Role of ferrihydrite in adsorption of three imidazolinone herbicides

Adsorption of the imidazolinone herbicides imazapyr, imazethapyr, and imazaquin on synthetic ferrihydrites, either freeze-dried or not-freeze-dried, has been studied. The synthetic ferrihydrites were characterized by X-ray diffraction, scanning electron micrographs, and specific area determination. On each ferrihydrite, adsorption was found to be strongly dependent on pH. The highest extent of adsorption took place at pH values close to the pK(a) of the carboxylic group of the herbicides. No adsorption was observed at pH > 8. The freeze-drying process reduced the adsorptive capacity of the ferrihydrite by formation of larger aggregates provoking a decrease of the surface area. The chemical differences between the herbicides did not strongly affect the adsorption process of the herbicides. However, imazaquin was more adsorbed than the other two herbicides, in particular at pH close to its pK(a).

Adsorption of imidazolinone herbicides on ferrihydrite-humic acid associations

Adsorption of the imidazolinone herbicides imazapyr, imazethapyr and imazaquin was studied on two binary systems (ferrihydrite-humic acid) prepared by treating ferrihydrite (Fh) immediately after its precipitation with a soil humic acid (HA) at different loadings (4% and 8% HA content), and on a blank ferrihydrite sample prepared in the same way, but without HA addition. Imidazolinone adsorption on pure Fh and on the 4% Fh-HA decreased with increasing of the herbicide hydrophobicity (imazaquin<imazethapyr<imazapyr), whereas on the 8% Fh-HA system the order of adsorption was nearly the same, indicating that higher amounts of HA on Fh increase the hydrophobicity of the surface and thus increases its affinity for the herbicides, specially for imazaquin. Adsorption was also enhanced by low pH values and slight changes in pH enhanced the contribution of each component in adsorption. Both the nature of the surface exposed and its ability to interact with herbicides are greatly altered by the mutual interaction of Fh and HA. The results show that albeit artificial polyphasic associations are more representative of the real situation than single model components and are thus better indicators of the behaviour of a given herbicide in the soil.

Behavior of cinosulfuron in paddy surface waters, sediments, and ground water

Cinosulfuron (3-(4,6-dimethoxy-1,3,5-triazin-2-yl)-1-[2-(2-methoxyethoxy)-phenylsulfonyl]-urea) is a sulfonylurea herbicide used to control a wide range of broadleaf weeds in rice (Oryza sativa L.). A 2-yr field study was conducted in northwest Italy to determine the effect of cinosulfuron on surface and subsoil waters in rice paddies. Cinosulfuron was applied at 70 g a.i. ha(-1) on 35 ha of flooded rice. After the treatment, the change in herbicide concentration over time was studied by analyzing water and sediment samples in a test paddy field (2.16 ha, located in the treated area), water in a spring and a pond (both located near the test paddy), two wells (up- and downhill to the treated area), and two piezometers (along the test paddy levee). To better understand some of the field study results, cinosulfuron degradation was also evaluated in the laboratory in solutions buffered to different pH values. Two weeks after the treatment, the cinosulfuron concentration in the paddy water decreased by about 60%. No cinosulfuron was detected at about 2.5 mo after the treatment. The concentration in the sediment gradually increased after the treatment, reaching the highest value (13.53 microg kg(-1)) 3 wk later. The maximum cinosulfuron content in the spring and pond were 0.91 and 0.29 microg L(-1), respectively, and these were detected 60 to 90 days after treatment (DAT). The water collected in the piezometers reached the highest concentration (0.99 microg L(-1)) 29 DAT. Cinosulfuron was never detected in the wells. In the degradation study at different pH values, cinosulfuron degraded rapidly at low pH values.

