Experimental and Computational Characterization of the Interaction between Gold Nanoparticles and Polyamidoamine Dendrimers.

Dendrimers provide a means to control the synthesis of gold nanoparticles and stabilize their suspensions. However, design of improved dendrimers for this application is hindered by a lack of understanding how the dendrimers and synthesis conditions determine nanoparticle morphology and suspension stability. In the present work, we evaluate the effect of polyamidoamine (PAMAM) dendrimers terminated with different functional groups (-OH or -NH3+) and different synthesis conditions on the morphology of the resulting gold nanoparticles and their stability in solution. We leverage molecular dynamics (MD) simulations to identify the atomic interactions that underlie adsorption of PAMAM dendrimers to gold surface and how the thermodynamics of this adsorption depends on the terminal functional groups of the dendrimers. We find that gold nanoparticles formed with hydroxyl-terminated PAMAM (PAMAM-OH) rapidly aggregate, whereas those formed with PAMAM-NH3+ are stable in solution for months of storage. Synthesis under ultrasound sonication is shown to be more rapid than that under agitation, with sonication producing smaller nanoparticles. Free-energy calculations in MD simulations show that all dendrimers have a high affinity for the gold surface, although PAMAM-OH and its oxidized aldehyde form (PAMAM-CHO) have a greater affinity for the nanoparticle surface than PAMAM-NH3+. Although adsorption of PAMAM-OH and PAMAM-CHO has both favorable entropy and enthalpy, adsorption of PAMAM-NH3+ is driven by a strong enthalpic component subject to an unfavorable entropic component.

Selection of reference genes in Hedysarum coronarium under various stresses and stages of development.

The cultivation of Hedysarum coronarium has generated interest recently for its high yield as a fodder crop, its high protein content, and the presence of condensed tannins in its leaf and stem tissues. Gene expression studies can lead to a better understanding of the biological processes of live organisms. Specifically, reverse transcription followed by quantitative polymerase chain reaction (PCR) represents the most powerful technology for comparing the expression profiles of target genes. The use of reference genes as internal controls to normalize messenger RNA (mRNA) levels is a requirement of quantitative PCR (qPCR). Few studies on reference genes have been performed in plants, and no studies have been performed in H. coronarium. Therefore, the aim of this study was to identify and evaluate reference genes to use in qPCR in H. coronarium. Sulla tissues under two conditions of abiotic stress and at various stages of development were studied to determine adequate reference genes. To optimize the identity and number of reference genes, geNorm and BestKeeper software programs were employed. Based on the results of both analyses, TUA1, TUA2, and UBQ were found to be the most suitable reference genes, and the combination of these three genes was suggested for the accurate normalization of gene expression in sulla tissues.

Review of cognitive impairment with antimuscarinic agents in elderly patients with overactive bladder.

Overactive bladder (OAB) will become an increasingly prevalent problem as the proportion of older people in the population increases over the next 20 years. In addition to the urological symptoms (urinary urgency, with or without urgency incontinence, usually with increased daytime frequency and nocturia), OAB is associated with other problems in older patients, especially an increased risk of falls and fractures. The bother caused by OAB needs not be an inevitable consequence of ageing, because the symptoms can usually be alleviated, even in frail older people. Pharmacological treatment for OAB involves the use of antimuscarinic agents, whose efficacy and safety profiles depend on their interactions with muscarinic receptors that are widely distributed throughout the body. Interactions between antimuscarinics and M(1) receptors in the central nervous system may have the potential to cause cognitive impairment in older people, depending on muscarinic receptor binding profiles, lipophilicity and the ability to cross the blood brain barrier. Concerns over the possibility of cognitive impairment have contributed to an under-utilisation of antimuscarinics in the geriatric population, despite the high prevalence and severity of OAB in older subjects. Antimuscarinic agents should be actively considered for elderly patients with OAB, but it is desirable to establish the cognitive risk for every type of antimuscarinic, using robust cognition assessment methods.

Selection of housekeeping genes for normalization by real-time RT-PCR: analysis of Or-MYB1 gene expression in Orobanche ramosa development.

Real-time PCR has become the method of choice for accurate and in-depth expression studies of candidate genes. To avoid bias, real-time PCR is referred to one or several internal control genes that should not fluctuate among treatments. A need for reference genes in the parasitic plant Orobanche ramosa has emerged, and the studies in this area have not yet been evaluated. In this study, the genes 18S rRNA, Or-act1, Or-tub1, and Or-ubq1 were compared in terms of expression stability using the BestKeeper software program. Among the four common endogenous control genes, Or-act1 and Or-ubq1 were the most stable in O. ramosa samples. In parallel, a study was carried out studying the expression of the transcription factor Or-MYB1 that seemed to be implicated during preinfection stages. The normalization strategy presented here is a prerequisite to accurate real-time PCR expression profiling that, among other things, opens up the possibility of studying messenger RNA levels of low-copy-number-like transcription factors.

