Metformin pretreatment potentiates the antiproliferative action of doxorubicin against breast cancer.

OBJECTIVES: The present study aimed to evaluate the effect of metformin pretreatment on the potentiation of antiproliferative action of doxorubicin against breast cancer. MATERIAL AND METHODS: Female Wistar rats were administered with 7,12-Dimethylbenz(a)anthracene (DMBA) (35mg) in 1mL olive oil subcutaneously beneath the mammary gland. Animals were pretreated with metformin (Met) 200mg/kg two weeks before DMBA administration. DMBA control groups received doxorubicin (Dox) (4mg/kg and 2mg/kg), Met (200mg/kg) alone and in combination with Dox (4mg/kg). Met pre-treated DMBA control groups received Dox 4mg/kg and 2mg/kg. RESULTS: Met pre-treated groups treated with Dox exhibited a decrease in tumor incidence, tumor volume and increased survival rate than the DMBA group. Organ-to-body weight ratios and histopathology of heart, liver and lungs of Met pre-treated groups treated with Dox showed lesser toxicity than Dox treated DMBA control groups. There was a noteworthy decrease in malondialdehyde levels and a substantial increase in the levels of reduced glutathione together with a significant decrease in the levels of inflammatory markers like IL-6, IL-1ß and NF-κB in Met pre-treated groups treated with Dox. Histopathology of breast tumors revealed better control of tumors in Met pre-treated groups treated with Dox than DMBA control group. Immunohistochemistry and real-time PCR data revealed a significant reduction in Ki67 expression in Met pre-treated groups treated with Dox as compared to the DMBA control group. CONCLUSION: The present study suggests that metformin pretreatment potentiates the antiproliferative action of doxorubicin against breast cancer.

Correction to: Development of a sensitive PCR-dot blot assay to supplement serological tests for diagnosing Lyme disease.

In the original version of this article, the word "flagellin" is not correct. The correct word should be "P66" throughout the body of the article.

Development of a sensitive PCR-dot blot assay to supplement serological tests for diagnosing Lyme disease.

Laboratory diagnosis of Lyme disease is difficult and presently dependent on detecting Borrelia burgdorferi-specific antibodies in patient serum with the disadvantage that the immune response to B. burgdorferi can be weak or variable, or alternatively, the slow and inefficient culture confirmation of B. burgdorferi. PCR tests have previously shown poor sensitivity and are not routinely used for diagnosis. We developed a sensitive and specific Lyme Multiplex PCR-dot blot assay (LM-PCR assay) applicable to blood and urine samples to supplement western blot (WB) serological tests for detecting B. burgdorferi infection. The LM-PCR assay utilizes specific DNA hybridization to purify B. burgdorferi DNA followed by PCR amplification of p66 [corrected] and OspA gene fragments and their detection by southern dot blots. Results of the assay on 107 and 402 clinical samples from patients with suspected Lyme disease from Houston, Texas or received at the IGeneX laboratory in Palo Alto, California, respectively, were analyzed together with WB findings. The LM-PCR assay was highly specific for B. burgdorferi. In the Texas samples, 23 (21.5%) patients antibody-negative in WB assays by current US Centers for Disease Control (CDC) recommended criteria were positive by LM-PCR performed on urine, serum or whole blood samples. With IGeneX samples, of the 402 LM-PCR positive blood samples, only 70 met the CDC criteria for positive WBs, while 236 met IGeneX criteria for positive WB. Use of the LM-PCR assay and optimization of current CDC serological criteria can improve the diagnosis of Lyme disease.

Supramolecular structures fabricated through the epitaxial growth of semiconducting poly(3-hexylthiophene) on carbon nanotubes as building blocks of nanoscale electronics.

Semiconducting conjugated polymers such as (3-hexylthiophene) (P3HT) and carbon nanotubes are attractive for applications that include field-effect transistors and photovoltaic devices. In these applications, the control of structure, morphology, and alignment of polymer chains is important from the perspective of charge transport and optical properties. In this regard, a novel solution-based nucleation approach involving direct epitaxial nucleation of nanofibers of the poly(3-hexylthiophene) (P3HT) polymer on carbon nanotubes (CNTs) leading to supramolecular structure is demonstrated. The supramolecular structure of P3HT on CNTs is characterized by nucleation of oriented precursors of P3HT on CNTs by an epitaxial mechanism, onto which high density transcrystalline ∼800-1000 nm long nanofibrils of P3HT with a thickness of ∼2-3 nm are nucleated in a periodic manner. The nanoscale structure of epitaxially grown P3HT nanofibrils exhibits optical and photoluminescence characteristics. The UV-vis spectroscopy study of the fabricated structure suggests a combination of π-π electronic transition and a strong lattice vibration in the conjugated polymer chains. Furthermore, the supramolecular structure is envisaged to comprise an accumulating thread for charge transport, onto which nanometer thick long fibrils are assembled in a periodic configuration with strong potential for organic-inorganic optoelectronic devices. In conclusion, the described approach enables fabrication of supramolecular structure on carbon nanotube-based electrodes, making it attractive for functional devices.