Liquid chromatographic determination of triasulfuron in soil

Two extraction methods were developed for the determination of triasulfuron in soil. Method I included extraction with methanol-phosphate buffer at pH 7 (2 + 1, v/v), liquid-liquid partition with dichloromethane, and cleanup on a liquid chromatographic Si adsorption solid-phase extraction tube. In Method II, Extrelut was added and the sample was then extracted with acetonitrile. In both cases, the extracts were analyzed by liquid chromatography (LC) with UV detection and the LC peak was confirmed by LC/mass spectrometry (MS). The 2 methods were tested on 3 soils having different physicochemical characteristics. Method I gave 83% average recovery and a determination limit of 0.4 microg/kg soil. Method II gave 67% average recovery and a determination limit of 2 microg/kg soil. Examples of application of Method I to field samples are reported.

Insulin-like growth factor-I (IGF-I) and IGF-binding protein-3 (IGFBP-3) concentrations compared to stimulated growth hormone (GH) in the evaluation of children treated for malignancy

OBJECTIVE

The aim of this investigation was to evaluate the utility of IGF-I and IGFBP-3 determinations in screening for GH deficiency (GHD) in children previously submitted to treatment for childhood malignancy.

PATIENTS AND METHODS

We compared the GH responses to two pharmacological tests (arginine and levo-dopa) with the IGF-I and IGFBP-3 levels in 48 patients (29 boys) who had undergone bone marrow transplantation (BMT) (36 patients) or treatment for a solid cranial tumor (12 patients).

RESULTS

22 patients (45.8%) showed GHD (i.e. GH peak < 8 ng/ml in both tests), and only three (13.6%) of the GHD patients had concomitant low IGF-I levels (i.e. -2 SD below the normal mean) and only one (4.5%) an abnormal IGFBP-3 value (i.e. -2 SD below the normal mean). Among the 26 children with normal GH secretion, 21 (80.8%) also showed normal IGF-I and IGFBP-3 levels, three (11.5%) had a concomitant low IGF-I value and two (7.7%) a concomitant low IGFBP-3 value. A significant correlation was found between GH secretion and age at diagnosis (r = 0.26, P < 0.05), and between IGF-I and IGFBP-3 (r = 0.52, P < 0.0001), but not between GH and IGF-I or IGFBP-3. Comparing the growth pattern of these patients from diagnosis to the first year after therapy or BMT, we found that while individual height changes did not correlate with the GH peak, a significant correlation was found between height SDS decrease and IGF-I (r = 0.31, P < 0.05) or IGFBP-3 SDS (r = 0.37, P < 0.01).

CONCLUSION

Our results indicate that the cut-off of -2 SD for IGF-I and IGFBP-3 was insensitive in screening for GHD. A normal value did not exclude a subnormal GH response to provocative tests and therefore although IGF-I and IGFBP-3 levels may be indicators of the growth pattern, they cannot be used alone as a tool for identifying GHD children after treatment for childhood malignancy.

An interlaboratory study to find an alternative to the MPN technique for enumerating Escherichia coli in shellfish

Nine laboratories in eight countries tested 16 batches of common mussels (Mytilus edulis) over a 32 week period in order to find an alternative to the Most Probable Number (MPN) technique to enumerate E. coli. The alternatives investigated included the 3M Petrifilm system, the Merck Chromocult agar method and a Malthus conductance technique. The Petrifilm was found to be unsuitable and was subsequently dropped from the trial. After 669 analyses, a correlation of 0.83 was observed for log E. coli counts between the MPN and Chromocult methods and there was no significant evidence that either method tended to give higher readings than the other. The MPN was slightly better than the Chromocult method for repeatability but the Chromocult was slightly better for reproducibility. However, the observed differences are probably too small to be of practical importance. On the basis of these data therefore, the two methods appear equally suitable for E. coli enumeration in shellfish. There were poor correlations between these methods and the Malthus technique. A small but significant number of samples tested positive on the Malthus instrument but were recorded negative on the MPN and Chromocult tests. Subsequent analysis positively identified E. coli from these Malthus assays. After statistical analysis, errors were noted in both the MPN and Chromocult methods but it was found that there would be no statistical differences if the Chromocult agar were used as an alternative to the MPN technique.

