Variation in the carotenoid composition of acerola and its processed products

Acerola is now commercially produced and processed in Brazil. Known for its very high vitamin C content, this fruit is also a good source of β‐carotene. The present study was carried out to verify variation in the carotenoid composition along the food chain. Neoxanthin, violaxanthin, lutein, β‐cryptoxanthin, α‐carotene and β‐carotene were found in the acerola fruit. β‐Carotene predominated with mean concentrations of 12.4 and 38.1 µg g^?1 in the ripe fruit, 8.8 and 30.1 µg g^?1 in the peeled ripe fruit and 5.4 and 12.0 µg g^?1 in the partially ripe fruit of an undefined variety taken from home gardens and the commercial cultivar Olivier, respectively. Aside from β‐carotene, β‐cryptoxanthin increased significantly in both garden and commercial fruits and violaxanthin in the latter fruits during ripening. Peeling reduced β‐carotene in both garden and commercial lots, violaxanthin decreased in the commercial fruits, and the other carotenoids remained virtually unchanged. Four brands of frozen pulp and three brands of processed juice had variable and markedly lower carotenoid levels than those of the fresh fruit, indicating that the processing should be improved. Copyright © 2006 Society of Chemical Industry     

Photoelectrocatalytic determination of NADH in a flow injection system with electropolymerized methylene blue

It was firstly described that a glassy carbon electrode electropolymerized with methylene blue shows an efficient photoelectrocatalytic activity towards NADH oxidation in a phosphate buffer solution (pH 7.0). In order to perform the photoelectrocatalytic determination of NADH in a flow injection analysis (FIA) system, a home-made flow electrochemical cell with a suitable transparent window for the irradiation of the electrode surface was constructed. The currents obtained from the photoamperometric measurements in the FIA system at optimum conditions (flow rate of carrier solution, 1.3 mL min⁻¹; transmission tubing length, 10 cm; injection volume, 100 μL; and constant applied potential, +150 mV vs. Ag/AgCl) were linearly dependent on the NADH concentration and linear calibration curves were obtained in the range of 1.0 × 10⁻⁷–2.0 × 10⁻⁴ M. The detection limit was found to be 4.0 × 10⁻⁸ M for photoamperometric determination of NADH.     

Kinetics of para-nitrophenol and chemical oxygen demand removal from synthetic wastewater in an anaerobic migrating blanket reactor

A laboratory scale anaerobic migrating blanket reactor (AMBR) was operated at different HRTs (1-10.38 days) in order to determine the para-nitrophenol (p-NP) and COD removal kinetic constants. The reactor was fed with 40 mg L(-1)p-NP and 3000 mg L(-1) glucose-COD. Modified Stover-Kincannon and Grau second-order kinetic models were applied to the experimental data. The predicted p-NP and COD concentrations were calculated using the kinetic constants. It was found that these data were in better agreement with the observed ones in the modified Stover-Kincannon compared to Grau second-order model. The kinetic constants calculated according to Stover-Kincannon model are as follows: the saturation value constant (K(B)) and maximum utilization rate constants (R(max)) were found as 31.55 g CODL(-1)day(-1), 29.49 g CODL(-1)day(-1) for COD removal and 0.428 g p-NPL(-1)day(-1), 0.407 g p-NPL(-1)day(-1) for p-NP removal, respectively (R(2)=1). The values of (a) and (b) were found to be 0.096 day and 1.071 (dimensionless) with high correlation coefficients of R(2)=0.85 for COD removal. Kinetic constants for specific gas production rate were evaluated using modified Stover-Kincannon, Van der Meer and Heerrtjes and Chen and Hasminoto models. It was shown that Stover-Kincannon model is more appropriate for calculating the effluent COD, p-NP concentrations in AMBR compared to the other models. The maximum specific biogas production rate, G(max), and proportionality constant, G(B), were found to be 1666.7 mL L(-1) day(-1) and 2.83 (dimensionless), respectively in modified Stover-Kincannon gas model. The bacteria had low Haldane inhibition constants (K(ID)=14 and 23 mg L(-1)) for p-NP concentrations higher than 40 mg L(-1) while the half velocity constant (K(s)) increased from 10 to 60 and 118 mg L(-1) with increasing p-NP concentrations from 40 to 85 and 125 mg L(-1).     

