high-energy phosphate status of the cryopreserved leaflets at thaw. Nucleotides were measured using high-performance liquid chromatography performed on extracts of semilunar cusps from 25 cryopreserved human valves with documented ischemic times. Results indicate total adenine nucleotides (TAN; [ATP] + [ADP] + [AMP], in nmol TAN/mg leaflet protein) are higher (P < 0.05) after < 2 h of harvest ischemia (1.16 +/- 0.36) than with ischemic times of 3-6 h (undetected), 7-12 h (0.18 +/- 0.07), and 13-20 h (0.06 +/- 0.06). Depletion of ATP was similar, with many leaflets devoid of detectable levels. Net utilization of leaflet energy stores demonstrates time dependency when assayed after completed processing. However, relatively elevated catabolites, even with brief ischemia, and infrequently identified ATP, ADP, and AMP, suggest a consumption so accelerated that the following cryopreservation it is virtually independent of procurement-associated ischemia. We conclude resumption of a functional cell population obligates significant de novo phosphoanhydride boned reformation or a repopulation of dead/dying interstitial cells from a subset surviving the apparently severe rigors of valve preparation.

Dual structural and functional phenotypes of the porcine aortic valve interstitial population: characteristics of the leaflet myofibroblast

The cellular properties of semilunar cardiac valve leaflets may be more complex than previously assumed. In particular, the cells of the leaflet matrix which are likely critical to proper cusp function are a poorly described population to date. We hypothesized that, similar to the matrix cells of atrioventricular valves, aortic valve leaflet interstitial cells (AoLIC's) possess characteristics of both fibroblasts (matrix secretion) and smooth muscle cells (contraction). Porcine AoLIC's were structurally examined for contractile and stress fiber protein assemblies using transmission electron microscopy and immunocytochemistry. Contractile function in response to vasoactive stimuli was directly assessed using AoLIC's cultured on flame-polymerized silicone, with cell contraction identified by the appearance of wrinkles in the substratum after challenge with each agent. The structural analyses showed cellular microfilaments were often organized into various contractile arrangements including polygonal networks, and that AoLIC's are rich in smooth muscle-specific alpha-actin. Incomplete basal laminae often associated with myofibroblasts were observed. Contraction experiments indicated a responsivity of similar latency, but variable peak and duration to 10(-7) M L-epinephrine, 3.2 x 10(-7) M angiotensin II, 110 microM carbachol, 50 mM KCl, 3.2 x 10(-7) M bradykinin, 110 microM isoproterenol, and 5 x 10(-7) M endothelin I. Soluble and insoluble matrix secretion was confirmed with FITC-conjugated monoclonal antibodies to chondroitin sulfate, fibronectin, and prolyl-4-hydroxylase. These data show that the AoLIC's are best designated as myofibroblasts. The unusual features of the myofibroblast may be central to lifelong aortic leaflet durability.

Inhibition of adenosine deaminase and nucleoside transport. Utility in a model of homograft cardiac valve preimplantation processing

Human cardiac valves are increasingly used in the reconstruction of ventricular outflow tracts and offer performance advantages over porcine and mechanical prostheses; the durability of these replacements has been associated with leaflet interstitial cell viability and a presumed sustained function after implantation. Preimplantation tissue preparation entails sequential steps that are potentially cytotoxic and may therefore affect functional cell survival at thaw. We defined the metabolic consequences of each interval using semilunar cusps from 118 porcine valves to model a homograft preparation with 40 minutes of fixed cadaveric (harvest) ischemia. Fifty-eight valves served as controls and were first processed according to standard cryopreservation protocol; nucleosides were extracted at the end of each step to differentiate independent contributions to high-energy phosphate depletion. Sixty simultaneously harvested leaflets were administered the nucleoside transport inhibitor p-nitrobenzy-thionosine (NBMPR) and the adenosine deaminase inhibitor erythro-9-(2-hydroxy-3-nonyl) adenine (EHNA) at procurement, to attempt adenosine salvage and restitution of processing-incurred adenine nucleotide losses. High-performance liquid chromatography was used to compare adenosine triphosphate, diphosphate, and monophosphate and diffusible nucleopurines of the control and EHNA/NBMPR-treated groups. Control results indicate that disruption of the adenosine triphosphate-diphosphate cycle occurs independently with antibiotic disinfection and cryopreservation. However, throughout all preparation steps, adenine nucleotides were maintained at harvest (baseline) concentrations in the EHNA/NBMPR valves. This suggests that salvage therapy may protect a significant number of cells from net high-energy phosphate catabolism. If, with further study, the durability of transplanted valves is concluded to benefit from retained leaflet interstitial cell viability, such enhancement of metabolic tolerance to the obligatory processing may facilitate functional recovery.

High energy phosphate depletion in leaflet matrix cells during processing of cryopreserved cardiac valves

Preimplantation preparation of cardiac valves includes three major steps: (1) harvesting with accompanying ischemia (warm time from cessation of donor heart beat), (2) antibiotic disinfection, and (3) controlled-rate cryopreservation. To define the interdependent injury effects of these manipulations on leaflet matrix cells and specifically the potential for prolonged harvest-related ischemia to predispose greater injury by the subsequent steps, 96 semilunar valves were harvested from pigs in a manner analogous to human heart valve retrievals and randomly allocated to study groups as follows: 48 control valves were exposed to increasing harvested-related ischemic times, (2, 6, 12, 24 hr) and immersed in liquid nitrogen to arrest metabolic activity (i.e., prior to cryopreservation) and conclude the ischemia; another 48 were similarly harvested, subjected to identical ischemic times, then disinfected in 4 degrees C RPMI medium with standard antibiotics for 24 hr and dimethylsulfoxide cryopreserved at -1 degrees C/min to -170 degrees C (i.e., formal cryopreservation protocol). At thawing, each valve was extracted in 12% trichloroacetic acid and assayed by high performance liquid chromatography for components of the adenine nucleotide pool including ATP, lower energy nucleotides (total adenine nucleotides, [TAN] = [ATP] + [ADP] + [AMP]), adenosine, and the diffusible purines. Results are reported as nanomoles metabolite/milligram of leaflet cell protein (Lowry) and reflect a maintenance of total high energy phosphates in the control groups (5.41 +/- 0.29 nmole TAN at 2 hr; 8.34 +/- 0.67 nmole TAN at 24 hr), which fell significantly in all cryopreserved groups (1.27 +/- 0.33 nmole TAN at 2 hr; 0.34 +/- 0.22 nmole TAN at 24 hr).(ABSTRACT TRUNCATED AT 250 WORDS)