Cartilage associated protein (CASP) is a novel developmentally regulated chick embryo protein

A subtracted cDNA library was generated to identify cDNAs specific for chondrocyte mRNAs preferentially expressed at the hypertrophic stage with respect to early differentiation stages. The characterization of a cDNA isolated from this library that hybridizes with a 1.8 kb mRNA is described here. This mRNA is expressed at extremely low levels in dedifferentiated chondrocytes cultured in adherent conditions, at very low levels in differentiating chondrocytes and at very high levels in hypertrophic chondrocytes cultured in suspension conditions. In the developing chick embryo this mRNA is detectable in RNAs extracted from several other tissues besides cartilage. The described cDNA contains a complete open reading frame coding for a polypeptide of about 33 kDa. Homology searches with known cDNA and protein sequences have revealed that the chicken protein is related to the amino-terminal half of two mammalian nuclear antigens. By immunohistochemistry with specific rabbit antisera a strong signal was detected in the cartilage extracellular matrix of selected regions of the developing skeleton. Because of this localization of the antigen we named this protein cartilage associated protein (hereafter referred to as CASP).

Expression of runtB is modulated during chondrocyte differentiation

The runt locus in Drosophila encodes a nuclear protein involved in embryo segmentation, sex determination/X dosage compensation, and neurogenesis. runt homologues have been identified in higher vertebrates. The encoded proteins share a domain of 128 amino acids called the runt domain. It has been reported that this domain mediates DNA binding and heterodimerization. Here, we analyze runtB expression during chondrocyte differentiation "in vitro" and "in vivo." We have first isolated, from a chondrocyte library, a cDNA clone coding for a runtB chicken homologue and containing a complete open reading frame. The predicted protein product is 84% identical to the mouse PEBP2alphaB2 isoform. By RT-PCR analysis we have also cloned the chicken cDNA fragment coding for delta alphaB2, the exon sequence included in the B1 isoform mRNA. On Northern blot analysis of cultured chondrocytes, runtB mRNA levels increase dramatically with the transition from stage 0 (dedifferentiated) to stages I and II (hypertrophic chondrocytes). Moreover, runt polypeptides were demonstrated in chondrocytes both in vivo and in vitro. These results suggest that runt plays a role in chondrogenic differentiation.

Cometabolic degradation of acifluorfen by a mixed microbial culture

Laboratory experiments were conducted to study the degradation of acifluorfen 5-[2-chloro-4-(trifluoromethyl)-phenoxyl]-2-nitrobenzoic acid by a mixed microbial population. Concentrations of acifluorfen up to 100 mg/l had no inhibitory effect on the growth of microbial culture. The microorganisms degraded acifluorfen through a cometabolic process in presence of 2-nitrobenzoate. The degradation rate of acifluorfen, determined by liquid chromatography analysis in batch cultures incubated under oxygen-limited conditions were compared. The degradation was slower under oxygen than oxygen-limited conditions. Aminoacifluorfen was produced in both conditions.

Trauma care in Italy: evidence of in-hospital preventable deaths

The quality of a trauma system can be assessed by the rate of preventable deaths. A random selected sample of 110 trauma patients was examined using both clinical and autopsy data. The assessors were asked the following question: If this patient had sustained the accident in front of the hospital in a normal working day, might death have been prevented? Death was found to be unavoidable in 61 cases, in 25 cases death was classified potentially preventable; 11 cases were classified as clearly preventable death. The main failures of treatment were identified as errors and delays during the first phases of in-hospital assessment and care. An improvement in the pre-hospital phase will be almost useless if the quality of the definitive in-hospital management is not addressed.

Comparative characterization of Acinetobacter strains isolated from different foods and clinical sources

Eighty-three Acinetobacter strains from clinical sources, and 170 from various foods (including fresh and spoiled meat and fish, vegetables, raw milk and cheese) were identified according to recently improved taxonomy, using a computer-assisted probabilistic method based on phenotyping tests. Apart from some atypical characters, most of the strains (94%) were identified to belong to the genospecies or groups of genospecies described in the literature. Among our strains from hospitals, the A. calcoaceticus- A. baumannii complex predominated, whereas the strains isolated from food were predominated by genospecies 7 (A. johnsonii), followed by genospecies 8/9 (A. lwoffii). The isolates from clinical environments showed a major incidence of antibiotic resistance, haemolytic strains and strains producing polysaccharidic material.

