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Summary: Background: Trema micrantha is a tree widely distributed throughout the Americas. The tree produces highly palatable leaves that have been associated with natural poisoning in goats, sheep and horses, in which hepatic necrosis and hepatic encephalopathy have been observed. Objectives: This study describes malacia and haemorrhage in the central nervous system (CNS) due to T. micrantha consumption, with minimal to absent hepatic lesions. Study design: Retrospective case series. Methods: A total of 14 horses with a history of neurological signs and spontaneous consumption of T. micrantha leaves were submitted to necropsy and multiple samples were collected for histopathology. Details of clinical history and signs of the horses were obtained through inquiries to the owners and attending veterinarians. Results: All the 14 horses had neurological signs of ataxia, severe sialorrhoea, involuntary running movements, sternal and lateral recumbency, and death after a clinical course that lasted from 24 h to 9 days. For a few days prior to onset of clinical signs, all horses had spontaneously consumed, potentially toxic doses of T. micrantha leaves. All 14 brains had diffuse yellowish discoloration affecting the rhombencephalon, mesencephalon, diencephalon, telencephalon and corpus striatum. In all cases, the most severe lesions were observed in the pons. Spinal cord lesions were observed affecting the lumbar intumescence, which was swollen with darken and depressed areas at the dorsal and ventral horns, and at the sacral level, which on cut surface displayed a friable and yellowish grey matter. The lesions observed grossly in brain and spinal cord consisted microscopically of severe vasculitis and liquefactive necrosis of white and grey matter of the brainstem, cerebellum and spinal cord. Main limitations: This is a small retrospective series relying on clinical observations reported by owners and attending veterinarians. The mechanism of action of the plant toxin in the CNS is still unidentified. Conclusion: T. micrantha poisoning in horses causes predominantly a neurological disease, with minimal to absent hepatic lesions. [ABSTRACT FROM AUTHOR]

The ecological knowledge of large rivers is still scarce or highly fragmented mainly because of complex, laborious and expensive procedures to collect informative samples from the benthic biota. Standard sampling protocols for macroinvertebrates were mainly developed and calibrated for wadeable streams, while a number of heterogeneous non-standard sampling procedures are available for large rivers. We propose the new, easy-to-build and cost-effective leaf-nets (LN) method to quantitatively sample benthic invertebrates in non-wadeable waterways. The LN method uses Phragmites australis leaves as substrate and combines the characteristics of the leaf-bags and the Hester-Dendy (HD) multiplates methods. We compared the effectiveness of the LN and HD methods in a near-pristine and in an impacted stream-reach (downstream an aquaculture plant) of a non-wadeable second-order stream of Central Apennines (Italy). Twenty-five of the 34 cumulatively collected macroinvertebrate taxa were common to both methods, while seven taxa were found only on LN and two only on HD. Taxonomic richness and total macroinvertebrate abundance were higher for LN assemblages. Number of Ephemeroptera, Plecoptera and Trichoptera taxa (EPT) also tended to be higher on LN. Assemblage composition was different on LN and HD. Both methods documented a significant decrease in EPT taxa and a concomitant increase in the total abundance of more pollution-tolerant taxa in the impacted stream-reach, but the LN method was more sensitive to impact-associated changes in macroinvertebrate assemblage structure. In contrast to the hardboard plates of HD, the assembled leaves of the LN may act as a direct or indirect food source and may better mimic the texture and composition of more heterogeneous natural substrates thus favouring the migration-colonization process from both bottom and littoral benthic invertebrates. The sampling efficiency, cost effectiveness and simplicity warrant the routine use of the new LN method in large-river ecological assessment. Copyright © 2015 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

Circadian and ultradian rhythms were analyzed in Sabella spallanzanii tested in laboratory constant darkness conditions. A video camera took images per 30 s during a week. The number of times animals opened the fan per 30 min was counted by an observer. Resulting time series were subdivided into 24-h segments in order to assess the change of the activity rhythm over consecutive days. Periodogram and waveform analyses measured the periodicity and the pattern of fluctuation, at each cycle. Results indicate that animals express a major circadian peak in the first day of test, and this progressively spits into subcomponents from days 2 to 4. At days 5 and 6 the circadian peak is reconstituted. The activity phase of a rhythm (α) and its amplitude of oscillation were also computed per 24-h segments. The values of different time series were averaged at corresponding 24-h stages. A significant increment of mean α was observed from days 1 to 4, while conversely the amplitude decreased. From days 5 to day 6, an opposite trend in both variables was observed. These results are descriptive but can be interpreted in the context of models accounting for the generation of ultradian rhythms when controlling oscillators became transiently uncoupled. [ABSTRACT FROM AUTHOR]