First Report of Orobanche crenata on Sulla (Hedysarum coronarium) in Andalusia, Southern Spain.

Crenata broomrape (Orobanche crenata Forsk.), an obligate chlorophyll-lacking root parasite, is the major constraint for growing legume crops in infested soils in southern Spain. Peas (Pisum sativum L), faba beans (Vicia faba L.), and narbon bean (Vicia narbonensis L.) are seriously affected (1,2,4). However, no information is available regarding its ability to attack sulla (Hedysarum coronarium L.), which is an important fodder legume grown in rain-fed conditions, yielding as much as 10,000 kg/ha of dry matter. In 2008, we found broomrape shoots infecting 4 to 5% of sulla plants in a trial field (two land races, P-26 and P-3, in a 500-m2 area) in Cordoba (Andalusia, southern Spain). The shoots developed numerous fertile flowering stalks throughout the field. The previous crop, narbon bean, was heavily infected during 2007 by O. crenata. Infection of sulla plants was confirmed by digging up the plant to verify the attachment of the broomrape plant to the sulla roots. The level of infection was low with only one to two emerged broomrape shoots per sulla plant infested. Morphology was typical of O. crenata. The calyx of the flowers was 13 to 18 mm long with free, bidentate segments. The white corolla of the flowers was 18 to 28 mm long and glandular pubescent. The lips were divergent, large, not ciliate, and filaments inserted 2 to 3 mm above the base of the corolla are hairy at base with glandular hair at the apex. The anthers were brown (3). Specimens were deposited in the Herbarium of the University of Córdoba (identification number COA 45358). To our knowledge, this first report of O. crenata parasitizing sulla shows that control methods for O. crenata will be needed if sulla is to be used as an alternative legume fodder in the infested soils of southern Spain. References: (1) J. I. Cubero and M. T. Moreno. Page 41 in: Some Current Research on Vicia faba in Western Europe. D. A. Bond et al., eds. Luxembourg, 1979. (2) S. Nadal et al. Plant Breed. 126:110, 2007. (3) A. J. Pujadas-Salvá. Page 187 in: Resistance to Orobanche: The State of the Art. Junta de Andalucía, Sevilla, Spain, 1999. (4) D. Rubiales et al. Crop Prot. 22:865, 2003.

Role of cell wall-degrading enzymes in pathogenicity of Fusarium oxysporum.

Fusarium oxysporum invades its host plants through the roots and colonizes the vascular system. It produces a great variety of cell-wall degrading enzymes (CWDE), such as cellulases, xylanases, pectinases and proteases. Our group has purified and characterized an endopolygalacturonase (PG1), two exopolygalacturonases (PG2 and PG3), an endoxylanase (XYL1) and an endo pectatelyase (PL1). We have isolated the following CWDE-encoding genes: pg1, pgx4, pg5, xyl2, xyl3, prt1 and pl1. Gene expression in different culture conditions has been determined by Northern analysis. The occurrence of these genes in different formae speciales has been analyzed by Southern analysis and PCR. All these genes are expressed during different stages of the interaction with the host plant indicating a possible role in pathogenesis. At present, targeted gene disruption is being carried out, in order to determine the role of each gene in the pathogenicity process.

[Massive myocardial infiltration by lymphoma of tonsilar origin simulating left ventricular hypertrophy: diagnosis using echocardiography]. / Infiltración miocárdica masiva por linfoma de origen amigdalar que simula hipertrofia ventricular izquierda: diagnóstico mediante ecocardiografía.

We present the first described case in the literature of isolated left anterior hemiblock, in the setting of massive myocardial invasion by a primary tonsilar lymphoma. Such process evolved with a morphologic pattern mimicking left ventricular hypertrophy of unequal distribution. An hemodynamic behaviour of an infiltrative cardiomyopathy, with both systolic and diastolic important ventricular dysfunction, was observed. An early presumptive diagnosis of severe lymphomatous myocardial invasion was established by echocardiography. The pathologic examination confirmed it subsequently.

[Septic thrombophlebitis of the great vessels of the neck. A severe complication of central venous catheters]. / Tromboflebitis séptica de las grandes venas del cuello. Una complicación grave de los catéteres venosos centrales.

