Fate of coagulant species and conformational effects during the aggregation of a model of a humic substance with Al13 polycations.

A model of a humic substance (MHS) obtained from auto-oxidation of catechol and glycine, was aggregated at pH 6 and 8 with Al(13) polycations. The fate of Al(13) coagulant species upon association with MHS functional groups was studied using solid state (27)Al Magic-angle spinning (MAS) NMR and CP-MAS (13)C NMR. Electrophoretic measurements and steady-state fluorescence spectroscopy with pyrene as a fluoroprobe, were combined to investigate structural re-organization of humic material with aluminum concentration. MAS (27)Al NMR revealed that the coagulant species are Al(13) polycations or oligomers of Al(13) units at both pHs. CP MAS (13)C spectra indicated that, at low Al concentration, hydrolyzed aluminum species bind selectively to carboxylic groups at pH 6 and to phenolic moieties at pH 8. At higher coagulant concentrations, the remaining functional groups also interact with hydrolyzed Al to yield similar CP MAS (13)C spectra in the optimum concentration range. Negative values of electrophoretic mobility were obtained at optimum coagulant concentrations even though an overall charge balance was achieved between MHS anionic charge and Al(13) cationic charge at pH 6. The polarity-sensitive fluorescence of pyrene revealed that the interaction of Al(13) coagulant species with MHS functional groups induces the formation of intramolecular hydrophobic microenvironments. Such structural changes were reversed upon further addition of Al(13) polycations.

[Tansitional vesical cell carcinoma metastatizing to the sphenoid sinus]. / Metástasis esfenoidal de un carcinoma de células trancisionales de la vejiga.

Secundary tumors of the paranasal sinus are very uncommon with only one hundred cases reported in the literature up to 2001. The commonest site of the primary tumor is the kidney. The maxillary sinus is most often involved. The Sphenoid sinus is the rarest site. We report a rare case of metastasis to the sphenoid sinces from a transitional cell bladder tumor in a 69-year-old man who died after treatment with chemotherapy and we also review the liteature.

PAH dissipation in a contaminated river sediment under oxic and anoxic conditions.

A batch experiment was conducted to compare PAH degradation in a polluted river sediment under aerobic and anaerobic conditions, and to investigate whether input of fresh organic material (cellulose) could enhance such degradation. All measurements were checked against abiotic control treatments to exclude artifacts of sample preparation and non-biological processes like aging. Three- and four-ring PAHs could be degraded by the indigenous microbial community under aerobic conditions, but anaerobic metabolism based on iron and sulphate reduction was not coupled with PAH degradation of even the simplest 3-ring compounds like phenanthrene. Cellulose addition stimulated both aerobic and anaerobic respiration, but had no effect on PAH dissipation. We conclude that natural attenuation of PAHs in polluted river sediments under anaerobic conditions is exceedingly slow. Dredging and biodegradation on land under aerobic conditions would be required to safely remediate and restore polluted sites.

Effects of soil type upon metolachlor losses in subsurface drainage.

A field experiment at La Bouzule (Lorraine, France) investigated metolachlor movement to subsurface drains in two soil types, a silt loam and a heavy clay soil, under identical agricultural management practices and climatic conditions. Drainage volumes and concentrations of metolachlor in the soil plough layer and drainwater were monitored after herbicide application from May 1996 to February 1997, and from May to August 1998. Total losses in drainwater were 0.08% and 0.18% of the amount applied to the silt loam compared with 0.59% and 0.41% for the clay soil, in 1996/97 and 1998, respectively. In 1996/97, 32% of total metolachlor loss from the silt loam and 91% from the clay soil occurred during the spring/summer period following treatment. Peak concentrations were 18.5 and 171.6 microg l(-1) for the silt loam and 130.6 and 395.3 microg l(-1) for the clay soil during the spring/summer periods of 1996/97 and 1998, respectively. During the autumn/winter period, concentrations did not exceed 2.2 microg l(-1) for the silt loam and 2.6 microg l(-1) for the clay soil. The experimental results indicate that metolachlor losses in drainwater were primarily caused by preferential flow (macropore flow) which was greater in the clay soil than in the silt loam, and occurring mainly during the spring/summer periods.

Major review: ocular sighting dominance: a review and a study of athletic proficiency and eye-hand dominance in a collegiate baseball team.

