Metoprolol vs ivabradine in patients with mitral stenosis in sinus rhythm.

BACKGROUND: Severe mitral stenosis is usually symptomatic and is treated by BMV or surgery, whereas mild to moderate mitral stenosis is usually asymptomatic or mildly symptomatic and managed medically. Patients in the later group may become symptomatic during episodes of exercise and increased heart rate. Beta-blockers are frequently used in patients with mitral stenosis to control the heart rate and alleviate exercise-related symptoms. The objective of our study was to investigate the comparative efficacy of ivabradine versus metoprolol in patients with mitral stenosis in sinus rhythm. METHODS: We studied 97 patients of mitral stenosis in sinus rhythm presented with exertional symptoms. The effectiveness of Metoprolol was compared with ivabradine in alleviating these exertional symptoms in a randomized, open label non crossover study. We also assessed various stress ECG parameters, 24 hour Holter parameters and 2D Echo parameters to objectively compare the effects of ivabradine and metoprolol in these patients. RESULTS: Ivabradine and metoprolol both were effective in controlling exertional symptoms. Significant improvement in objective parameters like TMT (work capacity, baseline heart rate and maximal heart rate) and 2D echocardiography (right ventricular systolic pressure) are seen with both drugs. Ivabradine controls the exertional symptoms significantly more than metoprolol. On head to head comparison there was a significant benefit of working capacity and heart rate at maximal exercise in favour of ivabradine. CONCLUSIONS: Ivabradine should be strongly considered in medical management of mitral stenosis patients where beta blockers are contraindicated such as reactive airway disease. The cost of ivabradine is higher than metoprolol which might possess constraints as most of the rheumatic heat disease patients belong to low socio economic status.

Co-infection with Arsenophonus nasoniae and Orientia tsutsugamushi in a traveler.

Here we report a case of co-infection with Orientia tsutsugamushi, the causative agent of scrub typhus, and Arsenophonus nasoniae in a woman with a rash and an eschar who returned from a trip to Southeast Asia. A. nasoniae was previously considered to be a secondary insect and tick endosymbiont of unknown pathogenicity in humans. We amplified both O. tsutsugamushi and A. nasoniae DNA from a skin eschar with qPCR, and a seroconversion for O. tsutsugamushi and A. nasoniae was observed with immunofluorescence assays and western blotting for this patient. And we used 2-D western blotting with an A. nasoniae antigen and polyclonal mouse anti-A. nasoniae antibodies produced in our laboratory to detect the specific antigenic A. nasoniae proteins.

Isolation of Arsenophonus nasoniae from Ixodes ricinus ticks in Slovakia.

The tick Ixodes ricinus is the most prevalent and widely distributed tick species in Central Europe, commonly found in woodlands, heaths, and forests and particularly abundant in the Alpine region. This tick readily bites humans and transmits a number of bacterial and viral pathogens. We collected 10 live nymphs of I. ricinus ticks from vegetation in the Rovinka forest, Slovakia, and isolated a strain of Arsenophonus nasoniae from one tick using the BME/CTVM2 cell line. A new isolate was then subcultured on axenic media (Columbia agar supplemented with 5% sheep blood). To the best of our knowledge, this bacterium was never previously isolated from hard ticks or identified in ticks in Europe. We amplified and sequenced the 16S rRNA, rpoB, and ftsY genes. Limited genetic characterization showed that the isolated strain is almost identical to a strain from the parasitic wasp Nasonia vitripennis. Electron microscopy revealed a typical morphology of a Gram-negative bacterium, without pili or flagellae. Its role in human and animal pathology remains to be evaluated.

Multiple tick-associated bacteria in Ixodes ricinus from Slovakia.

Eighty Ixodes ricinus ticks collected in the Rovinka forest in Slovakia were tested by real-time and routine single-step PCR for the presence of different pathogenic and endosymbiotic bacteria. No evidence of Coxiella burnetii, Diplorickettsia massiliensis, or Bartonella spp. was found. However, we identified, as the pathogenic bacteria, Anaplasma phagocytophilum in 8%, Rickettsia helvetica in 11%, Borrelia afzelii in 9%, Bo. garinii in 8%, Bo. burgdorferi sensu stricto in 5%, Bo. valaisiana in 3%, and Bo. miyamotoi in 1% of ticks. Other bacteria with unknown or suspected pathogenicity for humans were also identified: Arsenophonus nasoniae in 25%, Spiroplasma ixodetis in 3%, Candidatus Midichloria mitochondrii in 4%, Wolbachia aff. pipientis in 14%, and Ehrlichia muris in 3% of ticks. A. nasoniae was found almost exclusively in nymphs, and E. muris was only found in adult ticks. In total, 65% of ticks contained at least one species of bacteria, and 16% contained 2 or more species.