Hearing Efficiency in Oral Submucous Fibrosis: A Clinical Study.

Oral Submucous fibrosis (OSMF) is a chronic insidious disease of oral mucosa that occurs due to areca-nut chewing, consumption of chillies, autoimmunity and genetic predisposition. The disease starts with burning sensation and inability to tolerate spicy foods with gradual reduction in mouth opening due to fibrosis of the oral mucosa. The extension of fibrosis into the naso pharynx leads to reduction in hearing efficiency. As very few studies had been done to evaluate the hearing disability in OSMF patients, this study had been undertaken to prove the same. To evaluate hearing efficiency in patients with Oral Submucous Fibrosis of various grades of severity. Presentation includes 30 patients of osmf with various grades and evaluated for hearing efficacy by audiometry. Hearing threshold was compared in different grades of osmf. The present study revealed a significant association between OSMF and hearing deficit. Involvement of the palatal muscles with OSMF may decrease the patency of the Eustachian tube, leading to conductive hearing loss. Therefore, the protocol for managing OSMF patients should include ENT consultation and treatment for hearing deficit in order to increase the success rate of treatment.

Acinetobacter infections: a retrospective study to determine inhospital mortality rate and clinical factors associated with mortality.

A retrospective case series of acinetobacter infections at a tertiary hospital in Nairobi was conducted to determine the mortality rate and factors associated with mortality. Over an eight-year period, 80 clinically significant infections were identified. The majority of infections were ventilator-associated pneumonia (40%) and bloodstream infections (30%). Eighty-six percent of the isolates were multi-drug resistant. The mortality rate in the study cohort was 45%. Twelve patients grew Acinetobacter spp. within 48 h of hospitalization, and three of these patients had no prior healthcare contact. The mean Sequential Organ Failure Assessment score was associated with mortality from acinetobacter infections.

Extracellular matrix turnover and disease severity in Anderson-Fabry disease.

BACKGROUND: Anderson-Fabry Disease (AFD) is an inherited metabolic disease associated with premature death secondary to cardiovascular and renal disease. Patients with AFD develop progressive left ventricular (LV) remodelling and heart failure. We hypothesized that altered extracellular matrix (ECM) turnover contributes to the pathophysiology of cardiac disease in AFD. METHODS AND RESULTS: Twenty-nine consecutive patients (44.1 +/- 11.7 years, 15 male) with AFD and 21 normal controls (39.7 +/- 11.3 years, 10 male) had serum analysed for matrix metalloproteinase-9 (MMP-9), and tissue inhibitor of matrix metalloproteinase-1 and -2 (TIMP-1, TIMP-2). All patients underwent clinical assessment, echocardiography and Mainz Severity Score Index (MSSI) measurement, a validated severity score in AFD. MMP-9 levels were significantly higher in patients than controls (1003.8 +/- 337.8 ng/ml vs 576.7 +/- 276.3 ng/ml respectively, p < 0.001). There were no differences in TIMP levels between patients and controls. There was a positive correlation between MMP-9 levels and MSSI (r = 0.5, p = 0.01). There was a negative correlation between MMP-9 and endocardial fractional shortening (FS) (r = -0.5, p = 0.01) and mid-wall FS (r = -0.6, p = 0.001). There was no correlation between other echocardiographic parameters and MMP-9 levels. These relations were independent of age and sex using stepwise linear regression analysis. CONCLUSIONS: Patients with AFD have abnormal ECM turnover compared to normal controls. The correlation between MMP-9 levels and systolic function suggests that altered ECM turnover is important in cardiac remodelling. The association between MMP-9 and overall disease severity suggests that circulating levels of MMP-9 may provide a useful marker for assessing the response of patients with AFD to enzyme replacement treatment.

