Seasonal effect on Brazilian propolis antibacterial activity

The behavior of microorganisms towards the antibiotic action of propolis has been widely investigated. Since reports dealing with seasonal effect on propolis activity are not available, this assay was carried out aiming to observe the in vitro antimicrobial activity of propolis, collected during the four seasons, on bacterial strains isolated from human infections. Dilution of ethanolic extract of propolis (EEP) in agar was the method performed, with serial concentrations ranging from 0.4 to 14.0% (% v/v). The behavior of some bacteria was analysed according to the incubation period in medium plus propolis, and the survival curve was plotted. It was verified that the growth of Gram-positive bacteria is inhibited by low propolis concentrations (0.4%) whereas Gram-negative bacteria were less susceptible to this substance, the minimal inhibitory concentration ranging from 4.5 to 8.0%. There was no significant difference with regards to the seasonal effect on the survival curve of Staphylococcus aureus and Escherichia coli; after incubation with propolis, there was an efficient antimicrobial action, mainly towards Gram-positive bacteria.

C-reactive protein as a marker of infection in critically ill patients

A prospective, observational study was conducted in a medico-surgical intensive care unit to assess the value of C-reactive protein (CRP), temperature and white cell count (WCC) measurements for the diagnosis of infection in critically ill patients. CRP, temperature and WCC were monitored daily in 76 infected and 36 non-infected patients. Multiple receiver-operating characteristics (ROC) curves were used to compare each parameter for infection diagnosis. The area under the curve (AUC) of CRP was significantly higher than that of temperature (0.93 and 0.75, respectively; p < 0.001). A CRP concentration of >8.7 mg/dL and a temperature of >38.2 degrees C were associated with infection, with a sensitivity of 93.4% and 54.8%, and a specificity of 86.1% and 88.9%, respectively. The ROC curve of WCC showed a poor diagnostic performance. The combination of CRP and temperature increased the specificity for infection diagnosis to 100%. In the subgroup of patients with ventilator-associated pneumonia (n = 48), CRP measurements were more reliable than temperature (AUC 0.92 and 0.78, respectively; p 0.006). The CRP levels in infected patients with sepsis, severe sepsis and septic shock were 15.2 +/- 8.2, 20.3 +/- 10.9 and 23.3 +/- 8.7 mg/dL, respectively (p 0.044). It was concluded that CRP was a better marker of infection than temperature. However, the combination of CRP and temperature measurements further increased the specificity for infection diagnosis, even in the subgroup of patients with VAP.

C-reactive protein as an indicator of sepsis

OBJECTIVE

To determine the use of plasma C-reactive protein (CRP) concentrations, body temperature (BT) and white blood cell count (WBC) in the detection of sepsis in critically ill patients.

DESIGN

All patients admitted for more than 24 h in the intensive care unit (ICU) were prospectively included. Patients were followed up to ICU discharge and each patient-day was classified in one of four categories according to the infectious status: 1) Negative, patient-day without systemic inflammatory response syndrome (SIRS); 2) Definite, patient-day with SIRS and a positive culture; 3) SIRS, patient-day with SIRS and negative or no cultures. The last group was subdivided according to the following criteria: a) new, or persistence of, pulmonary infiltrates, b) the presence of pus in a place known to be sterile. Patient-days without these criteria were classified as SIRS with improbable sepsis (Unlikely), and with one criteria or more as SIRS with probable sepsis (Probable).

SETTING

Medical/surgical intensive care unit.

PATIENTS

Twenty-three patients were followed.

MEASUREMENTS AND RESULTS

A total of 306 patient-days were analysed: 20 Negative, 15 Definite, 63 Unlikely and 208 Probable. The median (range) CRP values for Negative, Unlikely, Probable and Definite groups were as follows: 24.5 (7-86), 34 (5-107), 143 (39-544), and 148 (52-320) mg/l. The plasma CRP levels were significantly related to the infectious status (Negative, Unlikely, Probable or Definite) of the patient-day classification (p < 0.05). Concentrations of CRP in the Negative and Unlikely groups were significantly lower than in the Probable and Definite ones (p < 0.05). A plasma CRP of 50 mg/l or more was highly suggestive of sepsis (sensitivity 98.5%, specificity 75%).

