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.

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.

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.

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.

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.

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).

Prevalence of exercise-induced left ventricular outflow tract obstruction in symptomatic patients with non-obstructive hypertrophic cardiomyopathy.

BACKGROUND: Resting left ventricular outflow tract obstruction (LVOTO) occurs in 25% of patients with hypertrophic cardiomyopathy (HCM) and is an important cause of symptoms and disease progression. The prevalence and clinical significance of exercise induced LVOTO in patients with symptomatic non-obstructive HCM is uncertain. METHODS AND RESULTS: 87 symptomatic patients (43.3 (13.7) years, 67.8% males) with HCM and no previously documented LVOTO (defined as a gradient >or=30 mm Hg) underwent echocardiography during upright cardiopulmonary exercise testing: 54 patients (62.1%; 95% CI 51.5 to 71.6) developed LVOTO during exercise (latent LVOTO); 33 (37.9%; 95% CI 28.4 to 48.5) had neither resting nor exercise LVOTO (non-obstructive). Patients with latent LVOTO were more likely to have systolic anterior motion of the mitral valve (SAM) at rest (relative risk 2.1, 95% CI 1.2 to 3.8; p = 0.01), and higher peak oxygen consumption (mean difference: 10.3%, 95% CI 2.1 to 18.5; p = 0.02) than patients with non-obstructive HCM. The only independent predictors of Delta gradient during exercise were a history of presyncope/syncope, incomplete/complete SAM at rest and Wigle score (all p<0.05). Subsequent invasive reduction of LVOTO in 10 patients with latent obstruction and drug refractory symptoms resulted in improved functional class and less syncope/presyncope (all p<0.05). CONCLUSIONS: Approximately two-thirds of patients with symptomatic non-obstructive HCM have latent LVOTO. This study suggests that all patients with symptomatic non-obstructive HCM should have exercise stress echocardiography.

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.

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.

Coronary microvascular dysfunction in male patients with Anderson-Fabry disease and the effect of treatment with alpha galactosidase A.

OBJECTIVE: To measure coronary flow reserve (CFR), an index of microvascular function, in Anderson-Fabry disease (AFD) at baseline and after enzyme replacement therapy (ERT). METHODS AND RESULTS: Mean (SD) myocardial blood flow (MBF) at rest and during hyperaemia (adenosine 140 microg/kg/min) was measured in 10 male, non-smoking patients (53.8 (10.9) years, cholesterol 5.5 (1.3) mmol/l) and in 24 age matched male, non-smoking controls (52.0 (7.6) years, cholesterol 4.5 (0.6) mmol/l) by positron emission tomography (PET). Resting and hyperaemic MBF and CFR (hyperaemic/resting MBF) were reduced in patients compared with controls (0.99 (0.17) v 1.17 (0.25) ml/g/min, p < 0.05; 1.37 (0.32) v 3.44 (0.78) ml/g/min, p < 0.0001; and 1.41 (0.39) v 3.03 (0.85), p < 0.0001, respectively). This coronary microvascular dysfunction was independent of cholesterol concentrations. PET was repeated in five patients after 10.1 (2.3) months of ERT; resting and hyperaemic MBF and CFR were unchanged after ERT (0.99 (0.16) v 0.99 (0.16) ml/g/min; 1.56 (0.29) v 1.71 (0.3) ml/g/min; and 1.6 (0.37) v 1.74 (0.28), respectively; all not significant). CONCLUSIONS: The results of the present study show that patients with AFD have very abnormal coronary microvascular function. These preliminary data suggest that ERT has no effect on coronary microvascular dysfunction. Further work is necessary to determine whether treatment at an earlier stage in the course of the disease may improve coronary microvascular function in patients with AFD.

Dobutamine stress echocardiography and cardiac troponin T for the detection of significant coronary artery disease and predicting outcome in renal transplant candidates.

AIMS: Ischaemic heart disease is the leading cause of mortality and morbidity in patients with end-stage renal disease (ESRD) and after renal transplantation. However, the optimal non-invasive test for coronary artery disease (CAD) diagnosis in this population has yet to be established. The aim of this study was to assess the diagnostic accuracy of dobutamine stress echocardiography (DSE) and baseline plasma cardiac troponin T (cTnT) for detecting significant CAD and predicting adverse cardiac events in patients referred for renal transplantation. METHODS: Coronary angiography, DSE, and baseline cTnT measurements were performed in 118 consecutive patients (mean age 52+/-12 years, 75 male) with ESRD (mean creatinine 608+/-272 micromol/L) referred for renal transplantation. The mean follow-up period was 1.32+/-0.48 years. Significant CAD was defined as a reduction in luminal diameter >70% by visual estimation in at least one major epicardial vessel. An abnormal DSE result defined as the development of a new regional wall motion abnormality in one or more normal resting segments or a deterioration of wall motion in one or more resting hypokinetic segments. A baseline cTnT>0.1 microg/L was taken as positive. RESULTS: Significant CAD in at least one vessel was present in 35 patients (30%). The number of patients with significant 3 vessel and 2 vessel disease was 6 and 7, respectively. An abnormal DSE result was present in 36 (31%) patients. Thirty-one (26%) had cTnT>0.1 microg/L. Sixty-four (54%) patients were on dialysis and 46 (39%) were diabetic. The sensitivity, specificity, positive and negative predictive values for DSE in detecting significant coronary artery disease were 88%, 94%, 86% and 95%, respectively. The same values for a raised cTnT were 54%, 62%, 40% and 74%, respectively. The combination of an abnormal DSE result and raised cTnT gave values of 61%, 91%, 76%, and 80%, respectively. Over the follow-up period, mortality was significantly higher in those with a raised baseline cTnT but not those with an abnormal DSE result or significant CAD. CONCLUSION: DSE is an accurate technique for the detection of significant CAD in renal transplant candidates. An elevated cTnT does not predict significant CAD in this population and when used in conjunction with DSE, reduces the sensitivity of the combined tests. cTnT is an important marker of prognosis in renal transplant candidates.

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.

Anesthesia for thoracoscopy.

Thoracoscopy has become a widely used method of achieving minimally invasive thoracic surgery. The anesthesiologist providing perioperative care for VATS is challenged to evaluate the patient carefully; to design a safe anesthetic regimen, taking into account preexisting disorders; to ameliorate physiologic alterations associated with one-lung ventilation and CO2 insufflation; and to provide safe, effective perioperative anesthesia and postoperative pain control.