Septic thrombophlebitis of the large veins of the neck is an uncommon, but extremely severe, complication in carriers of central venous catheters. Treatment of these cases is difficult and, generally, the clinical condition does not permit surgical approach. Four patients with septic central vein thrombophlebitis are reported. They were treated with conservative measures including catheter removal and high-dose parenteral antibiotics for at least four weeks, with excellent results in all. The relevant literature and the therapeutic alternatives are reviewed.

Plant resistance to parasitic plants: molecular approaches to an old foe.

Parasitic weeds pose severe constraint on major agricultural crops. Varying levels of resistance have been identified and exploited in the breeding programmes of several crops. However, the level of protection achieved to date is either incomplete or ephemeral. Resistance is mainly determined by the coexistence of several mechanisms controlled by multigenic and quantitative systems. Efficient control of the parasite requires a better understanding of the interaction and their associated resistance mechanisms at the histological, genetic and molecular levels. Application of postgenomic technologies and the use of model plants should improve the understanding of the plant-parasitic plant interaction and drive not only breeding programmes through either marker-assisted selection (MAS) or transgenesis but also the development of alternative methods to control the parasite. This review presents the current approaches targeting the characterization of resistance mechanisms and explores their potentiality to control parasitic plants.

[Hormone therapy, fertility and pregnancy in antiphospholipid syndrome]. / Terapias hormonales, fertilidad y embarazo en el síndrome antifosfolipídico.

Antiphospholipid syndrome (APS) carries a risk of thrombosis and infertility. Consequently the use of any type of hormone therapy and pregnancy in APS requires special considerations. The present article provides a broad review of all these issues. The use of contraception, hormone replacement therapy and selective estrogen receptor modulators in APS are described. In vitro fertilization/embryo transfer and ovarian induction in these patients are reviewed. Lastly, the possible fetal and maternal complications that can occur during pregnancy are described and, based on the literature, recommendations for the management of pregnancy in women with APS are provided.

Treatment of experimental endocarditis due to methicillin-susceptible or methicillin-resistant Staphylococcus aureus with trimethoprim-sulfamethoxazole and antibiotics that inhibit cell wall synthesis.

Using two strains of Staphylococcus aureus, one susceptible and one heterogeneously resistant to methicillin, for which MICs and MBCs of trimethoprim-sulfamethoxazole (TMP-SMX) were 0.06 and 0.06 micrograms/ml and 0.06 and 0.25 microgram/ml, respectively (concentrations are those of TMP), we studied the efficacies of TMP-SMX and cloxacillin, teicoplanin, and vancomycin for treatment of experimental staphylococcal endocarditis. Rabbits were treated with dosages of TMP-SMX selected to achieve concentrations in serum equivalent to that obtained in humans treated for Pneumocystis carinii pneumonia. The overall mortality rate of rabbits treated with TMP-SMX was 84% at day 3, not different from that of the control groups (P > 0.1). No sterile vegetations were observed to be present in control groups or in animals treated with TMP-SMX. However, 26, 60, and 75% of rabbits treated with teicoplanin, cloxacillin, and vancomycin, respectively, showed sterile vegetations. For methicillin-susceptible S. aureus (MSSA), the mean vegetation counts were not significantly different between the control group and the group treated with TMP-SMX (P > 0.1). For methicillin-resistant S. aureus (MRSA), treatment with TMP-SMX was more effective than no therapy, decreasing the number of organisms in vegetations (P < 0.01). For both strains, therapy with cloxacillin and therapy with teicoplanin or vancomycin were significantly more effective than therapy with TMP-SMX. Despite high concentrations of teicoplanin in serum which exceeded MBCs for staphylococci more than 50 times at the peak and 10 times at the trough, therapy with cloxacillin or vancomycin was superior to therapy with teicoplanin against both MSSA and MRSA. These data do not support the use of TMP-SMX in treatment of endocarditis and other severe staphylococcal infections with high bacterial counts.

Treatment of experimental endocarditis due to penicillin-resistant Streptococcus pneumoniae.