Tolerance,Adaptation, and Cell Response Elicited by Micromonospora sp. Facing Tellurite Toxicity: A Biological and Physical-Chemical Characterization

The intense use of tellurium (Te) in industrial applications, along with the improper disposal of Te-derivatives, is causing their accumulation in the environment, where oxyanion tellurite (TeO₃²⁻) is the most soluble, bioavailable, and toxic Te-species. On the other hand, tellurium is a rare metalloid element whose natural supply will end shortly with possible economic and technological effects. Thus, Te-containing waste represents the source from which Te should be recycled and recovered. Among the explored strategies, the microbial TeO₃²⁻ biotransformation into less toxic Te-species is the most appropriate concerning the circular economy. Actinomycetes are ideal candidates in environmental biotechnology. However, their exploration in TeO₃²⁻ biotransformation is scarce due to limited knowledge regarding oxyanion microbial processing. Here, this gap was filled by investigating the cell tolerance, adaptation, and response to TeO₃²⁻ of a Micromonospora strain isolated from a metal(loid)-rich environment. To this aim, an integrated biological, physical-chemical, and statistical approach combining physiological and biochemical assays with confocal or scanning electron (SEM) microscopy and Fourier-transform infrared spectroscopy in attenuated total reflectance mode (ATR-FTIR) was designed. Micromonospora cells exposed to TeO₃²⁻ under different physiological states revealed a series of striking cell responses, such as cell morphology changes, extracellular polymeric substance production, cell membrane damages and modifications, oxidative stress burst, protein aggregation and phosphorylation, and superoxide dismutase induction. These results highlight this Micromonospora strain as an asset for biotechnological purposes.     

Differential susceptibility to HIV-GP120-sensitized apoptosis in CD4+ T-cell clones with different T-helper phenotypes: role of CD95/CD95L interactions

The susceptibility of Th1 and Th2 cell clones to apoptosis following HIV-gp120/CD4 cross-linking and TCR activation was investigated. We show that only Th1 clones are susceptible to HIV-gp120-sensitized apoptosis, although both types of clones express similar levels of CD4 and bind similar amounts of recombinant gp120. Both types of clones, however, undergo apoptosis induced by CD95 cross-linking with agonistic monoclonal antibody (MoAb). Apoptosis induced by gp120 in the Th1 clones is inhibited by either an anti-CD95 neutralizing MoAb or an anti-CD95L neutralizing MoAb as well as by a specific interleukin-1 beta converting enzyme (ICE) inhibitor. When triggered to apoptosis by gp120, Th1 but not Th2 clones express both cell-associated and soluble CD95L. The CD95L produced by Th1 clones induces cell death, inhibitable by anti-CD95 neutralizing MoAb, of CD95 positive Jurkat cells. These data suggest that, like activation-induced apoptosis, HIV-gp120 sensitized apoptosis in Th1 clones occurs via CD95/CD95L interaction and that lack or insufficient production of CD95L is responsible, at least in part, for the resistance of Th2 clones to such apoptosis.     

Advanced laboratory techniques for diagnosing Toxoplasma gondii encephalitis in AIDS patients: significance of intrathecal production and comparison with PCR and ECL-western blotting

