Nanoporous Anodic Alumina Surface Modification by Electrostatic, Covalent, and Immune Complexation Binding Investigated by Capillary Filling

The fluid imbibition-coupled laser interferometry (FICLI) technique has been applied to detect and quantify surface changes and pore dimension variations in nanoporous anodic alumina (NAA) structures. FICLI is a noninvasive optical technique that permits the determination of the NAA average pore radius with high accuracy. In this work, the technique is applied after each step of different surface modification paths of the NAA pores: (i) electrostatic immobilization of bovine serum albumin (BSA), (ii) covalent attachment of streptavidin via (3-aminipropyl)-triethoxysilane and glutaraldehyde grafting, and (iii) immune complexation. Results show that BSA attachment can be detected as a reduction in estimated radius from FICLI with high accuracy and reproducibility. In the case of the covalent attachment of streptavidin, FICLI is able to recognize a multilayer formation of the silane and the protein. For immune complexation, the technique is able to detect different antibody-antigen bindings and distinguish different dynamics among different immune species.

In Vitro Biocompatibility of Surface-Modified Porous Alumina Particles for HepG2 Tumor Cells: Toward Early Diagnosis and Targeted Treatment

Porous alumina photoluminescence-inherent particles are produced and proposed for the development of biomarkers detectors and localized treatment of HepG2 cells. Nanoporous alumina particles (NPAPs) are amorphous, consist of hexagonally ordered nanometric pores in an alumina matrix, have high chemical stability in physiological pH, and exhibit a high inherent photoluminescence in the visible spectrum independently of their size, selectable from nanometers to tens of micrometers. The surface of NPAPs is chemically modified using two different functionalization methods, a multistep method with (3-aminopropyl)triethoxysilane (APTES) and glutaraldehyde (GLTA) and a novel simplified-step method with silane-PEG-NHS. Fourier Transform infrared spectroscopy analysis confirmed the proper surface modification of the particles for both functionalization methods. HepG2 cells were cultured during different times with growing concentrations of particles. The analysis of cytotoxicity and cell viability of HepG2 cells confirmed the good biocompatibility of NPAPs in all culture conditions. The results prove the suitability of NPAPs for developing new label-free biomarker detectors and advantageous carriers for localized drug delivery.

Protein attachment to nanoporous anodic alumina for biotechnological applications: influence of pore size, protein size and functionalization path

Nanoporous anodic alumina (NAA) is a material with great interest in nanotechnology and with promising applications to biotechnology. Obtaining specific and regularly functionalized NAA surfaces is essential to obtain meaningful results and applications. Silane-PEG-NHS (triethoxysilane-polyethylene-glycol-N-hydroxysuccinimide) is a covalent linker commonly used for single-molecule studies. We investigate the functionalization of NAA with silane-PEG-NHS and compared with two common, but not single-molecule, grafting agents, APTMS (3-aminopropylotrimethoxysilane) as an electrostatic linker, and APTMS-GTA (3-aminopropylotrimethoxysilane-glutaraldehyde) as covalent. Another outcome of this study is to show how two proteins (collagen and bovine serum albumin, BSA) with different properties differentially arrange for different functionalizations and NAA pore sizes. FTIR is used to demonstrate the surface modification steps and fluorescence confocal microscopy reveals that silane-PEG-NHS results in a more homogeneous protein distribution in comparison to the other linkers. Reflection interference Fourier transform spectroscopy confirms the confocal fluorescence microscopy results and permits to estimate the amounts of linker and linked proteins within the pores. These results permit to obtain uniformly chemical modified NAA supports with a great value in biosensing, drug delivery and cell biology.

