Taxonomic units, civilization, volcanism: Their influence on the chemical composition of ostracod carapaces (Kagoshima Bay, Kyushu Island, Japan)

To test the influence of both civilization and volcanism on the chemical composition of ostracod carapaces, 32 well-preserved valves from Kagoshima Bay (Kyushu Island, South Japan) were analysed by means of spark source mass spectrometry. In Kagoshima Bay, the extent of pollution corresponds to human activities. Kagoshima Bay is also an area of important volcanic activity: emissions from Sakurajima volcano are very frequent. The species analysed were Argilloecia hanaii, Callistocythere undulatifacialis, Pontocythere subjaponica and Loxoconcha tosaensis. Twenty-three chemical elements were detected. Among them, 11 were always above the limit of detection: Al, B, Cl, F, Fe, K, Na, P, S, Si and Zn. The correlation between Zn and Fe was characteristic of the volcanic environment. Two discriminant analyses were performed using either the location area or the species as grouping variables. An association between Zn and S is possible; it could be related to volcanic activity. The chemical composition of carapaces is ascribed to taxonomic units rather than the environment.     

Surface photochemistry: benzophenone as a probe for the study of silica and reversed-phase silica surfaces.

This work reports the use of benzophenone, a very well characterized probe, to study new hosts: two reversed-phase silicas. Laser-induced room temperature luminescence of argon purged solid powdered samples of benzophenone adsorbed onto the two different reversed-phase silicas, RP-18 and RP-8, revealed the existence of a low energy emission band in contrast with the benzophenone adsorbed on 60 A pore silica, where only triplet benzophenone emits. This low energy emission band was identified as the fluorescence of the ketyl radical of benzophenone, which is formed as the result of a hydrogen atom abstraction reaction of the triplet excited benzophenone from the alkyl groups of the surface of the reversed silicas. Such emission does not exist for benzophenone adsorbed onto 60 A pore silica. Room temperature phosphorescence was obtained in argon purged samples for all the surfaces under use. The decay times of the benzophenone emission vary greatly with the alkylation of the silica surface when compared with "normal" silica surface. A lifetime distributions analysis has shown that the shortest lifetimes for the benzophenone emission exist in the former case. Triplet-triplet absorption of benzophenone was detected in all cases and is the predominant absorption in the case of 60 A pore silica, while benzophenone ketyl radical formation occurs in the case of the reversed silicas. Diffuse reflectance laser flash photolysis and gas chromatography-mass spectrometry techniques provided complementary information, the former about transient species and the latter regarding the final products formed after laser irradiation, both at 266 nm or 355 nm. Product analysis and identification show that the degradation photoproducts are dependent on the excitation wavelength, the photochemistry being much more rich and complex in the 266 nm excitation case, where an alpha-cleavage reaction occurs. A detailed mechanistic analysis is proposed.     

Kinesigenic paroxysmal hemidyskinesia as the initial presentation of multiple sclerosis

Fewer than a hundred cases of paroxysmal dystonia have been described in patients with multiple sclerosis (MS). Even fewer cases of hemidyskinesia triggered by repetitive movements (paroxysmal kinesigenic hemidyskinesia--PKD) have been reported in MS patients. We describe the case of a woman, age 18 years at the onset of MS, and a man age 35 years at the onset of MS, who presented with PKD as the initial symptom. Magnetic resonance images (MRI) of these patients showed different areas of acute lesions possibly related to PKD; MRI of one of the patients demonstrated 1 lesion in the subcortical parietal area and another in the thalamic region and showed 2 lesions in the cervical spinal cord in the other patient.     