The aim of this study was to determine the influence of neonatal focal cerebral hypoxia-ischemia (HI) on sleep-waking pattern, electrocorticogram (ECoG) power spectra and locomotor activity (LA) in adult Wistar rats. Seven-day old pups were subjected to permanent unilateral ligation of the common carotid artery and transient hypoxia (8% O2). At 10 weeks of age, the extent of brain damages was evaluated by magnetic resonance imaging (MRI) and homogenous injured animals were selected before chronic implantation of radiotelemetry device. Using a single ECoG recording channel method, waking (W), paradoxical sleep (PS) and slow wave sleep (SWS) were continuously recorded for 72 h and they were semi-automatically analyzed off-line. We observed that neonatal HI triggers a cascade of events leading, in adult rats, to brain dysfunction characterized by an increase in SWS (55.0 vs. 40.2% in sham-operated rats, p<0.05) and a marked decrease in W phases duration (43.4 vs. 51.5%, p<0.05) while PS was almost suppressed in HI rats (1.6 vs. 8.3%, p<0.05). In addition, power spectral analysis of ECoG revealed significant (p<0.05) alteration in PS power density with a shift of the dominant frequency peak (5.0 to 7.5 Hz for HI and sham-operated rats, respectively). During the light period, we found that HI induced a pronounced reduction of LA (-30%, p<0.05). These results indicate that Wistar rats exposed to a neonatal unilateral cerebral HI present significant ECoG activity, sleep-waking pattern and behavioral disturbances when adults. However, it remains to establish whether such alterations can be prevented by neuroprotective agents.     

CEREBRAL BLOOD FLOW AND METABOLISM EVALUATION IN COMATOSE PATIENTS BY DYNAMIC SPECT

Thirty patients in coma state underwent dynamic SPECT with 133Xe, a validated technique for the quantitation of CBF by SPECT, using a new brain dedicated tomograph: CERTO-96. CMRO2 was computed by multiplying the mean CBF by AVDO2 according to the Fick's principle. The mean values of CBF, AVDO2 and CMRO2 in patients with good outcome were significantly different from those with worse outcome. On the basis of the best "discriminant threshold", CBF and AVDO2 demonstrated an intermediate accuracy in separating the two groups, while CMRO2 showed a satisfactory accuracy.     

Development of Potent Inhibitors of the Mycobacterium tuberculosis Virulence Factor Zmp1 and Evaluation of Their Effect on Mycobacterial Survival inside Macrophages

The enzyme Zmp1 is a zinc‐containing peptidase that plays a critical role in the pathogenicity of Mycobacterium tuberculosis. Herein we describe the identification of a small set of Zmp1 inhibitors based on a novel 8‐hydroxyquinoline‐2‐hydroxamate scaffold. Among the synthesized compounds, N‐(benzyloxy)‐8‐hydroxyquinoline‐2‐carboxamide ( 1 c ) was found to be the most potent Zmp1 inhibitor known to date, and its binding mode was analyzed both by kinetics studies and molecular modeling, identifying critical interactions of 1 c with the zinc ion and residues in the active site. The effect of 1 c on intracellular Mycobacterium survival was assayed in J774 murine macrophages infected with M. tuberculosis H37Rv or M. bovis BCG and human monocyte‐derived macrophages infected with M. tuberculosis H37Rv. Cytotoxicity and genotoxicity were also assessed. Overall, inhibitor 1 c displays interesting in vitro antitubercular properties worthy of further investigation.     

Electrochemical behavior of a new <Emphasis Type="Italic">s</Emphasis>-triazine-based dendrimer

The electrochemical behavior of a new G-2-s-triazine-based dendrimer, 2,4,6-tris-{4-{4,6-bis-{4-{4,6-bis-[(1S,2S)-1,3-dihydroxy-1-(4-nitrophenyl)-prop-2-ylamino]-s-triazin-2-yl}-piperazin-1-yl}-s-triazin-2-yl}-piperazin-1-yl}-s-triazine, (I), was studied in dimethylsulfoxide solution by cyclic voltammetry, on platinum and graphite electrodes. The electrochemical properties of I were compared with that of one of its precursor, N-{4,6-bis{4-{4,6-bis[(1S,2S)-1,3-dihydroxy-1-(4-nitrophenyl)-prop-2-ylamino]-s-triazin-2-yl}-piperazin-1-yl}-triazin-2-yl}-piperazine), (II), together with that of the starting material, (1S,2S)-2-amino-1-(4-nitrophenyl)-propane-1,3-diol (“p-nitrophenylserinol”), (III).