Metal cation toxicity in the alga Gracilaria domingensis as evaluated by the daily growth rates in synthetic seawater

Macroalgae of the genus Gracilaria have considerable economic importance as raw material for agar production and belong to an important group of organisms that are tolerant of high concentrations of metal. The median inhibitory concentration (IC₅₀) values obtained by measuring the ratio of fresh mass variation (i.e., daily growth rates) of the red macroalga Gracilaria domingensis during a 48-h aquatic toxicity assay are reported here. The alga was exposed to 14 different metal cations as well as the molybdate anion in synthetic seawater. The actual concentrations of these ionic species (at IC₅₀ values) and the proportion of free ions (aqueous complexes) were determined by inductively coupled plasma atomic emission spectroscopy and the Environmental Protection Agency-recommended software, MINTEQA2, respectively. Based on the free IC₅₀ values (IC₅₀ ^F), the ions were ranked in terms of toxicity: Cd²⁺???Cu²⁺???Pb²⁺???Zn²⁺???Ni²⁺?>?Co²⁺?>?La³⁺???Mn²⁺?>?Ca²⁺?~?Li⁺???MoO₄ ^2????Sr²⁺?>?Mg²⁺???K⁺?>?Na⁺. As a member of the first trophic level in the marine food chain, G. domingensis is an appropriate target organism both for the development of toxicological assays and as a bioindicator of marine degradation.     

Cologastric fistula with a foreign body in a patient with Crohn's disease

Although the medical management of fistulizing Crohn's disease is improving, a subset of patients does not respond to maximal medical therapy and is referred for surgical consultation. We report a case of Crohn's colitis with an ingested foreign body resulting in a cologastric fistula. The patient underwent segmental colectomy and takedown of the cologastric fistula. At the time of laparotomy, the foreign body was found in the fistulous colonic segment. The presence of an ingested foreign body likely contributed to a rare fistula that was refractory to medical management.     

Influence of culture conditions on mycelial growth and bioluminescence of Gerronema viridilucens

Herein we describe a procedure for measuring the total light emission of the naturally bioluminescent tropical fungus Gerronema viridilucens and the optimization of culture conditions using multivariate factorial anova. Cultures growing on an agar surface in 35 mm Petri dishes at 90% humidity show optimal bioluminescence emission at 25 degrees C in the presence of 1.0% sugar cane molasses, 0.10% yeast extract and pH 6.0 (nonbuffered). Temperature and pH are the most important factors for both mycelial growth and bioluminescence.     

Vision in click beetles (Coleoptera: Elateridae): pigments and spectral correspondence between visual sensitivity and species bioluminescence emission

Among lampyrids, intraspecific sexual communication is facilitated by spectral correspondence between visual sensitivity and bioluminescence emission from the single lantern in the tail. Could a similar strategy be utilized by the elaterids (click beetles), which have one ventral abdominal and two dorsal prothoracic lanterns? Spectral sensitivity [S(λ)] and bioluminescence were investigated in four Brazilian click beetle species Fulgeochlizus bruchii, Pyrearinus termitilluminans, Pyrophorus punctatissimus and P. divergens, representing three genera. In addition, in situ microspectrophotometric absorption spectra were obtained for visual and screening pigments in P. punctatissimus and P. divergens species. In all species, the electroretinographic S(λ) functions showed broad peaks in the green with a shoulder in the near-ultraviolet, suggesting the presence of short- and long-wavelength receptors in the compound eyes. The long-wavelength receptor in Pyrophorus species is mediated by a P540 rhodopsin in conjunction with a species-specific screening pigment. A correspondence was found between green to yellow bioluminescence emissions and its broad S(λ) maximum in each of the four species. It is hypothesized that in elaterids, bioluminescence of the abdominal lantern is an optical signal for intraspecifc sexual communication, while the signals from the prothoracic lanterns serve to warn predators and may also provide illumination in flight.     

Bioluminescent Mycena species from São Paulo, Brazil

Six species of bioluminescent agarics are described and illustrated from a single site in primary Atlantic Forest habitat in the Parque Estadual Turistico do Alto Ribeira, Sao Paulo State, Brazil. These include two new taxa of Mycena, viz. M. asterina and M. lucentipes. Luminescence in Mycena fera, M. singeri and M. discobasis is reported for the first time. In addition an undeterminable luminescent Mycena species is described and additional specimens of Gerronema viridilucens are documented. An accounting of known bioluminescent species of Mycena and a discussion of why they luminesce are presented.     

Atrial Fibrillation and Colonic Neoplasia in African Americans

Background

Colorectal cancer (CRC) and atrial fibrillation/flutter (AF) share several risk factors including increasing age and obesity. However, the association between CRC and AF has not been thoroughly examined, especially in African Americans. In this study we aimed to assess the prevalence of AF and its risk factors in colorectal neoplasia in an African American.