Degradation of naphthenic acids by sediment micro-organisms

AIMS: Naphthenic acids (NAs) are naturally occurring, linear and cyclic carboxylic surfactants associated with the acidic fraction of petroleum. NAs account for most of the acute aquatic toxicity of oil sands process-affected water (OSPW). The toxicity of OSPW can be reduced by microbial degradation. The aim of this research was to determine the extent of NA degradation by sediment microbial communities exposed to varying amounts of OSPW. METHODS AND RESULTS: Eleven wetlands, both natural and process-affected, and one tailings settling pond in Northern Alberta were studied. The natural wetlands and process-affected sites fell into two distinct groups based on their water chemistry. The extent of degradation of a 14C-labelled monocyclic NA surrogate [14C-cyclohexane carboxylic acid (CCA)] was relatively uniform in all sediments (approximately 30%) after 14 days. In contrast, degradation of a bicyclic NA surrogate [14C-decahydronaphthoic acid (DHNA)] was significantly lower in non process-affected sediments. Enrichment cultures, obtained from an active tailings settling pond, using commercially available NAs as the sole carbon source, resulted in the isolation of a co-culture containing Pseudomonas putida and Pseudomonas fluorescens. Quantitative GC-MS analysis showed that the co-culture removed >95% of the commercial NAs, and partially degraded the process NAs from OSPW with a resulting NA profile similar to that from 'aged wetlands'. CONCLUSIONS: Exposure to NAs induced and/or selected micro-organisms capable of more effectively degrading bicyclic NAs. Native Pseudomonas spp. extensively degraded fresh, commercial NA. The recalcitrant NAs resembled those found in process-affected wetlands. SIGNIFICANCE AND IMPACT OF THE STUDY: These results suggest that it may be possible to manipulate the existing environmental conditions to select for a microbial community exhibiting higher rates of NA degradation. This will have significant impact on the design of artificial wetlands for water treatment.     

Predictors of development of cardiac and digestive disorders among patients with indeterminate chronic Chagas Disease

American trypanosomiasis (Chagas disease, CD) affects circa 7 million persons worldwide. While of those persons present the asymptomatic, indeterminate chronic form (ICF), many will eventually progress to cardiac or digestive disorders. We studied a nonconcurrent (retrospective) cohort of patients attending an outpatient CD clinic in Southeastern Brazil, who were admitted while presenting the ICF in the period from 1998 through 2018 and followed until 2019. The outcomes of interest were the progression to cardiac or digestive CD forms. We were also interested in analyzing the impact of Benznidazole therapy on the progression of the disease. Extensive review of medical charts and laboratory files was conducted, collecting data up to year 2019. Demographics (upon inclusion), body mass index, comorbidities (including the Charlson index) and use of Benznidazole were recorded. The outcomes were defined by abnormalities in those test that could not be attributed to other causes. Statistical analysis included univariate and multivariable Cox regression models. Among 379 subjects included in the study, 87 (22.9%) and 100 (26.4%) progressed to cardiac and digestive forms, respectively. In the final multivariable model, cardiac disorders were positively associated with previous coronary syndrome (Hazzard Ratio [HR], 2.42; 95% Confidence Interval [CI], 1.53–3.81) and negatively associated with Benznidazole therapy (HR, 0.26; 95%CI, 0.11–0.60). On the other hand, female gender was the only independent predictor of progression to digestive forms (HR, 1.56; 95%CI, 1.03–2.38). Our results point to the impact of comorbidities on progression do cardiac CD, with possible benefit of the use of Benznidazole.     

Test, rejection, and reformulation of a chemical reactor-based model of gut function in a fruit-eating bird

We explored modulation of retention time in cedar waxwings (Bombycilla cedrorum) by feeding them diets varying in hexose concentration. Our goals were to (1) test three predictions of a chemical reactor-based model of how guts might respond optimally to diet shifts; (2) determine whether modulation of retention time can occur quickly, thereby facilitating rapid changes in diet; (3) tease apart the relative influence of ingestion rate and nutrient concentration on retention time; and (4) examine the degree of axial mixing in the intestine and its relationship with retention time. The model's predictions were rejected: mean retention time did not decrease, ingestion rate did not increase, and glucose assimilation efficiency did not decrease with increased hexose concentration of the diet. Instead, birds displayed maximal intake rate at intermediate sugar concentration, and mouth to cloaca mean retention times increased with hexose concentration. Significant modulation of retention time occurred quickly, within 3 h of exposure to a different diet. Birds did equally well in terms of total energy assimilated on diets differing 3.3-fold in hexose concentration (from 500 mmol/L to 1660 mmol/L) but showed reduced intake when fed food with low hexose concentration (110 mmol/L). Far more variation in retention time was explained by direct effects of ingestion rate than by direct effects of hexose concentration. Finally, a gut dispersion index that measured degree of axial mixing was positively correlated with mean retention time, indicating that higher retention times are accompanied by increased axial mixing. We propose a modification of the assumptions of the original model. The resulting "osmotic constraint" model better captures the interaction between feeding rate and digestive function in fruit-eating birds.     