Molecular alterations in oral carcinogenesis: significant risk predictors in malignant transformation and tumor progression.

In this study an attempt was made to establish the significance of a battery of molecular alterations and thereby identify risk predictors in oral carcinogenesis. For this purpose, EGFR, Stat3, H-ras, c-myc, p53, cyclin D1, p16, Rb, Ki-67 and Bcl-2 were localized immunohistochemically in normal mucosa (n=12), hyperplasia (n=35), dysplasia (n=25), early stage carcinoma (n=65) and advanced stage carcinoma (n=70). Deregulation occurred at an early stage and the number of alterations increased with disease progression. Using multivariate logistic regression analysis, the significant risk predictor for hyperplasia from normal mucosa was Ki-67 (OR=5.75, p=0.021); the significant risk predictors for dysplasia from hyperplasia were EGFR (OR=12.96, p=0.002), Stat3 (OR=17.16, p=0.0001), p16 (OR=5.50, p=0.039) and c-myc (OR=5.99, p=0.052); the significant risk predictors for early stage carcinoma from dysplasia were p53 (OR=6.63, p=0.0001) and Rb (OR=3.81, p=0.056); and the significant risk predictors for further progression were EGFR (OR=5.50, p=0.0001), Stat3 (OR=4.49, p=0.0001), H-ras (OR=4.05, p=0.001) and c-myc (OR=2.99, p=0.015). Cyclin D1 holds a key position linking upstream signaling pathways to cell cycle regulation. Gene products of the mitogenic signaling pathway play an equally significant role as cell cycle regulatory proteins in the hyperplasia-dysplasia-early-advanced-carcinoma sequence and together may provide a reference panel of markers for use in defining premalignant lesions and predicting the risk of malignant transformation and tumor progression.

Fabry disease and the heart: an overview of the natural history and the effect of enzyme replacement therapy.

UNLABELLED: Fabry disease is a genetic disorder caused by the deficiency of alpha-galactosidase A, resulting in the lysosomal accumulation of glycosphingolipids. Fabry disease may result in cardiac, cerebral and renal complications. Cardiac abnormalities in patients with Fabry disease were first described in the 1960s. In the 1990s a form of Fabry disease confined to the heart was reported; however, this variant is extremely rare and a more appropriate concept is of cardiac predominance of the disease in some patients. Up to 60% of males with classic Fabry disease have cardiac abnormalities, including left ventricular hypertrophy, valvular dysfunction and conduction abnormalities. Recent data suggest that left ventricular mass and systolic function in patients with Fabry disease improve after 12 months of enzyme replacement therapy (ERT); however, many of the patients studied are relatively young and have mild cardiac abnormalities, suggesting that more research into the efficacy of ERT in older patients is necessary. CONCLUSION: Cardiac manifestations are common in patients with Fabry disease and are not confined to a 'cardiac variant' of the disease.

Characterization of a ribosomal DNA clone of Brugia malayi.

The structure of ribosomal DNA (rDNA) clone pBmr7 from microfilariae of the human parasite Brugia malayi has been examined in detail by Southern blot analysis and S-1 mapping techniques. The results demonstrate that this clone contains regions homologous to 28S, 18S and 5.8S rDNAs. A noncoding or 'spacer' region lies between the 3' end of 28S rDNA and the 5' end of 18S rDNA. An AccI-Sau3AI fragment of approximately 900 bp from this spacer region cross-hybridizes to genomic DNA fragments of different sizes from Brugia pahangi and Dirofilaria immitis. The differences observed in hybridization suggest that this rDNA fragment can be used to differentiate between various filariid species.

The 5' flanking sequence of a Trypanosoma brucei variable surface glycoprotein gene.

The mechanism controlling transcription at several telomeric expression sites for variable surface glycoprotein (VSG) genes in Trypanosoma brucei is unknown. Most VSG genes in expression sites have a region 5' of the gene lacking restriction enzyme sites. This 'barren region' is involved in recombination events which replace the VSG gene with a copy of a different, non-telomeric, VSG gene leading to a switch in VSG expression. Alterations in the barren region have been considered as possible modulators of expression of the adjacent VSG gene in other switching events where no gene replacement occurs. The expressed copy of the ILTat 1.3 VSG gene remains in its expression site, on a 160 kilobase (kb) chromosome, in trypanosomes not expressing the ILTat 1.3 VSG. Here we report the complete sequence of the barren region adjacent to this gene, determined both from trypanosomes expressing the gene and from those that are not. The sequence is identical whether or not the ILTat 1.3 VSG gene is expressed. This confirms that alterations in the barren region are not involved in modulation of expression of the gene, as suggested by restriction enzyme mapping. Sequence data from the 5' flanking region of a second telomeric gene copy on an 80 kb minichromosome, and from the ILTat 1.3 expression site after replacement of the ILTat 1.3 gene by another gene from a minichromosome, provide evidence that telomeric VSG genes on minichromosomes are also flanked by long repeat arrays, and that these arrays are involved in inter-telomeric gene replacements as well as replacements by non-telomeric genes.