Gold-coated ordered nanoporous anodic alumina bilayers for future label-free interferometric biosensors

A cost-effective label-free optical biosensor based on gold-coated self-ordered nanoporous anodic alumina bilayers is presented. The structure is formed by two uniform nanoporous layers of different porosity (i.e., a top layer with large pores and a bottom layer with smaller pores). Each layer presents uniform pore size, regular pore distribution, and regular diameter along its pore length. To increase and improve the output sensing signals, a thin gold layer on the top surface was deposited. The gold layer increases the refractive index contrast between the nanoporous alumina layer and the analytical aqueous solution, and it results in a greater contrast in the interferometric spectrum and a higher sensitivity of the structure. From this structurally engineered architecture, the resulting reflectivity spectrum shows a complex series of Fabry-Pérot interference fringes, which was analyzed by the reflective interferometric Fourier transform spectroscopy (RIFTS) method. To determine the performance of this structure for biosensing applications, we tested bovine serum albumin (BSA) as the target protein. The results show a significant enhancement of the RIFTS peak intensity and position when a gold layer is on the top surface.

Targeting the extrinsic apoptotic pathway in endometrial carcinoma cell lines and tumor cell explants

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Background: Endometrial carcinoma (EC) frequently shows deregulation of the extrinsic apoptotic pathway. One of the critical regulators of apoptosis resistance in EC is FLIP, under the control of NFkB and a cellular complex composed of CK2, KSR1, and BRAF. Methods: Four different EC cell lines, which are known to exhibit resistance to TRAIL/FAS-induced apoptosis (Ishikawa, KLE, HEC1A, and RL-95) were exposed to various pharmacologic substances that target proteins involved in the regulation of the extrinsic apoptotic pathway and receptor tyrosine kinases including bortezomib, sorafenib, sunitinib, DRB, apigenin, MG-132, epoxomicin, and ALLN. Moreover, EC cell lines were subjected to down-regulation of several of these genes (FLIP, CK2, KSR1, and BRAF) by shRNA. Cell viability and apoptotic morphology was determined. Results were validated in tumor cell explants. Results: Bortezomib induced cell death on EC cells and primary explants to a 70% extent. However, 100% of treated explants and cell lines activated NF-kB instead of blocking its transcriptional potential. Combination of sunitinib plus bortezomib induced 75% fold reduction in NFkB activity and induced a 5% of synergistic increse of apoptotic cell death in Ishikawa cells. Treatment of the four cell lines with TRAIL failed to induce cell death. However, FLIP knock-down sensitized the cells to TRAIL-induced apoptosis (80%). Moreover, down-regulation of CK2, KSR1, and BRAF by pharmacological inhibition, or shRNA, reduced FLIP cellular levels, and induced TRAIL-dependent apoptosis in 70%-100% of EC cell lines tested. Sorafenib induced a dose-dependent cell death in all four cell lines, to a 70%-100% extent at 48 hours. Conclusions: In vitro pharmacologic targeting of the apoptotic pathway effectively induces cell death in EC cell lines. These findings justify clinical trials with these agents in EC.

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Molecular pathology of endometrial carcinoma: practical aspects from the diagnostic and therapeutic viewpoints

This article reviews the main molecular alterations involved in endometrial carcinoma. Five molecular features (microsatellite instability, and mutations in the PTEN, k-RAS, PIK3CA and beta-catenin genes) are characteristic of endometrioid carcinomas, whereas non-endometrioid carcinomas show alterations of p53, loss of heterozygosity (LOH) on several chromosomes, as well as other molecular alterations (STK15, p16, E-cadherin and C-erb B2). The review also covers the phenomenon of apoptosis resistance, as well as the results obtained from cDNA array studies, and the perspectives for targeted therapies. A group of practical applications of molecular pathology techniques are also mentioned: diagnosis of hereditary non-polyposis colon cancer syndrome in patients with endometrial carcinoma; evaluation of precursor lesions; prognosis; diagnosis, particularly for synchronous endometrioid carcinomas of the uterus and the ovaries; and targeted therapies.

