Salmonella enterica serovars in absence of ttrA and pduA genes enhance the cell immune response during chick infections

Salmonella spp. is one of the major foodborne pathogens responsible for causing economic losses to the poultry industry and bringing consequences for public health as well. Both the pathogen survival ability in the intestinal environment during inflammation as well as their relationship with the host immune system, play a key role during infections in poultry. The objective of this study was to quantify the presence of the macrophages and CD4⁺/CD8⁺ cells populations using the immunohistochemistry technique, in commercial lineages of chickens experimentally infected by wild-type and mutant strains of Salmonella Enteritidis and Salmonella Typhimurium lacking ttrA and pduA genes. Salmonella Enteritidis ∆ttrA∆pduA triggered a higher percentage of the stained area than the wild-type, with exception of light laying hens. Salmonella Typhimurium wild-type strain and Salmonella Typhimurium ∆ttrA∆pduA infections lead to a similar pattern in which, at 1 and 14 dpi, the caecal tonsils and ileum of birds showed a more expressive stained area compared to 3 and 7 dpi. In all lineages studied, prominent infiltration of macrophages in comparison with CD4⁺ and CD8⁺ cells was observed. Overall, animals infected by the mutant strain displayed a positively stained area higher than the wild-type. Deletions in both ttrA and pduA genes resulted in a more intense infiltration of macrophages and CD4⁺ and CD8⁺ cells in the host birds, suggesting no pathogen attenuation, even in different strains of Salmonella.

Dynamics of the dissolved organic matter in a stream-lake system within an extremely acid to neutral pH range: Agrio-Caviahue watershed

The Agrio-Caviahue is a natural stream-lake system composed of the Upper Agrio River (UAR) -Lake Caviahue-Lower Agrio River (LAR). The system has a broad pH gradient from extremely acid in the hot spring to almost neutral pH only 60 km downstream the source, and varies as a function of the distance. The aim of this study was to analyze the dynamics of the dissolved organic matter (DOM) of this extreme system. For that matter, an absorbance and fluorescence-based characterization was performed on natural water samples and hydrophobic resin DOM extracts during different seasons in nine sampling stations. Between August and December, the hydrological connectivity is maximum due to precipitation and snowmelt, respectively. During these months, the stream that exits the lake governs the chemical characteristics downstream mainly in the period of high connectivity. In contrast, in the dry season when the flow of LAR is minimum, the two major affluents of this river influence its pH and DOM features, and deliver inputs of humified DOM from the wetlands where the tributaries are born. DOM was characterized by having low absorbance. The PARAFAC analysis of the fluorescent DOM (FDOM) validated three fluorescent components in the natural samples (with humic and non-humic features), two of which were also recorded in the extracts, meaning that no additional hydrophobic components were missed under the limit of detection of the fluorometer. The unique features of Agrio-Caviahue DOM resemble those found in DOM from Yellowstone hot springs, both acid and alkaline.

Analysis of photorefractive optical damage in lithium niobate: application to planar waveguides

Photorefractive optical damage of single beams in LiNbO(3) crystals is analyzed within a framework of two photoactive centres (Fe(2+)/Fe(3+) and Nb(Li) (4+)/Nb(Li) (5+)). It compares model simulations and significant experimental measurements in LiNbO(3) waveguides. A good agreement is found in the performed comparisons: photovoltaic currents, refractive index changes and, especially relevant, in degraded beam-profiles. The progress of the degraded wavefront has been simulated by implementing a finite-difference beam-propagating method which includes the model equations. These results, together with previous ones on grating recording, provide a comprehensive, satisfactory explanation of most important questions on photorefractive optical damage.

Understanding light intensity thresholds for catastrophic optical damage in LiNbO3

The appearance of light intensity thresholds for catastrophic optical damage in LiNbO3 is satisfactorily explained by using a photorefractive model based on the Fe(2+)?Fe(3+) and NbLi(4+)?NbLi(5+) defect pairs. Model simulations of the photorefractive amplification gain as a function of the light intensity present sharp threshold behavior. A similar behavior is shown by the saturating refractive index change. In agreement with experiments, predicted thresholds appear shifted towards higher intensities (up to a 10(4) factor) when the Nb(Li) concentration is decreased or the temperature is increased. The model also explains very recent data on the threshold enhancement with the Fe(2+)/Fe(3+) ratio in optical waveguides.

Optical damage control via the Fe2+/Fe3+ ratio in proton-exchanged LiNbO3 waveguides

Intensity thresholds for the onset of optical damage in alpha-phase proton-exchanged waveguides on undoped LiNbO(3) have been increased from the substrate value to a factor 500 greater. This has been achieved by increasing the exchange time, which in turn increases the [Fe(2+)]/[Fe(3+)] ratio in the guide. Intensity thresholds have been measured with a single-beam configuration, while [Fe(2+)]/[Fe(3+)] ratios have been determined from decay measurements during optical erasure of photorefractive gratings. In heavily Fe-doped guides, thresholds are too small to be measured, but the dependence of the Fe(2+) absorption on the exchange time appears similar to undoped samples.

Silicone granulomatous lymphadenopathy and siliconomas of the breast

In the present study, two histologically-distinct cases of granulomatous lymphadenitis induced by dimethylpolysiloxane (silicone polymer) implants were studied. Four and six years after implant, and following surgery for breast cancer, painful homolateral axillary adenopathies were observed and biopsied. In both cases, histological examination led to a diagnosis of "silicone-induced granulomatous adenitis" requiring removal of implants. Foreign-body granulomas (siliconomas) were observed in surrounding tissue with no apparent rupture of implant capsules; however, visible retraction, hardening and scattered calcifications were noted. The presence of silica was revealed by incineration of a number of biopsied lymph nodes, a technique not hitherto used in the study of this pathology. A review is offered of the literature available.

Nonosseous athletic injuries of the elbow, forearm, and hand

This article deals with soft-tissue injuries of the upper extremity incurred by competitive athletes. The authors describe the pathophysiology, conservative and operative management of musculotendinous elbow injuries, entrapment neuropathy, tendinous disorders, vascular injuries, and dermatologic conditions in athletes. Protective gear for many of the aforementioned injuries are also described.

Tuberculous optochiasmatic arachnoiditis

Eighl cases of optochiasmatic arachnoiditis secondary to tuberculous leptomeningitis were treated with microsurgical intervention at the Department of Neurosurgery of La Raza Medical Center of the Mexican Social Welfare Institute. All of the patients had been amaurotic before the operation and displayed complete recovery of their vision during the immediate postoperative period. Microsurgical and pharmacological (antituberculous chemotherapy and steroids) treatment can cure such patients.