Characterization of an Onchocerca-specific DNA clone from Onchocerca volvulus.

A genomic library of a savanna isolate of Onchocerca volvulus was screened to detect recombinant plasmids containing highly repeated DNA sequences of this parasite. Four recombinant plasmids were identified which hybridized specifically to Onchocerca DNA, but not to DNA from humans, black flies, Brugia malayi, B. pahangi, or Wuchereria bancrofti. The recombinant plasmids had a low level of homology to Dirofilaria immitis. All recombinant plasmids contain related DNA sequences based on Southern hybridization analysis. Sequences related to these recombinant plasmids are present in different geographic isolates of O. volvulus and O. ochengi, an animal parasite. Two of the recombinant plasmids contain sequences also found in O. lienalis. One recombinant plasmid, puOvs3, has been characterized in detail, including DNA sequence determination. Radiolabeled puOvs3 is able to detect 100 pg of genomic DNA isolated from O. volvulus worms from both savanna and forest regions. It can differentiate O. volvulus from O. ochengi by Southern blot analysis.

The distribution of surface strain in the cadaveric lumbar spine.

The fourth lumbar vertebrae and L4-5 discs from six cadaveric lumbar spines were subjected to detailed strain gauge analysis under conditions of controlled loading. With central compression loads, maximal compressive strain was found to occur near the bases of the pedicles and on both superficial and deep surfaces of the pars interarticularis, which emphasises the importance of the posterior elements of lumbar vertebrae in transmitting load. Radial bulge and tangential strain of the disc wall were maximal at the posterolateral surface, in agreement with the fact that disc degeneration and prolapse commonly occur there. Under posterior offset loads simulating extension, both compressive and tensile strains were found to be increased on both surfaces of the pars interarticularis, which suggests that hyperextension may lead to stress fractures and spondylolisthesis. Posterior offset loads also increased the radial bulge of the posterior disc wall and tangential strain at the anterior surface of the disc. Anterior offset loads simulating flexion increased the radial bulge of the anterior disc wall and tangential strain at the posterior surface of the disc. These findings are compatible with movement of the nucleus pulposus within the disc during flexion and extension. This hypothesis was supported by post-mortem discography.

Age estimation by using dental radiographs.

BACKGROUND: Estimation of age is important in forensic sciences as a way to establish the identity of human remains. Of the various parts of the body used in age estimation, teeth are the least affected by the taphonomic process. Their durability means that they are sometimes the only body part available for study. Several methods of age estimation have been studied using bone and teeth, and among them, tooth wear and apposition of secondary dentine are the currently available non-destructive methods. OBJECTIVES: The purpose of the study was to determine the age of adults by using Kvaal's method as well as to establish the relationship of chronological age and dental age with its reliability and limitations on digital panoramic radiographs. MATERIALS AND METHODS: The present study was based on panoramic radiographs that consisted of two groups. One hundred orthopantomographs with Kvaal's criteria (Group A) and 50 orthopantomographs without Kvaal's criteria (Group B) were included. Various parameters were measured and the result was analyzed by means of SPSS-12.0 program statistical data. RESULT AND CONCLUSION: On the basis of Kvaal's criteria, the difference between chronological age and real age was 8.3 years. This suggests that the accuracy of this method depends on the precision of measurements and quality and number of the orthopantomographs.

Stability-indicating HPLC Method for Simultaneous Determination of Montelukast and Fexofenadine Hydrochloride.