REVIEW: Laterality preference in sensory and motor functions of symmetrically disposed organisms have been studied for centuries. The relation between handedness and the eyes and vision (ocular sighting dominance) has been a focal point despite their physiologic dissimilarity. STUDY: To examine a college varsity baseball team for handedness and ocular sighting dominance to determine if their patterns of eye-hand dominance differed from the normal population and/or contributed to their individual relative success compared to their peers. Specifically: whether crossed eye- hand dominance favors the batter and uncrossed eye-hand dominance favors the pitcher. SUBJECTS AND METHODS: Twenty five UF varsity players were examined. All were male. Their visual acuity, stereoscopic vision, ocular motility and ocular sighting dominance were determined, the last by a pointing test which allowed the diagnosis of a central form of ocular dominance, but was not per se affected by handedness. Handedness was determined by preferred arm for throwing or hitting. No subject was ambidextrous. A control population was established consisting of the first 100 consecutive adults seen by the first author in the UF Eye Center with 20/20 vision O.U. and a normal eye exam. RESULTS: The control group displayed eye-hand dominance patterns similar to those previously reported in the literature for the general population. In the experimental group of baseball players, the incidence of conventionally predominant (in normals) ipsilateral or uncrossed eye-hand dominance was much lower (39%) than the normal control population (65%). The incidence of contralateral or crossed eye- hand dominance was 35%, twice that of the normal control population (18%) (p<0.01). The incidence of central ocular dominance with right or left handedness was 26% or 50% higher than a normal control population (17%) (p<0.25). With regard to individual performance, those players with central ocular dominance, whether right or left handed, were the most successful players in both pitching and batting. Pitchers who were uncrossed eye-hand dominant were distinctly more successful than crossed. Batters who were crossed eye-hand dominant were slightly more successful than uncrossed. CONCLUSIONS: The pattern of eye-hand dominance appears related to athletic proficiency for baseball. Warning: Note well: This information may be useful in career guidance but does not justify or medically indicate attempts to alter ocular sighting dominance or eye-hand dominance patterns as these are determined probably genetically or at such an early age that they cannot be successfully altered later. Attempts to so alter them are historically fraught with irremediable psychological or physical injury to the subject, including permanent incapacitating double vision.

[Intra-laryngeal ectopic thyroid tissue. Report of one case and review of the literature]. / Tejido tiroideo ectópico intralaríngeo. Presentación de un caso clínico y revisión de la literatura.

A Ectopic thyroid is any thyroid tissue not located in his normal anatomic situation. There have been described four general groups within the upper aerodigestive tract: lingual, sublingual, thyroglossal and intralaryngotracheal. Intralaryngotracheal thyroid tissue is rare and constitute 7 per cent of all intratracheal tumours, and it represents a problem of diagnosis and management. The controversy about the genesis of this tumours remains. There are two established theories: "the malformation theory" and "the ingrowth theory". These tumours affect more frequently adult female. Intralaryngotracheal thyroid have been mainly reported on the posterior-left wall of the trachea. The most common clinical feature is stridor due to progressive upper airway obstruction. Up to 75% of the intralaryngotracheal goiters are associated with and external goiter. This paper reports a case of ectopic subglotic thyroid in a 42 year-old-female. The embryology, diagnosis and management of this tumours are discussed.

[Frontal ethmoid metastases of prostatic carcinoma. Report of one case and review of the literature]. / Metástasis fronto-etmoidal de adenocarcinoma prostático. Presentación de un caso clínico y revisión de la literatura.

Prostatic metastases in the nose and paranasal sinuses are rare. Less than 100 cases have been reported in the literature. Kidney are the commonest site of primary tumour, followed by lung and breast. Only 10 cases have previously been reported in the world literature. Prostatic metastases have been mainly reported in the sphenoid sinus. This paper reports one case of metastases of prostatic carcinoma in the fronto-ethmoid sinus in a 72 years old male. The clinical picture includes acute fronto-ethmoid right sinusitis, severe exophthalmos and chemosis. The CT scan showed extensive soft tissue filling the maxillary, ethmoid cells, sphenoid and frontal right sinuses, with subdural abscess. Biopsies from the fronto-ethmoid mass showed infiltration by adenocarcinoma with positive immunostaining for prostatic specific antigen. We also review the literature about metastases involving the nose and paranasal sinuses.

[Small-cell carcinoma of the larynx]. / Carcinoma de células pequeñas de laringe.

Primary small-cell (also known as oat-cell) neuroendocrine carcinoma of the larynx is an infrequent tumor. We report a case of epiglottic oat-cell carcinoma in a 57-year-old man. Its association with other malignant neoplasms and aggressive behavior in spite of treatment are discussed.