Modulation of tensin and vimentin expression in chick embryo developing cartilage and cultured differentiating chondrocytes

It has been proposed that tensin, in association with several other proteins, mediates the micro-filament-integrin link. Here we describe the isolation of clones spanning about 5 kb from the 3' end of tensin mRNA from cultured chick embryo chondrocyte and embryonic heart cDNA libraries. Tensin expression was investigated in cultured chick embryo cells. It was observed that tensin expression is dependent upon substrate adhesion and it is turned off after 7 days of suspension culture. This process is reversible. Tensin expression is also regulated during cartilage cell differentiation in vivo; at Hamburger and Hamilton stage 39-40, non-hypertrophic tibial chondrocytes express both RNA and protein while hypertrophic chondrocytes do not. In the culture system the expression of vimentin, a major component of intermediate filaments, showed an opposite behaviour since the suspension culture enhances the accumulation of both vimentin and its mRNAs. Therefore in chick embryo cultured chondrocytes and in vivo, during cartilage development, cell shape changes and/or integrin-extracellular matrix protein interactions may be involved in the regulation of these two genes coding for cytoskeletal proteins.

Microbial metabolism of fluazifop-butyl

A microbial mixed culture able to grow on fluazifop-butyl and fluazifop was isolated. Fluazifop degradation by this microbial population was studied either when the herbicide was applied as the sole carbon source or in the presence of a second carbon source (sodium acetate or sodium propionate). The degradation rate was enhanced by sodium propionate. The degradation was found to be stereoselective. The S-enantiomer of fluazifop was degraded at a much higher rate than the R-enantiomer. Fluazifop disappearance was accompanied by formation of three metabolites which were identified by UV, IR, MS and NMR analyses. The metabolites were shown to be: 4-(5-trifluoromethyl-2-pyridyl)oxyphenol, 5-trifluoromethyl-2- hydroxypyridine and 2-(5-trifluoro-methyl pyridyl)hydroxy acetate.

Type XIV collagen is encoded by alternative transcripts with distinct 5' regions and is a multidomain protein with homologies to von Willebrand's factor, fibronectin, and other matrix proteins

The combined nucleotide sequences of several overlapping cDNAs provide the first complete amino acid sequence of type XIV collagen. Independent confirmation of the deduced sequence is provided by amino acid sequencing of several tryptic peptides isolated from purified chicken skin type XIV collagen. Comparative analyses show that the amino-terminal non-triple-helical region of alpha 1(XIV) chains contains sequence motifs that are similar to alpha 1(IX) collagen, fibronectin type III repeats, and von Willebrand's factor A-domains. The results also strongly suggest that the alpha 1(XIV) collagen gene is identical to the gene encoding the matrix component previously named undulin. cDNAs covering the 5' region of alpha 1(XIV) mRNA fall into two classes with distinct sequences in their 5'-untranslated regions. We believe the two alternative sequences result from differential splicing of the primary transcript. Interestingly, one of the untranslated sequences shows a high degree of identity with the cis-regulatory translational control sequence in the 5'-untranslated region of a Drosophila ribosomal protein mRNA. We hypothesize therefore that the sequence in alpha 1(XIV) collagen may play a role in the control of alpha 1(XIV) protein synthesis.