A simple, specific, accurate, and stability-indicating reversed-phase high-performance liquid chromatographic method was developed for the simultaneous determination of montelukast and fexofenadine hydrochloride, using a Lichrospher(®) 100, RP-18e column and a mobile phase composed of methanol:0.1% o-phosphoric acid (90:10 v/v), pH 6.8. The retention times of montelukast and fexofenadine hydrochloride were found to be 10.16 and 12.03 min, respectively. Linearity was established for montelukast and fexofenadine hydrochloride in the range of 2-10 µg/ml and 24-120 µg/ml, respectively. The percentage recoveries of montelukast and fexofenadine hydrochloride were found to be in the range of 99.09 and 99.81%, respectively. Both the drugs were subjected to acid and base hydrolysis, oxidation, photolytic, and thermal degradation conditions. The degradation products of montelukast and fexofenadine hydrochloride were well resolved from the pure drug with significant differences in their retention time values. This method can be successfully employed for simultaneous quantitative analysis of montelukast and fexofenadine hydrochloride in bulk drugs and formulations.

Structure-process-functional property relationship of nanostructured carbon mediated cellular response for soft-tissue reconstruction and replacement.

The flexible and ductile silicone is widely used as a soft-tissue substitute for joint reconstruction and replacement in situations including joint pain and loss of mobility caused by the congenital or acquired factors such as osteoarthritis. Although these artificial devices have an expected life span of 15 years or more, they can fragment prematurely. Explanations for such failure are low tensile strength and inadequate bone build-up around the device, as a result of which the device does not bind with the surrounding tissues. Thus, the continued challenge for materials in contact with the bone is the design of high-strength-at-break silicone with the ability to modulate cell-substrate interactions for promoting osseointegration and long-term stability. To this end, we have discovered exciting evidence that the introduction of a novel nanostructured carbon in the void space between the silicone chains combined with processing at elevated pressure favorably stimulate cellular functions and provide a high degree of cytocompatibility. Furthermore, the high strength-at-break and undiminished intrinsic elongation of silicone are retained. In this regard, we combine here materials science and engineering and cellular biology, to elucidate the mechanism of cell-substrate interactions and the molecular machinery controlling the cell response. This is accomplished by investigating cell attachment, proliferation, and morphology, including cytomorphometric evaluation and quantitative assessment of prominent proteins, actin, vinculin, and fibronectin that are sensitive to cell-substrate interactions. The study strengthens the foundation for utilizing the nano- or quantum-size effects of nanostructured biomaterials.

A new family of folate-decorated and carbon nanotube-mediated drug delivery system: synthesis and drug delivery response.

We describe here a new family of folate-decorated and carbon nanotube (CNT)-mediated drug delivery system that involves uniquely combining carbon nanotubes with anticancer drug (doxorubicin) for controlled drug release, which is gaining significant attention. The synthesis of nanocarrier involved attachment of doxorubicin (DOX) to CNT surface via π-π stacking interaction, followed by encapsulation of CNTs with folic acid-conjugated chitosan. The π-π stacking interaction, ascribed as a non-covalent type of functionalization, allows controlled release of drug. Furthermore, encapsulation of CNTs enhances the stability of the nanocarrier in aqueous medium because of the hydrophilicity and cationic charge of chitosan. The unique integration of drug targeting and visualization has high potential to address the current challenges in cancer therapy. Thus, it is attractive to consider the possibility of investigating a drug delivery system that combines the biodegradable chitosan and carbon nanotubes (CNTs).

Structure-process-property relationship of the polar graphene oxide-mediated cellular response and stimulated growth of osteoblasts on hybrid chitosan network structure nanocomposite scaffolds.

We here describe the structure-process-property relationship of graphene oxide-mediated proliferation and growth of osteoblasts in conjunction with the physico-chemical, mechanical, and structural properties. Chitosan-graphene network structure scaffolds were synthesized by covalent linkage of the carboxyl groups of graphene oxide with the amine groups of chitosan. The negatively charged graphene oxide in chitosan scaffolds was an important physico-chemical factor influencing cell-scaffold interactions. Furthermore, it was advantageous in enhancing the biocompatibility of the scaffolds and the degradation products of the scaffolds. The high water retention ability, hydrophilic nature, and high degree of interconnectivity of the porous structure of chitosan-graphene oxide scaffolds facilitated cell attachment and proliferation and improved the stability against enzymatic degradation. The cells infiltrated and colonized the pores of the scaffolds and established cell-cell interactions. The interconnectivity of the porous structure of the scaffolds helps the flow of medium throughout the scaffold for even cell adhesion. Moreover, the seeded cells were able to infiltrate inside the pores of chitosan-graphene oxide scaffolds, suggesting that the incorporation of polar graphene oxide in scaffolds is promising for bone tissue engineering.