Genome sequence of Diplorickettsia massiliensis, an emerging Ixodes ricinus-associated human pathogen.

Diplorickettsia massiliensis is a gammaproteobacterium in the order Legionellales and an agent of tick-borne infection. We sequenced the genome from strain 20B, isolated from an Ixodes ricinus tick. The genome consists of a 1,727,973-bp chromosome but no plasmid and includes 2,269 protein-coding genes and 42 RNA genes, including 3 rRNA genes.

Identification of Rickettsia africae and Wolbachia sp. in Ceratophyllus garei fleas from Passerine birds migrated from Africa.

The aim of the study was to reveal new aspects of the role of flea vector taken from migratory birds by screening of specimens with molecular biological methods. A field study was done in fishponds in Slovakia. Actually, 47 fleas were collected from reed warblers (Acrocephalus scirpaceus) and their nests. DNA was extracted and analyzed for representatives of the orders Rickettsiales. A rickettsia that shares 99.7% of identity by gltA gene with Rickettsia africae was identified in Ceratophyllus garei collected from A. scirpaceus. Moreover, two Wolbachia sp. were also detected in fleas. This is the first record of R. africae and Wolbachia sp. identified so far in Central Europe in fleas collected from migratory bird returning from Africa. This molecular study extends the geographic range and vector spectrum of arthropod-borne agents.

Evaluation of clinical specimens for Rickettsia, Bartonella, Borrelia, Coxiella, Anaplasma, Franciscella and Diplorickettsia positivity using serological and molecular biology methods.

We monitored clinical samples from patients of different age groups from selected regions in Slovakia. Overall seroprevalence evaluated by immunofluorescence (IFA) using nine Bartonella, two Borrelia, six rickettsial (spotted fever and typhus group), two Coxiella, and one human granulocytic ehrlichiosis Anaplasma, Franciscella tularensis and Diplorickettsia massiliensis antigens, in rural and city populations of Slovak Republic, was found to be 32% positive for spotted fever group rickettsiae. Only five (10%) of the rickettsia-positive cases evaluated by IFA were confirmed by polymerase chain reaction. Rickettsia helvetica, Rickettsia slovaca, and Rickettsia raoultii infection appear to be prevalent in Slovakia. Furthermore, Coxiella burnetii, Borrelia and, for the first time, Bartonella elisabethae were confirmed in Slovakia.

Antibiotic susceptibility and intracellular localization of Diplorickettsia massiliensis.

Diplorickettsia massiliensis is an obligate intracellular bacterium from the Coxiellaceae family recently isolated from Ixodes ricinus ticks. The inhibitory effects of antimicrobial agents were assessed by two different methods, immunofluorescence and Gimenez staining assay. Different markers (EEA1, Lamp-1, Cathepsin D, and LysoTracker Red DND99) were used to reveal the nature of the vacuole containing the bacterium. Ciprofloxacin, levofloxacin, and rifampin had MIC values of 2 lg mL(-1). We found that 4 lg mL(-1) of Doxycycline inhibited the growth of D. massiliensis strain. Surprisingly, D. massiliensis was resistant to chloramphenicol up to the concentration of 64 lg mL(-1). We found that penicillin G, ammonium chloride, gentamycin, omeprazole, bafilomycin A1, and chloroquine were not active against D. massiliensis. Studies performed with markers EEA1, Lamp-1, Cathepsin D, and LysoTracker Red DND99 showed that D. massiliensis is localized within an acidic compartment that is not an early phagosome, but a late phagosome or a phagolysosome. Gimenez staining stays a good method that will work with a very low number of bacteria and can be used to determine the MICs of new therapeutic antibiotics precisely. The resistance profile of D. massiliensis was found to be quite unusual for intracellular Gram-negative bacterium with marked resistance to chloramphenicol. Despite of localization in acidic compartment, pH-neutralizing agents do not significantly inhibit intracellular growth of bacterium. The results of these studies prove that antibiotic resistance does not depend on pH of vacuole. This pH-related mechanism seems not to play a contributing role in the overall resistance of D. massiliensis.

Cyanobacteria cultivation in industrial wastewaters and biodiesel production from their biomass: a review.

As an alternative fuel biodiesel has become increasingly important due to diminishing petroleum reserves and adverse environmental consequences of exhaust gases from petroleum-fueled engines. Recently, research interest has focused on the production of biofuel from microalgae. Cyanobacteria appeared to be suitable candidates for cultivation in wastes and wastewaters because they produce biomass in satisfactory quantity and can be harvested relatively easily due to their size and structure. In addition, their biomass composition can be manipulated by several environmental and operational factors to produce biomass with concrete characteristics. Herein, we review the culture of cyanobacteria in wastewaters and also the potential resources that can be transformed into biodiesel successfully for meeting the ever-increasing demand for biodiesel production.