Study of microvessel density and the expression of the angiogenic factors VEGF, bFGF and the receptors Flt-1 and FLK-1 in benign, premalignant and malignant prostate tissues

PURPOSE

Vascular endothelial growth factor (VEGF) is an angiogenic factor that stimulates endothelial cell growth and enhances vascular permeability. VEGF exerts its action by binding to the specific cell surface receptors, fms-like tyrosine kinase 1 (Flt-1) and fetal liver kinase 1 (FLK/KDR). In tumor angiogenesis, Vascular endothelial growth factor stimulates endothelial cells to produce Basic fibroblastic growth factor (bFGF), which further enhances angiogenic activity. Very little information on the expression of VEGF, bFGF, and the receptors Flt-1 and FLK/KDR is available. Herein, we evaluate the expression of these angiogenic factors and receptors in normal prostate, high grade prostate intraepithelial neoplasia (HGPIN) and prostatic cancer (CaP).

MATERIALS AND METHODS

58 selected surgical specimens exhibiting areas of normal prostate, HGPIN, and CaP were evaluated for microvessel density, and for VEGF, bFGF, Flt-1 and FLK/KDR protein expression by immunohistochemistry. Results were correlated with pathological data.

RESULTS

There was a statistically significant increase in the microvessel density and in the expression of the angiogenic factors VEGF, bFGF and the receptors FLK/KDR and Flt-1, in the premalignant and malignant tissues in comparison with normal prostatic glands. Microvessel density also correlated with higher Gleason grade, pathological stage and the expression of the receptors FLK/KDR and Flt-1.

CONCLUSIONS

The "initiation switch" of angiogenesis was observed to be an early event consistent with the recruitment of new vasculature into high grade PIN lesions and it increased in the progression of prostatic cancer.

Histological characterization and in situ localization of apoptosis in the pig follicular atresia

The aim of this study is the histological characterization of the atretic process of follicles in pig ovary. Two mechanisms have been found. In the atretic preantral follicles changes are produced in the oocyte, in the granulosa cells, an in the newly formed theca. Three histological phases can be distinguished during atresia in preantral follicles. The principal observed modification is the loss of the connections among granulosa cells that acquire a star-shaped aspect. Few apoptotic cells were observed. In the atretic antral follicles four histological phases were characterized. The presence of apoptotic cells increases progressively in the first three. A peculiar distribution of apoptotic cells in the granulosa as well as in the theca were observed in all phases.

IN CONCLUSION

A) During atresia of antral follicles in porcine many apoptotic cells were observed in the granulosa and in the theca. B) Very few apoptotic cells were found during atresia in the preantral follicles. The possible existence of some other cell death mechanism different from apoptosis which may participate in the atresia of this type of follicles is proposed.

A light microscopy and ultrastructural study of the testes of tortoise Testudo graeca (Testudinidae)

Adult males of Testudo graeca were used to preliminarily study the light microscopic morphology and the ultrastructure of the testes. Spermiogenesis has shown the presence of some interspecific variations among Chelonia, while the general features of the testes and spermatocytes are morphologically similar to other reptilians. The male reproductive state observed in the months analysed has shown spermatogenesis recrudescence in spring, a complete germinal series in autumn and testicular regression in winter. The observation of ultrastructural features, characteristic of steroidogenic activity, suggests a synchrony in tubular and interstitial compartments in T. graeca, with little steroidogenic activity in winter and active synthesis in spring and autumn. In conclusion, the results of this histological study suggest a probable asynchrony between the male and female reproductive cycle in this species and show synchrony in the steroidogenic activity of Sertoli and Leydig cells.

Morphological and morphometric study of early changes in the ageing golden hamster testis

The histological and morphometric features of the aged golden hamster testis were examined and compared with those of adult animals. Three age groups (6, 12 and 18 months) were studied by light microscopy, and testosterone levels were determined. The observations showed a progressive involution of the seminiferous tubules, beginning to be perceptible at 12 months with slight hypospermatogenesis and desquamation. In 18-month-old specimens degeneration was more significant and histopathological lesions could be classified on a 6-point scale, ranging from slight hypospermatogenesis to absence of germ cells. These involutive changes were not homogeneously distributed in the testis; affected tubules close to seeming normal ones were present. The morphometric results point to a progressive diminution, in the 3 age groups, in vas deferens spermatozoa, pachytene spermatocytes, and Sertoli and Leydig cells (the latter significantly diminished only in the 18-month-old group). For morphometric purposes a 7-point scale of tubule degeneration was used, showing a significant increase, with age, in the presence of more degenerated tubule stages. Several correlations were found between the morphometric variables, outlining existing relations between age and the associated diminution of several testis cell types, and lumen diameter. No significant differences were found between groups in serum testosterone levels. In conclusion, histological changes related to age are evident in 18-month-old animals, while at 12 months a diminution in germ cell numbers and sperm production is detectable.