Methods

We reviewed records of 527 African American patients diagnosed with CRC and 1008 patients diagnosed with benign colonic lesions at Howard University Hospital from January 2000 to December 2012. A control group of 731 hospitalized patients without any cancer or colonic lesion were randomly selected from the same time and age range, excluding patients who had diagnosis of both CRC and/or adenoma. The presence or absence of AF was based upon ICD-9 code documentation. The prevalence of AF in these three groups was compared by multivariate logistic regression.

Results

The prevalence of AF was highest among CRC patients (10%) followed by adenoma patients (7.2%) then the control group (5.4%, P for trend = 0.002). In the three groups of participants, older age (P<0.008) and heart failure (P<0.001) were significantly associated with higher risk of AF. After adjusting for these risk factors, CRC (OR: 1.4(95%CI):0.9–2.2, P = 0.2) and adenoma (OR: 1.1(95%CI):0.7–1.6, P = 0.7) were not significantly associated AF compared to control group.

Conclusions

AF is highly prevalent among CRC patients; 1 in 10 patients had AF in our study. The predictors of AF in CRC was similar to that in adenoma and other patients after adjustment for potential confounders suggesting that the increased AF risk in CRC is explained by higher prevalence of AF risk factors.     

Assessment of the treatment of chronic hepatitis C in the state of Mato Grosso, central Brazil

In Brazil, the treatment of hepatitis C virus (HCV) infection is funded by the national public health system (SUS). To evaluate treatment results in the state of Mato Grosso, central Brazil, we have consulted the files of the office of the State Department of Health responsible for supplying such medications. We obtained information on 232 treatments of 201 patients who underwent treatment in or prior to 2008. The study was conducted by reviewing medical records, making telephone calls and interviewing the assistant physicians. Thirty-nine patients (19.4%) had cirrhosis and HCV genotype 1 predominated (64.3%). Excluding patients with comorbidities or treatment without ribavirin we analysed 175 treatments (sustained virologic response occurred in 32.6% of cases). Twenty-six of these 175 were retreatments and the sustained virological response (SVR) rate among them was 30.8%; the SVR rate was 32.9% among those receiving treatment for the first time. The SVR rate of genotype 1 patients was 27.8%, whereas it was 37.5% in non-1 genotype patients. The adjusted multivariate analysis showed association of SVR with the absence of cirrhosis [odds ratio (OR): 7.7; confidence interval (CI) 95%: 2.5, 33.3], the use of pegylated interferon (OR: 5.8; CI 95%: 1.5, 21.4), non-1 genotype (OR: 5.3; CI 95%: 1.7, 16.7) and uninterrupted treatment (OR: 9.0; CI 95%: 3.3, 45.4). The SVR rates were similar to those found in other Brazilian studies about HCV, but lower than those found in national and international clinical trials. These data suggest that the treatments of chronic hepatitis C that are made available by SUS does not, under normal conditions, work as well as the original controlled studies indicated.     

Neonothopanus gardneri: a new combination for a bioluminescent agaric from Brazil

The bioluminescent agaric, Agaricus gardneri Berk., was rediscovered recently in central Brazil. The new combination, Neonothopanus gardneri, is proposed for this long-forgotten taxon supported by morphological and molecular data.     

Fungi bioluminescence revisited

A review of the research conducted during the past 30 years on the distribution, taxonomy, phylogeny, ecology, physiology and bioluminescence mechanisms of luminescent fungi is presented. We recognize 64 species of bioluminescent fungi belonging to at least three distinct evolutionary lineages, termed Omphalotus, Armillaria and mycenoid. An accounting of their currently accepted names, distributions, citations reporting luminescence and whether their mycelium and/or basidiomes emit light are provided. We address the physiological and ecological aspects of fungal bioluminescence and provide data on the mechanisms responsible for bioluminescence in the fungi.     

Biofilm production by multiresistant Corynebacterium striatum associated with nosocomial outbreak

Corynebacterium striatum is a potentially pathogenic microorganism that causes nosocomial outbreaks. However, little is known about its virulence factors that may contribute to healthcare-associated infections (HAIs). We investigated the biofilm production on abiotic surfaces of multidrug-resistant (MDR) and multidrug-susceptible (MDS) strains of C. striatum of pulsed-field gel electrophoresis types I-MDR, II-MDR, III-MDS and IV-MDS isolated during a nosocomial outbreak in Rio de Janeiro, Brazil. The results showed that C. striatum was able to adhere to hydrophilic and hydrophobic abiotic surfaces. The C. striatum 1987/I-MDR strain, predominantly isolated from patients undergoing endotracheal intubation procedures, showed the greatest ability to adhere to all surfaces. C. striatum bound fibrinogen to its surface, which contributed to biofilm formation. Scanning electron microscopy showed the production of mature biofilms on polyurethane catheters by all pulsotypes. In conclusion, biofilm production may contribute to the establishment of HAIs caused by C. striatum.