A study of the incidence of different fluorescent Pseudomonas species and biovars in the microflora of fresh and spoiled meat and fish, raw milk, cheese, soil and water

Of 182 various foodstuffs and environmental samples examined, 86% had microflora containing fluorescent Pseudomonas in differing proportions. A computer-aided technique was used to identify most of the 445 fluorescent strains. Pseudomonas fluorescens biovar V-1 was most frequently isolated (24%); it either predominated or was present in all types of samples. Other strains, belonging to the other subgroups of biovar V (V-2, V-4, V-5, V-6 and V-7), together represented 14.3%. We also identified Ps. fluorescens biovars I-1 and I-2 (13.9%), II-1 and II-3 (3.6%), III-1 and III-2 (8.7%), IV-2 (0.7%); Ps. putida A and B (11%); Ps. lundensis (10.3%); group B3 (2%) and Ps. aeruginosa (0.7%). Unidentified strains accounted for 10.6% of the flora, many resembling Ps. fluorescens biovar V. Although the presence of Ps. fluorescens V-1 was often marked, other taxa predominated or were present in large quantities in some particular samples, such as Ps. fluorescens I-1 in raw milk and cheese, Ps. lundensis in spoiled meat and Ps. fluorescens III-1 in spoiled fish. Pseudomonas putida A and B were evident in environmental rather than in food samples.

Glutathione is the antioxidant responsible for resistance to oxidative stress in V79 Chinese hamster fibroblasts rendered resistant to cadmium

By manipulation of Cd and Zn concentrations in the medium, several phenotypes, differing in the contents of glutathione (GSH) and metallothionein (Mt), were derived from a parental clone of V79 Chinese hamster fibroblast. In some of these phenotypes, resistance to Cd and cross-resistance to oxidative stress was developed. The highest levels of GSH and Mt were found in cells which were rendered resistant to Cd by stepwise increases of Cd and Zn in the cell medium for over 50 passages. Upon removal of Cd/Zn from the medium of these cells or addition of Cd/Zn to the parental cell medium, changes of cellular GSH and Mt levels occurred to different extents. At the same time, changes in the resistance to Cd and H2O2 were observed. Good linear correlations were observed for Mt levels x resistance to Cd and for GSH levels x resistance to H2O2. Poor linear correlations were found for Mt levels x resistance to H2O2 or for GSH levels x resistance to Cd. Moreover, addition of Zn to the medium produced an increase in Mt content without affecting the GSH content. In this case no cross-resistance to oxidative stress was developed. Therefore, Mt which has been shown to be an excellent antioxidant in in vitro experiments, does not seem to play any major role against oxidative stress in Zn and Cd challenged cells. Most of the cross-resistance to oxidative stress in Cd challenged cells seems to be accounted for by the parallel increase in GSH.

Isolation and characterization by conventional methods and genetic transformation of Psychrobacter and Acinetobacter from fresh and spoiled meat, milk and cheese

Of 126 samples of fresh and spoiled meat and dairy products, 40% were positive for the presence of Moraxella-like bacteria and 64% of Acinetobacter; 279 and 466 strains, respectively, were isolated and a part of these were tested by biochemical methods and DNA transformation assays. In some cases, the Moraxellaceae in the samples examined reached considerable quantitative levels, but their percentage in the microflora was generally low. Moraxella-like bacteria were predominant in fresh meat, Acinetobacter in spoiled meat and milk. Most acinetobacters belonged to biotype lwoffii (sensu lato) and all 90 strains tested were positive for DNA transformation with an auxotrophic Acinetobacter. Moraxella-like bacteria were identified as Psychrobacter immobilis in 96% of 103 transformation assays. Moraxellaceae show lipolytic activity but they are considered of low incidence in food spoilage. Only 3.7% of acinetobacters from dairy sources was able to produce ropy milk. Unlike strains from clinical isolates, psychrobacters and acinetobacters isolated from food often do not grow at 37 degrees C.

cDNA cloning and gene expression of chicken osteopontin. Expression of osteopontin mRNA in chondrocytes is enhanced by trypsin treatment of cells

A cDNA clone, pCP15, specific for the chicken 66-kDa major bone phosphoprotein (osteopontin), was isolated from a subtracted library enriched in DNAs coding for mRNAs expressed in chicken differentiating chondrocytes. Northern blot analysis of RNAs extracted from several chick embryo tissues and organs, confirm and extend the observation that osteopontin mRNA expression is not restricted to tissues involved in phosphate metabolism. Osteopontin mRNA was detected in sternal resting chondrocytes at higher levels than in hypertrophic chondrocytes; therefore osteopontin gene transcription occurs in chondrocytes at many stages of differentiation. The steady state level of osteopontin mRNA was enhanced by trypsin treatment of cultured cells. An increased level of osteopontin mRNA in quail chondrocytes constitutively expressing v-myc oncogene is also shown.

