Vesicle movements are governed by the size and dynamics of F-actin cytoskeletal structures in bovine chromaffin cells

Dense vesicles can be observed in live bovine chromaffin cells using fluorescent reflection confocal microscopy. These vesicles display a similar distribution, cytoplasmic density and average size as the chromaffin granules visualized by electron microscopy. In addition, the acidic vesicles labeled with Lysotracker Red comprised a subpopulation of the vesicles that are visualized by reflection fluorescence. A combination of fluorescence reflection and transmitted light images permitted the movements of vesicles in relation to the cortical cytoskeleton to be studied. The movement of vesicles located on the outside of this structure was restricted, with an apparent diffusion coefficient of 1.0+/-0.4 x 10(-4) microm(2)/s. In contrast, vesicles located in the interior moved much more freely and escaped from the visual confocal plane. Lysotracker labeling was more appropriate to study the movement of the faster moving vesicles, whose diffusion coefficient was five times higher. Using this type of labeling we confirmed the restriction on cortical movement and showed a clear relationship between vesicle mobility and the kinetics of cytoskeletal movement on both sides of the cortical cytoskeleton. This relationship was further emphasized by studying cytoskeletal organization and kinetics. Indeed, an estimate of the size of the cytoskeletal polygonal cages present in the cortical region and in the cell interior agreed well with the calculation of the theoretical radius of the cages imprisoning vesicle movement. Therefore, these data suggest that the structure and kinetics of the cytoskeleton governs vesicle movements in different regions of chromaffin cells.     

The heterologous overexpression of <Emphasis Type="Italic">hsp23</Emphasis>, a small heat-shock protein gene from <Emphasis Type="Italic">Trichoderma virens</Emphasis>, confers thermotolerance to <Emphasis Type="Italic">T. harzianum</Emphasis>

An EST showing high values of identity with genes coding for small heat shock proteins (sHSPs) was selected from an EST library collection of Trichoderma virens T59. The cDNA gene (hsp23) with a sequence size of 645 bp long was amplified by PCR. The expression of this gene was evaluated in cultures grown at temperatures ranging from 4 to 41°C. An increased level of expression was detected when the fungus was grown at extreme temperatures (4, 10 or 41°C). A high-expression level was also observed when the fungus was grown in 10% ethanol for 4 h. The hsp23 gene was present as a unique copy in the T. virens genome, and a homologous gene was also present in other five investigated Trichoderma species. Strain T. harzianum T34 was transformed with the hsp23 gene from T. virens T59 under the control of the pki (pyruvate kinase) promoter from T. reesei and the ble (phleomycin resistance) gene as selection marker. Statistically significant differences were detected between the strains T34 and two selected transformants in the biomass quantities obtained after heat shock treatment and in the colony diameters after incubation at 4°C for 2 months.     

Activity in vitro of twelve antibiotics against clinical isolates of extended-spectrum beta-lactamase producing Escherichia coli

Twelve beta-lactam and non-beta-lactam antibiotics were evaluated against 115 clinical isolates of extended-spectrum beta-lactamase-producing (ESBLs) Escherichia coli using a broth microdilution test in accordance with the CLSI guidelines. Susceptibility was 100% with imipenem, ertapenem and amikacin, 95.7% with piperacillin-tazobactam, 91.3% with cefoxitin, 87% with tobramycin, 81.7% with amoxicillin-clavulanate, 80% with cefepime, 67.8% with ceftazidime, 27.8% with ciprofloxacin, 27% with levofloxacin and 13% with ceftriaxone. Ertapenem was the antibiotic with the lowest minimum inhibitory concentrations (MICs) for all isolates. There were no clinically relevant differences in the activity of the antibiotics in the presence of CTX-M-9 or SHV enzymes.     

The role of dipolar interaction in the quantitative determination of particulate magnetic carriers in biological tissues

The use of magnetic ac susceptibility measurements of biological tissues in the quantitative determination of their particulate magnetic carrier content has been investigated. In a first step, an ad hoc series of agar dilutions of the superparamagnetic contrast agent Endorem, used as an example of magnetic carrier, has been characterized to determine the influence of the dipolar interaction. With this result in hand, the quantitative determination of the content of a magnetic carrier in the ex vivo liver and spleen tissues of rats, to which the same compound was previously administered, has been accomplished. It is shown that, by careful interpretation of the temperature dependent out-of-phase susceptibility profiles in the cryogenic range, it is possible to discern between the magnetic contribution of the carrier and that of biomineral iron, being able to detect magnetic carrier iron concentrations of the order of 1 microg Fe g(-1) dry tissue. At the usual dosages in humans, necessarily small to avoid toxicity, the amount of magnetic carrier in terms of elemental iron is small compared to physiological iron. The choice of their most salient property, that is, the magnetic moment, therefore makes the quantification possible even in such a minority proportion. By analysing the magnetic dynamics, through a method that just considers the in-phase and the out-of phase components of the susceptibility at only one frequency, it has been possible to decouple the carrier concentration from eventual local aggregations, opening the possibility of investigating the degree of particle clustering at a larger observation scale compared with transmission electron microscopy, and independently of physiological iron.     

Positional vertigo afterwards maxillary dental implant surgery with bone regeneration

Benign paroxysmal positional vertigo (BPPV) is the most common form of vertigo. It is caused by loose otoconia from the utricle which, in certain positions, displaced the cupula of the posterior semicircular canal. BPPV most often is a result of aging. It also can occur after a blow to the head. Less common causes include a prolonged positioning on the back (supine) during some surgical procedures. Additionally one can include in this ethiopathogenesis the positioning required during the maxillary dental implant surgery with bone regeneration related to a forced head positioning and inner ear trauma induced by dental turbine noise working in the maxillary bone. Two cases of patients who suffered BPPV after undergoing maxillary dental implant with bone regeneration procedures are reported. Diagnosis and treatment are also described.     

Progressive facial hemiatrophy with associated osseous lesions

Progressive facial hemiatrophy (PFH) is a rare condition characterized by the slow, progressive appearance of a unilateral facial atrophy that affects the skin, subcutaneous tissue, muscle and bone. We report the case of a 60-year-old female patient whose cutaneous symptoms commenced in 1987 in the form of a purplish erythema on the left side of her face and neck, which subsequently remitted giving rise to an indurated region in the left maxillary region. Since 1995 until the present day, she has developed facial hemiatrophy on the left side accompanied by progressive osseous reabsorption of the upper maxilla and left mandible with atrophy of soft tissue. The association of the onset of PFH with progressive osteolysis of the maxilla has not been previously reported in an adult patient.     

The application of microscopic surgery in dentistry

The use of the microscope as a tool for practising Medicine, especially in surgical specialisations, has been established for decades. The microscope was first used in OdontologyDentistry back to the 1970s and 1980s, and was introduced more widely (although it was still far from being in general use) during 1990s. The purpose of this article is to describe the main applications of the microscope in OdontologyDentistry today, as well as providing odontologists and stomatologists, whether specialists or in general practice, with information about microscopic OdontologyDentistry for better patient care. This work also gives particular importance to matters needed to achieve the necessary manual dexterity to work in a magnified operating field using a surgical microscope (SM).