CONCLUSIONS

Daily measurement of CRP is useful in the detection of sepsis and it is more sensitive than the currently used markers, such as BT and WBC.

The blocking effect of epidural analgesia on the adrenocortical and hyperglycemic responses to surgery

The adrenocortical and hyperglycemic responses to hysterectomy were studied in five groups of patients receiving: general anesthesia (group I), general anesthesia + epidural analgesia extending from Th10-S5 (group II), general anesthesia + epidural analgesia extending from Th8-S4--5 (group III), general anesthesia + epidural analgesia extending from Th4--6-S5 (group IV) and epidural analgesia extending from Th4-S5 without general anesthesia (group V). The results showed that the cortisol response was abolished in group V, inhibited in group IV and normal in groups II and III. The hyperglycemic response to surgery was inhibited in groups II, III and IV, and abolished in group V. Epidural analgesia from Th4 to S5, preventing the adrenocortical and hyperglycemic responses to hysterectomy, and possibly also inhibiting other components of the endocrine-metabolic response to surgery, may have important applications in further studies of the physiologic significance of the endocrine-metabolic response to surgery.

Differentiation of new insulin-producing cells is induced by injury in adult pancreatic islets

The ability of the adult pancreas to generate new insulin (beta) cells has been controversial because of difficulties in unequivocally identifying the precursor population. We recently determined that beta cells were generated during development from precursors that expressed the homeodomain-containing transcription factor pancreas duodenum homeobox gene-1 (PDX-1). To investigate whether PDX-1+ stem cells are present in adult pancreas, we examined two animal models of diabetes. One model was produced by injecting adult mice with streptozotocin (SZ), a toxin that produces hyperglycemia due to rapid and massive beta cell death. After SZ-mediated elimination of existing IN+/PDX-1+ cells, a population of somatostatin (SOM)+/PDX-1+ cells, a cell type thought to represent an embryonic islet precursor cell, appeared in islets. The appearance of SOM+/PDX-1+ cells was followed in time by the differentiation to SOM+/IN+/PDX-1+ cells. SOM+/PDX-1+ cells also appeared in islets of nonobese diabetic mice, a strain of mice in which beta cell destruction is immune-mediated. Our findings establish the existence of PDX-1+ beta cell precursors in the adult pancreas and indicate that their differentiation is induced by islet injury.

Reactivity of human salivary proteins families toward food polyphenols

Tannins are well-known food polyphenols that interact with proteins, namely, salivary proteins. This interaction is an important factor in relation to their bioavailability and is considered the basis of several important properties of tannins, namely, the development of astringency. It has been generally accepted that astringency is due to the tannin-induced complexation and/or precipitation of salivary proline-rich proteins (PRPs) in the oral cavity. However, this complexation is thought to provide protection against dietary tannins. Neverthless, there is no concrete evidence and agreement about which PRP families (acidic, basic, and glycosylated) are responsible for the interaction with condensed tannins. In the present work, human saliva was isolated, and the proteins existing in saliva were characterized by chromatographic and proteomic approaches (HPLC-DAD, ESI-MS, sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE), and MALDI-TOF). These approaches were also adapted to study the affinity of the different families of salivary proteins to condensed tannins by the interaction of saliva with grape seed procyanidins. The results obtained when all the main families of salivary proteins are present in a competitive assay, like in the oral cavity, demonstrate that condensed tannins interact first with acidic PRPs and statherin and thereafter with histatins, glycosylated PRPs, and bPRPs.

Dopamine synthesis and metabolism in rhesus monkey retina: development, aging, and the effects of monocular visual deprivation

The normal postnatal development, the influence of age, and the effects of visual deprivation on the dopamine system in the retina of rhesus monkeys were examined. The lowest level of retinal dopamine was found at birth. By 3-4 weeks of age, the dopamine concentration had more than doubled. This level remained relatively constant in the retinas of older infants and of adult monkeys up to 34 yr of age. The level of the dopamine metabolite 3,4-dihydroxyphenylacetic acid (DOPAC) and the activity of tyrosine hydroxylase did not significantly change as a function of age during the postnatal life span. Monocular occlusion of newborn or infant monkeys for 1-15 months with opaque contact lenses resulted in decreases in the retinal concentrations of dopamine and DOPAC relative to the concentrations in the same animals' unoccluded eyes. Occlusion also resulted in a lower level of tyrosine hydroxylase activity in the retina. Monocular eyelid suture from birth to 15 months of age resulted in less consistent alterations of retinal dopamine and DOPAC levels; tyrosine hydroxylase activity, however, was consistently reduced by lid suture. Thus, dopamine synthesis and metabolism, and the ontogenetic increase of the retinal dopamine level of rhesus monkey are reduced by light deprivation.