Using two strains of pneumococci for which MICs of penicillin were 1 and 4 micrograms/ml, those of cefotaxime were 0.01 and 0.5 micrograms/ml, and those of teicoplanin were 0.01 and 0.1 micrograms/ml, we studied the efficacy of different dosages of penicillin, cefotaxime, and teicoplanin in the treatment of experimental pneumococcal endocarditis in rabbits. Animals treated with dosages of penicillin G procaine needed to achieve levels in serum near the MIC for pneumococci showed a significant reduction in log10 CFU per gram of vegetation, as compared with the control (P < 0.001), although only 20% of the animals showed sterile vegetations. When levels of penicillin in serum were in the range of three- to fourfold the MIC, a greater reduction in log10 CFU per gram of vegetation was seen, and 88% of the animals showed sterile vegetations. Only the regimen of penicillin that provided concentrations in serum above the MIC throughout the interval between two doses provided constant sterilization of the cardiac vegetations. Dosages of cefotaxime and teicoplanin selected to achieve concentrations in serum equivalent to that obtained in humans during treatment resulted in levels of antimicrobial agents in serum hundreds or thousands of times higher than the MICs for the infecting strains. In terms of antimicrobial efficacy, cefotaxime and teicoplanin were equivalent to regimens with high dosages of penicillin.

Colocalization of aldehyde dehydrogenases and Fe/NADPH-induced lipid peroxidation in tissue sections of rat retina.

Epidemiological and experimental studies suggest the involvement of lipid peroxidation (LPO) in retinal diseases. Clinicians usually prescribe antioxidants to help in the treatment of proliferative diabetic vitreoretinopathy and age-related macular degeneration. In spite of this, these processes inexorably induce visual impairment and may progress towards blindness. In addition to other pathogenic mechanisms not fully understood, it may be that peroxidic aldehydes from LPO occurring in the eyes, acting as cytotoxic chemicals, mediate in these chronic disorders. To test the mechanisms of removing peroxidic aldehydes from retinal cells and in an attempt to understand long-lasting changes induced by LPO, the distribution and activity of aldehyde dehydrogenases (ALDH) in the rat retina were studied and compared with the LPO sites induced by iron/nicotine adenine dinucleotide phosphate. Histochemical and immunocytochemical assays revealed the colocalization of LPO and ALDH, mainly in the photoreceptors and inner retinal layers. This suggests the involvement of ALDH in detoxifying peroxidic aldehydes from the retina. Any change in ALDH retinal expression and distribution might be of crucial importance in assessing the paths of LPO-mediated vitreoretinopathies. Further research is needed to evaluate these findings and their application to new ophthalmic therapy.

Hospital-acquired infectious endocarditis not associated with cardiac surgery: an emerging problem.

To assess the most relevant features of hospital-acquired endocarditis, we conducted a retrospective study of cases of infectious endocarditis at a single university hospital from 1978 through 1992. During this period 248 episodes of infectious endocarditis were documented; 23 (9.3%) of these episodes were hospital-acquired and were not associated with cardiac surgery. (This figure represented a remarkable rise in the frequency of nosocomial endocarditis, only one case of which was identified among 101 cases of endocarditis treated at the same institution between 1960 and 1975.) In each of the 23 nosocomial cases, endocarditis was the result of bacteremia associated with a hospital-based procedure: intravenous catheterization (15 cases), instrumentation of a diseased urogenital tract (seven cases), or liver biopsy (one case). Staphylococcus aureus and Enterococcus faecalis were the predominant organisms isolated from intravenous catheters and the urogenital tract, respectively. Two of seven enterococcal isolates were highly resistant to gentamicin (MIC, > 2,000 micrograms/mL). Overall mortality was 56%. Two subsets of at-risk patients with different anatomic and clinical manifestations were identified. Our results emphasize that infectious endocarditis must be considered a serious nosocomial hazard against which preventive measures must be implemented.

Lipid peroxidation in proliferative vitreoretinopathies.

PURPOSE: To study the lipid hydroperoxide activity in vasoproliferative and fibroproliferative retinal disorders. METHODS: Vitreous body samples from patients undergoing vitrectomy because of proliferative vitreoretinopathy (PVR; n = 12) or proliferative diabetic retinopathy (PDR; n = 15), and rhegmatogenous retinal detachment/macular hole/epiretinal membranes as the comparison group (CG; n = 14), were analysed for protein content and basal and induced lipid peroxidation (LPO), as determined by the thiobarbituric acid reactive substances (TBARS) test and LPO 586 commercial kit. The antioxidant activity for superoxide dismutase (SOD) and catalase (CAT) was also assayed. RESULTS: Malondialdehyde (MDA)-like metabolites and 4-hydroxynonenal (4-HNE) mean values were first measured to assess basal LPO, and found to be significantly higher in the PVR and PDR cases than in the CG (p < or = 0.0001). LPO induced by nicotine adenine dinucleotide phosphate iron (NADPH-Fe) was then assayed and the data showed that MDA mean values were 5-fold greater for the PVR and PDR eyes than in the case of basal LPO (p < or = 0.0001). SOD activity was significantly smaller in the PVR (p = 0.0010) and PDR (p < or = 0.0001) groups than in the CG. CAT levels displayed significantly lower values in the PVR and PDR cases than in the CG (p < or = 0.0001). No significant differences in free radical (FR) formation and antioxidant status between PVR and PDR patients were observed. CONCLUSIONS: Fibrovascular proliferative vitreoretinopathies correlate with increased FR formation and decreased antioxidant activity in the human vitreous body.