[The aging of the heart: weight and structural changes in the left ventricle with age]

Structural alterations of the cardiovascular system with aging are difficult to differentiate from superimposed pathologic processes. To determine whether aging "per se" affects the dimension of the heart, the weight of the heart, and the left ventricle and their rations to body weight, left ventricle wall thickness, the number of myocyte nuclei in the ventricle and the myocyte cell volume per nucleus were measured in 67 autopsies of subjects, 45 males and 22 females, who died from causes independent of cardiovascular diseases, from 17 to 90 years old. With aging, total heart weight increased slightly, while left ventricular and interventricular septum weights after dissection of the subepicardial fat decreased significantly (r = 0.44; p less than 0.001). Although left ventricular wall thickness remained constant with time, left ventricular weight to body weight ratio decreased progressively. At the structural level the number of myocyte nuclei within the left ventricle decreased (r = 0.45; p less than 0.001), whereas myocyte cell volume per nucleus increased (r = 0.30; p greater than 0.05) with age. Thus, the aging process of the heart is associated with a reduction in volume of the myocardial mass resulting from myocyte cell loss and reactive hypertrophy of the spared myocytes.

Liquid chromatographic determination of acifluorfen in soil and water

An analytical method based on the use of a liquid chromatograph equipped with a UV detector was developed for the determination of acifluorfen in soil and water. Acifluorfen was extracted from soil in methanol-0.10N NaOH (80 + 20 v/v) and from water by partition with dichloromethane. Solvent partitioning and solid-phase extraction were used to separate acifluorfen from major interfering sample components. Average recoveries from soil at 1, 0.1, and 0.01 ppm fortification levels were 95.1 +/- 3.4, 92.6 +/- 2.9, and 73.9 +/- 3.0%, respectively. Recoveries from water spiked at levels from 0.01 to 1 ppm averaged 96.5 +/- 5.4%. Method limits of detection were 0.006 ppm in soil and 0.003 ppm in water.

Prevention of non-hemolytic transfusion reactions with leucocyte-poor blood: a prospective study

Twenty-five patients with homozygous beta-thalassemia, who complained of occasional nonhemolytic transfusion reactions (NHTR), were alternately transfused eight times with normal packed red cells (PRC) and leucocyte-poor blood prepared by three methods: cotton wool filtration (CWF), buffy coat removal after dilution with saline and upright spin (BCR), and microaggregate filtration (MAF). On overall, CWF-treated RBC concentrates (CWF-RBC) contained 0.02 x 10(9) leucocytes; BCR-RBC contained 0.4 x 10(9), MAF-RBC 1.3 x 10(9) and PRC 1.7 x 10(9). The frequencies of NHTR were: CWF, 0.02; BCR, 0.04; MAF, 0.20; PRC, 0.28. Compared to PRC, both CWF and BCR significantly reduced the frequency of NHTR (p less than 0.01), whilst MAF did not (p greater than 0.1). On the other hand, in one patient CWF caused the two most severe NHTR recorded in this study, both of which were characterized by anaphylaxis.

Multiple splanchnic artery aneurysms. Report of a case

It is reported the case of a patient with multiple visceral aneurysms (seven). These aneurysms are more common than usually appreciated but their multiplicity is rarely reported in the literature. Angiography should always follow surgery when a splanchnic aneurysm is recognized by chance only at operation and when the surgeon is already aware of the multiple aneurysms. It is indicated a contemporary treatment of all of them to avoid the subsequent risk of rupture which has been suggested to increase after laparotomy.