[Quality of life in patients treated for head and neck cancer]. / Calidad de vida en pacientes tratados por un cáncer de cabeza y cuello.

In this paper we have studied the quality of life of patients that underwent treatment for an early laryngeal carcinoma in comparison to others with an advanced head and neck cancer. We have studied 62 patients (T1N0M0, T2N0M0) with laryngeal carcinoma diagnosed between 1990 and 1998. We have applied the European EORTC QOL C-30 questionnaire, and more specifically its head and neck module (H&N 35). The results were compared with a heterogeneous group of 48 patients with different degrees of head and neck cancers. The quality of life of our patients who were treated for an early glottic cancer was better in many functional scales of the EORTC and in many specific symptom scales of the H&N 35, but not in global cancer symptoms.

Distribution and location of polycyclic aromatic hydrocarbons (PAHs) and PAH-degrading bacteria within polluted soil aggregates.

A study was conducted to determine the location and distribution of PAH and PAH-degrading bacteria in different aggregate size fractions of an industrially polluted soil. The estimation of PAH-degrading bacteria using an MPN microplate technique indicated that these bacteria are most numerous in the aggregate size fractions corresponding to fine silt (2-20 microm) and clay (<2 microm) compared to larger fractions or unfractionated soil. PAH concentrations were also highest in the aggregate size fraction corresponding to fine silt. Similar results were found in a spiked soil (incubated for 6 months) with similar carbonated minerals. Transmission electron microscopy observations showed that the autochtonous PAH-degrading bacteria were embedded in the aggregates where PAHs were abundant. In spite of this extensive co-localisation PAH degradation was limited during 6 months incubation. This indicates that factors other than spatial distribution and PAH degrading ability control degradation rates. The fine silt fraction of the industrial soil had an elevated C/N ratio (35) compared to the clay fraction (C/N: 16). Thus the fraction which assumably had the highest specific surface area contained less PAH but similar numbers of PAH-degraders. N thus seem to play an important role in the long term, but as PAH degradation was low in fine size fractions, other sources/factors were probably limiting (easily degradable C, P org, O2 etc.). Based on these findings, soil particle organization and structure of soil aggregates appear to be important for the characterization of a polluted soil (localization and sequestration). Manipulations that modify aggregation in polluted soils could thus potentially influence the accessibility and biodegradability of PAHs.

Availability and persistence of isoproturon under field and laboratory conditions.

Field and laboratory tests were conducted to investigate the disappearance and decrease in availability of the herbicide isoproturon in soil with time. Monitoring the fate of 14C-labeled isoproturon gave the persistence of the herbicide under different conditions. The calculated half-life (DT50) of the extractable parent product was close to 19 days for the two experiments, whereas half-lives of exhaustive extractable 14C-residues averaged 22 days under controlled conditions versus 48 days in the field. Moreover, if nonextractable 14C-residues were taken into account in estimating isoproturon fate, the DT50 of radioactive residues in soil (extractable parent and degradation products + nonextractable residues) reached 1 to 1.4 years under field and controlled conditions, respectively. The variability of disappearance rates for the different kinds of residues is discussed within a wider definition of persistence.

Rhizosphere effects on microbial community structure and dissipation and toxicity of polycyclic aromatic hydrocarbons (PAHs) in spiked soil.

Phytoremediation of soils polluted with polycyclic aromatic hydrocarbons (PAHs) has so far neglected the possible role of the ubiquitous symbiotic associations between plant roots and fungi known as arbuscular mycorrhizas. A time course laboratory experiment with clover and ryegrass grown on spiked [500 + 500 + 50 mg kg-1 of anthracene, chrysene and dibenz(a,h)anthracene] soil demonstrated for the first time that dissipation of condensed PAHs may be enhanced in the presence of arbuscular mycorrhiza [66 and 42% reductions in chrysene and dibenz(a,h)anthracene, respectively, versus 56 and 20% reductions in nonmycorrhizal controls]. Addition of a surfactant accelerated initial PAH dissipation but did not attain final PAH concentrations below those obtained with nonmycorrhizal plants. Toxicity tests (earthworm survival and bioluminescence inhibition in Vibrio fischeri) indicated that mycorrhiza reduced the toxicity of PAHs and/or their metabolites and counteracted a temporally enhanced toxicity mediated by surfactant addition. Phospholipid fatty acid profiles demonstrated that the imposed treatments altered the microbial community structure and indicated that the mycorrhiza-associated microflora was responsible for the observed reductions in PAH concentrations in the presence of mycorrhiza.