We evaluated the analytical characteristics and clinical usefulness of a commercial immunoradiometric assay (IRMA) kit for brain natriuretic peptide (BNP). Mean (±SD) plasma BNP concentrations measured in 129 normal subjects were 2.9±2.7 pmol/l (median 2.2 pmol/l; range 0.1-12.4 pmol/l). The mean (±SD) value observed in healthy men (2.1±2.0 pmol/l, n=49) was significantly (p=0.0009) different to that found in women (3.4±2.9 pmol/l, n=80). A positive relationship (R=0.214, p=0.0174) was found between BNP values and age. In 65 patients with cardiac diseases, BNP levels increased with the progression of clinical severity of disease; patients with more severe disease [NYHA functional class III-IV, mean (±SD) BNP=254±408 pmol/l, n=22] showed significantly (p<0.0001) increased values compared to patients with mild symptoms of disease (NYHA functional class I-II, mean (±SD) BNP=19.6±17.2 pmol/l, n=43). Furthermore, in 32 patients with chronic renal failure, greatly increased (p<0.0001) BNP values were found both before (mean±SD=88.1±111.1 pmol/l) and after haemodialysis (mean±SD=65.6±76.7 pmol/l), with a significant reduction after haemodialysis (p=0.0004) compared to pre-haemodialysis. The mean (±SD) BNP value found in atrial extracts collected during aorto-coronary bypass operations in 15 patients was 14.5±51.9 pmol/g of cardiac tissue. Moreover, the mean (±SD) tissue levels of BNP in 7 heart transplant recipients were 128.4±117.2 pmol/g of cardiac tissue in atrium, 68.4±76.7 pmol/g in ventricle, and 10.9±8.5 pmol/g in interventricular septum. Finally, BNP values found in cardiac tissues of two subjects collected at autopsy were considerably lower (on average 1/1000) than those observed in cardiac tissues of patients with cardiac diseases. The IRMA method for BNP determination evaluated in this study showed a good degree of sensitivity, precision and practicability. Therefore, this method should be a reliable tool for the measurement of plasma BNP levels for both experimental studies and routine assay. [ABSTRACT FROM AUTHOR]

A method involving the use of an energy-dispersive X-ray fluorescence spectrometer was developed for assaying total platinum concentrations in body fluids of patients treated with the antitumor drug cis-dichlorodiammineplatinum(II). Sample preparation by this procedure is simple, consisting in adding an internal standard (Zr) to 1 ml of biological fluid or tissue homogenate, pipetting 20 microliter of the sample onto a Mylar sample holder, and drying. This produces a thin-film sample, which effectively eliminates absorption enhancement effects due to other elements in the specimen. Standard addition studies were found to be linear in the concentration range of interest (0.1-10.0 micrograms/ml), with correlation coefficients exceeding 0.99. Minimum detection limits range from 0.10 to 0.25 micrograms Pt per ml, depending on the body fluid, which is adequate for routine patient monitoring after normal chemotherapeutic doses of cis-dichlorodiammineplatinum(II). In preliminary studies with mammalian liver, standard addition experiments were found to be linear and the minimum detection limit was found to be 1.4 micrograms/g dry weight. [ABSTRACT FROM AUTHOR]

Using X-ray fluorescence spectrometry, platinum concentrations were determined in autopsy tissue samples from 12 patients who had received cis-diamminedichloroplatinum (DDP) 20-120 mg/m2 up to 6 months antemortem. Tissue platinum concentrations were highest in liver (0.5-3.7 micrograms/g wet weight), prostate (1.6-3.6 micrograms/g), and kidney (0.4-2.9 micrograms/g), somewhat lower in bladder, muscle, testicle, pancreas, and spleen, and lowest in bowel, adrenal, heart, lung, cerebrum, and cerebellum, Platinum concentrations in tumors were generally somewhat lower than the concentration in the organ in which the tumor was located, with the exception of intracerebral tumors. Different metastatic sites in the same patient had substantially different platinum concentrations and hepatic metastases had the highest concentrations. Intra-arterial administration of drug may augment tissue concentrations of platinum. In a patient undergoing therapeutic abortion 4 days after treatment, the platinum concentration was 0.5 micrograms/g in the placenta and 0.3 micrograms/g in the fetus. The data suggest that for in vitro sensitivity testing, DDP concentrations of less than or equal to 7 micrograms/ml should be used. [ABSTRACT FROM AUTHOR]