Histochemical study of glycoconjugates in the epididymis of the hamster (Mesocricetus auratus)

The glycoconjugates of hamster epididymis were investigated with conventional and lectin histochemistry. A zone of the caput epididymis, with particular histochemical characteristics, has been differentiated. beta-Elimination in combination with lectins was used to establish the presence and distribution of N- and O-linked glycoconjugates. The epithelium, spermatozoa and the intertubular matrix were rich in glycoconjugates. The Golgi apparatus and stereocilia of the principal cells were intensely positive with HPA, PNA and SBA lectins. beta-Elimination indicated that these cells contained abundant O-linked glycoconjugates. Apical and clear cells presented a common lectin affinity; their reactivities towards WGA and UEA-I were very positive. These cells probably contain abundant N-glycoconjugates. The spermatozoa were stained by periodic acid-Schiff (PAS) and by all the lectins (especially in the acrosome), except by those with an affinity for alpha-L-fucosyl residues; the most intense reaction was found with HPA, WGA, PNA and SBA. Changes in the sperm lectin binding along the ductus were observed: sperm flagellum abruptly acquired WGA and PNA labelling from the posterior caput, and HPA reactivity was negative only in the zone between the caput and the corpus.

Abnormal spermatozoa in the cauda epididymidis of adult and aged hamsters (Mesocricetus auratus): a study by electron microscopy

The morphology of the spermatozoa in the cauda epididymidis of 6- and 24-month-old (adult and aged) hamster was studied by electron microscopy. Lesions found in the spermatozoa included alterations in the acrosomal matrix and nuclear membranes, abnormal or absent mitochondria, alterations in the axonemes, dense fibres and microtubules, and bent flagella. All these abnormalities are similar to those found in other species and few alterations were exclusive to the older animals. Ultrastructurally abnormal spermatozoa were observed in both groups but were present at a significantly greater frequency in aged hamsters (p < 0.005). the percentage of sperm with abnormal acrosomes, mitochondria and dense fibres and of bent (but not disrupted) spermatozoa was significantly greater in the older animals. These results show that the ultrastructural alterations in hamster sperm are similar to those found in other mammals. Moreover, the percentage of ultrastructurally abnormal spermatozoa in aged hamsters is greater than 6-month-old hamsters, this increase is not accompanied by any new kinds of alteration.

Chronic pain in the spinal cord injured: statistical approach and pharmacological treatment

We include in this article the results of a postal inquiry into chronic pain in SCI patients in Valencia (Spain), and our experience with their management. A mailed questionnaire including lesion and chronic pain data was sent to all of the 380 SCI patients who live in the region of Valencia. We received 202 answers, with 145 questionnaires being accurately answered and these were analysed for this study. The results show that chronic pain (that is, lasting more than 6 months) is very common (65.5%). The most frequent type was deafferentation pain (phantom pain), described as burning or a painful numbness. Since 1988 we have been treating a sample of 33 patients suffering from resistant pain according to the following therapies: 1 amitriptyline + clonazepam+NSAID (nonsteroidal antiinflammatory drugs); 2 amitriptyline + clonazepam + 5-OH-tryptophane + TENS (transcutaneous electrical nerve stimulation); 3 amitriptyline + clonazepam + SCS (spinal cord stimulation); 4 morphine, by continuous intrathecal infusion. After almost 4 years using these therapies we can affirm that the results regarding analgesia reached 80% in all cases, and that morphine used by intrathecal route is very safe and useful in selected patients.