[Fasciola hepatica infestation. Biopathology and new diagnostic and therapeutic aspects]. / Infestación por Fasciola hepatica. Biopatología y nuevos aspectos diagnósticos y terapéuticos.

We present here 6 patients with Fasciola hepatica infection, all from rural origin, and with the risk factors of eating wild watercress. The more common symptoms were: fever (83%), abdominal pain (100%), weight loss (83%) and generalized myalgia and joint pain (67%). All patients presented with an absolute eosinophil count above 1,000 cell/mm3. The diagnosis was established in five cases by means of serologic techniques (haemagglutination) and with direct visualization of adult worms while surgery in one case. A CT abdominal scan was performed in five patients, revealing specific lesions of tissue infiltration in four of them. Praziquantel was used in four patients, achieving clinical cure in three cases. In two patients, bithionol was used, with clinical cure in both cases. We review also some newer diagnostic and therapeutic approaches to this parasitic disease.

[Yellow nail syndrome: presentation of a case and review of the literature]. / Síndrome de las uñas amarillas: presentación de un caso y revisión de la literatura.

We discuss the yellow nails syndrome which is constituted by yellow nails, pleural effusion and lymphedema. After reviewing the literature, it can be said that nail disorders are an early and constant sign, and its absence could put in doubt the diagnosis of this syndrome. The most frequent pleuro-pulmonary disorder is the pleural effusion, chylous or exudative type. It is believed that the origin of this disease could be a congenital hypoplasia of the lymphatic vessels. Lymphography and the morphologic study performed show a diminution in the number and size of the lymphatics vessels (lymphedema) which are hypoplastic, varicosities and tortuous dilations are sometimes observed.

[Urinary incontinence in the elderly: clinical and urodynamic review of 195 cases]. / Incontinencia urinaria en el anciano: revisión clínica y urodinámica de 195 casos.

One hundred ninety-five male and female patients over 65 years old presenting with urinary incontinence were evaluated by clinical and urodynamics. Urinary incontinence was in the form of urgency-incontinence in 68% of the cases, incontinence at cough in 26%, and urinary incontinence which the patient referred to no specific situation in 6%. Among the different urodynamics data, bladder instability was the most common (73%). Urinary stress incontinence was observed in 35% of the cases. Bladder instability was demonstrated in 77% of the cases with urgency-incontinence and in 69% of the cases with incontinence not referred to a specific situation. All the male patients with lower urinary tract obstruction had urgency-incontinence. Stress incontinence was demonstrated in 60% of the cases with incontinence at cough. Stress incontinence was not observed in male patients without associated diseases. The associated neurological disorder was accompanied by bladder hyperreflexia in 90% of the cases. A prior adenomectomy or hysterectomy was associated with a greater number of cases with stress urinary incontinence, accounting for 62% in both males and females.

[Endocarditis caused by Staphylococcus aureus in drug addicts and non-addicts: the same microbe in 2 diseases]. / Endocarditis por Staphylococcus aureus en adictos y no adictos: un mismo microbio para dos enfermedades distintas.

46 Staphylococcus aureus endocarditis episodes diagnosed with strict criteria in non drug addict patients, and 25 episodes in drug addict patients have been comparatively analyzed. Infection was found in the left side of the heart in 87% of the non addict patients and in 16% of the addicts. On the contrary, 84% of the addicts had endocarditis of the tricuspid and pulmonary valves while only 13% of the non addicts had right heart involvement. The right side endocarditis in the non addicts was always due to intracardiac catheters. 54% of the endocarditis episodes in the non addicts were fatal. Only two addicts, both when had left side endocarditis, died. Mortality was conditioned by infection of the left side of the heart as well as by the existence of heart failure. No significant differences were found between the evolution of patients treated with only one agent or of those treated with a beta-lactam antibiotic plus gentamicin. The emergency valve replacement significantly improved the prognosis of patients with prosthetic valve endocarditis.