C-reactive protein as a marker of ventilator-associated pneumonia resolution: a pilot study

The aim of this study was to evaluate C-reactive protein (CRP) levels, body temperature and white cell count (WCC) after prescription of antibiotics in order to describe the clinical resolution of ventilator-associated pneumonia (VAP). A cohort of 47 VAP patients with microbiological confirmation of disease was assessed. CRP levels, body temperature and WCC were monitored daily. On day 4 of the antibiotic therapy, the CRP level of survivors was 0.62 times the initial value, whereas, in nonsurvivors, it was 0.98. Body temperature and WCC remained almost unchanged. By day 4, a CRP of >0.6 times the initial level was a marker of poor outcome (sensitivity 0.92; specificity 0.59). Patients were divided according to their CRP patterns of response to antibiotics: fast response, slow response, nonresponse, and biphasic response. All patients with fast and slow response patterns survived, whereas those showing nonresponse and a biphasic response pattern exhibited a mortality of 78 and 75%, respectively. The adequacy of the initial antibiotic therapy had a marked influence on the rate of CRP decrease, as well as on mortality. In conclusion, daily C-reactive protein measurements after antibiotic prescription were useful in the identification, as early as day 4, of ventilator-associated pneumonia patients with poor outcome. The identification of the pattern of C-reactive protein response to antibiotics was useful in the recognition of individual clinical course, improving or worsening, as well as of the rate of improvement.

Understanding the molecular mechanism of anthocyanin binding to pectin

Association between anthocyanins and carbohydrates has drawn attention over the past few years and this interaction is of particularly importance in food chemistry since these compounds are often found together in plants and foodstuffs. This work intended to bring insights on the interaction between ionic carbohydrates (pectin) and two anthocyanins (cyanidin-3-O-glucoside, cy3glc and delphinidin-3-O-glucoside, dp3glc). The interaction between the flavylium cation and hemiketal anthocyanin forms was characterized by saturation transfer difference (STD) NMR spectroscopy and the respective dissociation constant (Kd) was obtained. This binding was also studied by Molecular Dynamics simulation. In the presence of the anthocyanin hemiketal form a weak interaction between anthocyanins and pectin seems to occur. A variation in the extent of this interaction was also noticed for the two anthocyanins with dp3glc bearing three hydroxyl groups, revealing to be a stronger binder to pectin (Kd ≈ 180 μM for dp3glc and Kd ≈ 250 μM for cy3glc). Experiments performed at acidic pH (flavylium cation) revealed a much stronger interaction (Kd ≈ 2 μM). These experimental results were also supported by theoretical studies which also revealed a stronger interaction in the presence of the anthocyanin flavylium cation and also a stronger interaction between pectin and dp3glc than with cy3glc (for the hemiketal form).

ErbB-2 kinase is required for constitutive stat 3 activation in malignant human lung epithelial cells

Overexpression of the growth factor receptor ErbB-2/Her2/Neu has been implicated in the development of non-small-cell lung cancer. We have reported that the transformation of human lung epithelial cells by c-erbB-2 also requires an active ErbB-1 (EGF receptor) and the autocrine production of its ligand, TGF-alpha. In this report, we demonstrate that STAT 3 is constitutively activated in these cells by the TGF-alpha-stimulated ErbB-1/-2 heterodimer complex. STAT 3 activation was confirmed by mobility shift assays and nuclear localization. ErbB-1 was required, but not sufficient for the TGF-alpha-induced activation of STATs. Inhibition of ErbB-2 kinase activity by tyrphostin AG825 prevented the constitutive activation of STAT 3 in the TGF-alpha-producing, ErbB-1 expressing cell line. Our results demonstrate a requirement for ErbB-2 kinase activity to establish constitutive STAT 3 activation resulting from an autocrine ErbB-1/ TGF-alpha loop. Int. J. Cancer 83:564-570, 1999. Published 1999 Wiley-Liss, Inc.