Epidemiology of infective endocarditis in Chennai, South India.

BACKGROUND: Infective endocarditis (IE) is an infection of the endocardial surface of the heart. Despite recent advances in diagnosis and treatment, mortality rates remain high. Data on the prevalence, epidemiology and etiology of IE from India are sparse. AIMS AND OBJECTIVES: The aim of this study was to evaluate the clinical, laboratory, microbiological, and echocardiographic characteristics of IE patients in Chennai, south India. MATERIALS AND METHODS: Patients were classified based on modified Duke criteria. Details of the clinical profile of the patients and laboratory data were recorded. Blood cultures were performed to establish the etiology. RESULTS: Ninety six percent of patients had native valve endocarditis. Mitral valve was the most commonly affected valve. CONCLUSION: Rheumatic heart disease was the most common predisposing factor and fever was the most common clinical feature. Viridans group streptococci accounted of the culture positive cases.

Intratumoral delivery of docetaxel enhances antitumor activity of Ad-p53 in murine head and neck cancer xenograft model.

PURPOSE: The aim of this study is to determine the ability of intratumorally delivered docetaxel to enhance the antitumor activity of adenovirus-mediated delivery of p53 (Ad-p53) in murine head and neck cancer xenograft model. MATERIALS AND METHODS: A xenograft head and neck squamous cell carcinoma mouse model was used. Mice were randomized into 4 groups of 6 mice receiving 6 weeks of biweekly intratumoral injection of (a) diluent, (b) Ad-p53 (1 x 10(10) viral particles per injection), (c) docetaxel (1 mg/kg per injection), and (d) combination of Ad-p53 (1 x 10(10) viral particles per injection) and docetaxel (1 mg/kg per injection). Tumor size, weight, toxicity, and overall and disease-free survival rates were determined. RESULTS: Intratumoral treatments with either docetaxel alone or Ad-p53 alone resulted in statistically significant antitumor activity and improved survival compared with control group. Furthermore, combined delivery of Ad-p53 and docetaxel resulted in a statistically significant reduction in tumor weight when compared to treatment with either Ad-p53 or docetaxel alone. CONCLUSION: Intratumoral delivery of docetaxel enhanced the antitumor effect of Ad-p53 in murine head and neck cancer xenograft model. The result of this preclinical in vivo study is promising and supports further clinical testing to evaluate efficacy of combined intratumoral docetaxel and Ad-p53 in treatment of head and neck cancer.

Effect of docetaxel on the surgical tumor microenvironment of head and neck cancer in murine models.

OBJECTIVES: To identify the antitumor activity and wound-healing effect of docetaxel delivered in the surgical tumor microenvironment of head and neck squamous cell carcinoma (HNSCC). DESIGN: Control and experimental series. SETTING: Academic medical center. SUBJECTS: BALB/c and severe combined immunodeficiency mice. INTERVENTION: Intrawound (IW) docetaxel therapy was tested in 3 HNSCC xenograft and 2 taxane-resistant models. Intratumoral (IT) docetaxel therapy was further tested in the 2 taxane-resistant models. MAIN OUTCOME MEASURES: Tumor size, survival, and wound toxic effects were measured. The effect of docetaxel on various factors involved in wound healing and tumor growth within the surgical tumor microenvironment was also analyzed. RESULTS: In a pilot study using BALB/c mice, IW docetaxel therapy was not associated with problems in wound healing. Using the HN6, HN12, and HN30 HNSCC xenograft model, IW docetaxel prevented tumor growth and improved survival when compared with controls. No local or systemic toxic effect or wound-healing problem was noted. Using taxane-resistant xenograft lung cancer (H460/T800) and syngeneic salivary cancer (BALB/c mucoepidermoid carcinoma) models, IW therapy did not delay tumor growth. An antitumor effect was detected with repeated docetaxel injections in the H460/T800 taxane-resistant model but not in the BALB/c mucoepidermoid carcinoma model. Docetaxel inhibited the expression of growth factors and receptors in tumor cells; however, it did not inhibit the level of wound-healing growth factors in the surgical tumor microenvironment. CONCLUSIONS: These preclinical results support further testing of IW docetaxel treatment in HNSCC. Docetaxel appears to exert antitumor activity without affecting factors involved in wound healing in the tumor microenvironment.

BMS-275183-induced gene expression patterns in head and neck carcinoma.