The metastable ions [M]2+, [M - H]2+· and [M - H2]2+ from malononitrile fragment by loss of [CH]+, [C]+· and [C]+·, respectively. The reaction of the molecular ion involves the methylene and nitrile carbon atoms in the statistical probability ratio, while that of [M - H]2+· involves exclusively the nitrile carbon and that of [M  H2]2+ involves an approximately equal contribution, from both sources. It is suggested that the metastable molecular ion fragments through a bipyrimidal intermediate. [ABSTRACT FROM AUTHOR]

The structures of reactive and nonreactive ions formed by McLafferty rearrangement in a variety of ketones are studied using metastable ion abundances and the kinetic energy released in metastable ion fragmentations. The loss of methyl radicals is studied in [C5H10O]+. ions and the mechanism delineated for ions formed in an initial configuration corresponding both to ketonic and enolic forms; the major mechanism in both cases appears to involve a common intermediate. Partial scrambling of hydrogen atoms on the C-1 and C-5 carbons and on the oxygen precedes methyl elimination. Loss of neutral ethylene from [C5H10O]+. ions is also studied and again the major mechanism occurs via a common species, intermediate in structure between a ketone and an enol; scrambling of hydrogen is much faster for ions that lose ethylene than for those which lose a methyl radical. Keto ions of formula [C3H6O]+. show no unimolecular loss of methyl. The stable [C3H6O]+. ions generated in the keto and enol forms are shown to preserve their initial structures, confirming the results of ion cyclotron resonance experiments. Reactive [C3H6O]+. ions formed from 2-pentanone molecular ions by McLafferty rearrangement are shown to have the same structures as reactive ions originally generated as enolic structures from 1-methylcyclobutanol. The paper highlights the relationship between hydrogen scrambling and keto-enol isomerization reactions in aliphatic ketones. [ABSTRACT FROM AUTHOR]

The molecular ion of benzyl benzoate undergoes several decompositions, two of which are the loss of H 2O and COOH·. To study these processes, the mass and IKE spectra of benzyl benzoate together with various deuterated benzyl benzoates and some of its isomers were studied. Evidence is presented to support the rearrangement processes of the molecular ion. A decomposition scheme is proposed to explain the observed transitions. [ABSTRACT FROM AUTHOR]

The ion kinetic energy (IKE) spectra of pyrazine, pyrimidine, pyridazine, pyrazine- d4, pyrimidine- d4 and pyridazine- d4 have shown that these compounds can more readily be distinguished on the basis of IKE spectra than mass spectra. Studies of the fragmentation of various doublycharged ions have given information about the localization of charge on the heteroatoms and on the structures of the ions themselves. Transition states from which fragmentation occurs for doublycharged ions with loss of either [H]+ or [D]+ have shown large differences of the order 1 Å between the intercharge distances in the two cases. [ABSTRACT FROM AUTHOR]

A series of alkylphenylketones has been examined. Whenever the alkyl chain is three or more carbon atoms long, the well-known McLafferty rearrangement occurs with elimination of the elements of a neutral olefin. The further fragmentation of the ion formed in this rearrangement reaction has been studied using the technique of ion kinetic energy (IKE) spectroscopy. The measured release of kinetic energy has been used to show that the rearrangement ion has an enolic type structure. [ABSTRACT FROM AUTHOR]

The ion kinetic energy (IKE) spectra of nonan-4-one, 7,7-d2-nonan-4-one and 1,1,1-d3-nonan-4-one have been recorded and interpreted. The various fragmentations observed in the IKE spectra have been confirmed and some new fragmentations found by carrying out high voltage scans with the magnetic field set successively to collect ions at each mass to charge ratio throughout the mass spectrum. Several new fragmentation modes have been discovered, and their significance is discussed. [ABSTRACT FROM AUTHOR]

The ion kinetic energy spectra of o-, m-and p-phenylendiamine are presented. Decompositions of doubly-charged ions are given for the three isomers. From the width of the peaks, the energy released is measured and the equivalent intercharge distance is calculated. The results are discussed in terms of possible structures of the various ions. Also, metastable transitions which could give rise to peaks corresponding to energies below that of the mainion beam are listed and the results discussed. Significant differences were observed among the energy spectra of the three isomers. [ABSTRACT FROM AUTHOR]

Studies have been made of the energy release during the decomposition of metastable ions in the mass spectra of pyrazine, pyrazine-d4, pyrimidine, pyrimidine-d4, pyridazine and symmtriazine. In all the compounds except pyridazine very small amounts of energy have been measured in some processes. The recorded energy release of 187 μeV for a transition of the symmtriazine molecular ion is the smallest energy release yet recorded. In the case of pyrazine and pyrimidine the energy release in one transition was found to be smaller than in the corresponding transition in the -d4 analogues. [ABSTRACT FROM AUTHOR]