Changes in several functions of murine peritoneal macrophages by N-acetylcysteine and thioproline ingestion. Comparative effect between two strains of mice

The administration of the thiol compounds, N-acetylcysteine (NAC) and in particular thioproline (thiazolidine-4-carboxylic acid) at 0.1% w/w concentration in the diet, improves lymphocyte functions in old female Swiss mice, as has been shown in our previous studies. In the present work, adult mice from two different strains, namely BALB/c (an inbred strain) and OF1-Swiss (noninbred strain), were fed a diet supplemented with the above dose of each thiol compound jointly for five weeks. At 28 weeks of age, peritoneal cell suspensions were obtained and different steps of the phagocytic process, the most representative activity of macrophages, as well as interleukin-1beta (IL-1beta) production, were studied. Thus, adherence to substrate, mobility directed to a chemoattractant gradient (chemotaxis), ingestion of inert particles and superoxide anion production were analysed. The results show that diet supplementation with NAC plus thioproline increased all macrophage functions studied with the exception of superoxide anion production, which was decreased. These effects were more evident in macrophages from Swiss mice, whereas in BALB/c mice the stimulation of phagocytosis and IL-1beta production was lower and no differences were seen after treatment in adherence and superoxide anion production. These data suggest that immune function can be improved in adult mice by administration of the above thiol compounds, especially in the noninbred strain of OF1-Swiss mice.     

The Activities of Six Exo- and Endopeptidases in the Substantia Nigra,Neostriatum, and Cortex of the Rat Brain

We determined the enzymatic activity and crude subcellular distribution of four exopeptidases: Dipeptidylaminopeptidase IV (DAP-IV), Alanyl aminopeptidase (AAP), Prolyl aminopeptidase (PAP) and -Glutamyl transpeptidase (GTP), and two endopeptidases: Postproline endopeptidase (PEP) and Trypsin-like peptidase (T-L P) in pars compacta (SNPC) and pars reticulata (SNPR) of substantia nigra, caudate-putamen (CAU) and cerebral cortex (CC) of the rat brain. We found: 1) DAP-IV activity is comparatively higher in SNPC and it is equally distributed in the postmitochondrial precipitate (PR) and supernatant (SN) fractions of SNPC, CAU and CC but higher in the SN from SNPR. 2) CC shows the highest activity of AAP and its activity is mainly located in the SN from all areas. 3) The activity of PAP is comparatively higher in SNPC and it is exclusively located in the SN from all areas. 4) GTP activity is similar in all areas but its predominance is in the SN for SNPC and SNPR, and in the PR for CAU and CC. 5) CAU has higher PEP activity (higher in the PR) than CC (higher in the SN); no activity is detected in the substantia nigra. 6) The activity of a Trypsin-like peptidase is the highest in SNPC and SNPR; this activity have some predominance in the SN and higher predominance in the same fraction from CAU and CC.     

Extensive Genetic Polymorphism of Peptidases A, B, C, and D, in Wild Rabbit (Oryctolagus cuniculus) Populations from the Iberian Peninsula

Genetic polymorphism of peptidases A, B, C, andD in the wild rabbit (Oryctolagus cuniculus)was assessed by horizontal starch gel electrophoresis,in a total of 1003 individuals comprising 16 Iberian and 2 French populations and 1 domestic stock.Twenty-five different alleles were detected: 6 in PEPA,4 in PEPB, 8 in PEPC, and 7 in PEPD. The highest valuesof observed heterozygosity averaged over the four loci were obtained for the southwestern Iberianpopulations and a clinal loss of variability in anortheastern direction was detected. A clear separationbetween the two putative subspecies O. c.cuniculus and O. c. algirus was notobtained.