PURPOSE: BMS-275183 is an orally bioavailable taxane that has antitumor activity in preclinical cancer models. However, limited BMS-275183 studies have been performed in head and neck squamous cell carcinoma (HNSCC) cell lines. The purpose of this study is to identify the biological activity of BMS-275183 on HNSCC. MATERIALS AND METHODS: Head and neck squamous cell carcinoma cell lines, HN6, HN12, and HN30, were exposed to BMS-275183. BMS-275183-induced growth suppression, cell-cycle arrest, and apoptosis were measured. Then, expression of selected proteins that were induced by BMS-275183 was determined by Western blot analysis. RESULTS: BMS-275183 suppressed proliferation and induced G(2)M arrest and apoptosis in all HNSCC cell lines tested. BMS-275183 altered the expression of cell-cycle regulators, such as cyclin A and cyclin B1. The expression of E2F and p27 was decreased and increased, respectively, in all HNSCC cell lines. Cleaved caspase 3 and poly (ADP-ribose) polymerase (PARP) were increased in HN6 and HN12 cells. epidermal growth factor receptor (EGFR) and mitogen-activated protein kinase (MAPK) expression were decreased by BMS-275183 in HN6 and HN30 cell lines, whereas phosphorylated epidermal growth factor receptor (pEGFR) was decreased in only HN6 cells. CONCLUSIONS: BMS-275183 induced cellular apoptosis, cell-cycle arrest, and altered gene expression in HNSCC via molecular pathways similar to other taxanes. These preclinical experiments suggest that BMS-275183 may be useful in treating HNSCC and that the aforementioned genes can potentially be used as surrogate end-point biomarkers.

An in vivo evaluation of docetaxel delivered intratumorally in head and neck squamous cell carcinoma.

OBJECTIVE: To identify activity and biological mechanisms of intratumoral (IT) docetaxel on head and neck squamous cell carcinoma (HNSCC). METHODS: Docetaxel IT therapy was tested in xenograft models of 2 HNSCC lines, HN30 and HN12. The overall and disease-free survival rates, tumor growth, and toxic effects were measured. The pharmacokinetic profiles of docetaxel in plasma and tumor were compared after IT and intravenous (IV) administration. Comparisons between common and supradoses of docetaxel with regard to expression of regulators in the cell cycle, apoptosis, and signal transduction pathways were determined using Western blot analysis. RESULTS: In the HN30 and HN12 xenograft models, IT docetaxel improved overall as well as disease-free survival and reversed tumor growth. The only toxic effects noted were local (alopecia and skin breakdown). Skin breakdown resolved in all cases. At equivalent dosing levels, IT docetaxel achieved a 26-fold higher peak tumor concentration and 24-fold longer tumor exposure than IV treatment. Furthermore, limited plasma exposure was noted with IT docetaxel. Supradose levels of docetaxel produced distinct protein expression patterns for regulators of the cell cycle (cyclins A and B, p21, and p27), apoptosis (cleaved caspase-3 and cleaved PARP), and signal transduction (EGFR, pEGFR, pc-Jun, and pERK) in HNSCC, which supports a distinctive mechanism of action for supradose docetaxel levels. Since levels of cleaved caspase-3 and PARP, markers of apoptosis, were only elevated with lower doses, the observed cell death at supradose levels was probably due to necrosis. CONCLUSIONS: Injections of IT docetaxel at usual and supradoses are associated with a pharmacokinetic profile and biological mechanism distinct from those observed with usual IV doses. It is calculated that IT therapy in men will increase peak concentrations of docetaxel in tumors by 1000-fold over the conventional IV dose used clinically. These preclinical results support further testing of IT docetaxel in HNSCC.

Stimulus and recording variables and their effects on mammalian vestibular evoked potentials.

Linear vestibular evoked potentials (VsEPs) measure the collective neural activity of the gravity receptor organs in the inner ear that respond to linear acceleration transients. The present study examined the effects of electrode placement, analog filtering, stimulus polarity and stimulus rate on linear VsEP thresholds, latencies and amplitudes recorded from mice. Two electrode-recording montages were evaluated, rostral (forebrain) to 'mastoid' and caudal (cerebellum) to 'mastoid'. VsEP thresholds and peak latencies were identical between the two recording sites; however, peak amplitudes were larger for the caudal recording montage. VsEPs were also affected by filtering. Results suggest optimum high pass filter cutoff at 100-300 Hz, and low pass filter cutoff at 10,000 Hz. To evaluate stimulus rate, linear jerk pulses were presented at 9.2, 16, 25, 40 and 80 Hz. At 80 Hz, mean latencies were longer (0.350-0.450 ms) and mean amplitudes reduced (0.8-1.8 microV) for all response peaks. In 50% of animals, late peaks (P3, N3) disappeared at 80 Hz. The results offer options for VsEP recording protocols.