An International Multispecialty Validation Study of the IgG4-Related Disease Responder Index

OBJECTIVE

IgG4-related disease (IgG4-RD) can cause fibroinflammatory lesions in nearly any organ, leading to organ dysfunction and failure. The IgG4-RD Responder Index (RI) was developed to help investigators assess the efficacy of treatment in a structured manner. The aim of this study was to validate the RI in a multinational investigation.

METHODS

The RI guides investigators through assessments of disease activity and damage in 25 domains, incorporating higher weights for disease manifestations that require urgent treatment or that worsen despite treatment. After a training exercise, investigators reviewed 12 written IgG4-RD vignettes based on real patients. Investigators calculated both an RI score as well as a physician's global assessment (PhGA) score for each vignette. In a longitudinal assessment, 3 investigators used the RI in 15 patients with newly active disease who were followed up over serial visits after treatment. We assessed interrater and intrarater reliability, precision, validity, and responsiveness.

RESULTS

The 26 physician investigators included representatives from 6 specialties and 9 countries. The interrater and intrarater reliability of the RI was strong (0.89 and 0.69, respectively). Correlations (construct validity) between the RI and PhGA were high (Spearman's r = 0.9, P < 0.0001). The RI was sensitive to change (discriminant validity). Following treatment, there was significant improvement in the RI score (mean change 10.5 [95% confidence interval (95% CI) 5.4-12], P < 0.001), which correlated with the change in the PhGA. Urgent disease and damage were captured effectively.

DISCUSSION

In this international, multispecialty study, we observed that the RI is a valid and reliable disease activity assessment tool that can be used to measure response to therapy.

Quaternary structure of the insulin-insulin receptor complex

The three-dimensional (3D) structure of the intrinsically dimeric insulin receptor bound to its ligand, insulin, was determined by electron cryomicroscopy. Gold-labeled insulin served to locate the insulin-binding domain. The 3D structure was then fitted with available known high-resolution domain substructures to obtain a detailed contiguous model for this heterotetrameric transmembrane receptor. The 3D reconstruction indicates that the two alpha subunits jointly participate in insulin binding and that the kinase domains in the two beta subunits are in a juxtaposition that permits autophosphorylation of tyrosine residues in the first step of insulin receptor activation.

Middle cerebral artery blood velocity during exercise with beta-1 adrenergic and unilateral stellate ganglion blockade in humans

A reduced ability to increase cardiac output (CO) during exercise limits blood flow by vasoconstriction even in active skeletal muscle. Such a flow limitation may also take place in the brain as an increase in the transcranial Doppler determined middle cerebral artery blood velocity (MCA V(mean)) is attenuated during cycling with beta-1 adrenergic blockade and in patients with heart insufficiency. We studied whether sympathetic blockade at the level of the neck (0.1% lidocaine; 8 mL; n=8) affects the attenuated exercise - MCA V(mean following cardio-selective beta-1 adrenergic blockade (0.15 mg kg(-1) metoprolol i.v.) during cycling. Cardiac output determined by indocyanine green dye dilution, heart rate (HR), mean arterial pressure (MAP) and MCA V(mean) were obtained during moderate intensity cycling before and after pharmacological intervention. During control cycling the right and left MCA V(mean) increased to the same extent (11.4 +/- 1.9 vs. 11.1 +/- 1.9 cm s(-1)). With the pharmacological intervention the exercise CO (10 +/- 1 vs. 12 +/- 1 L min(-1); n=5), HR (115 +/- 4 vs. 134 +/- 4 beats min(-1)) and delta MCA V(mean) (8.7 +/- 2.2 vs. 11.4 +/- 1.9 cm s(-1) were reduced, and MAP was increased (100 +/- 5 vs. 86 +/- 2 mmHg; P < 0.05). However, sympathetic blockade at the level of the neck eliminated the beta-1 blockade induced attenuation in delta MCA V(mean) (10.2 +/- 2.5 cm s(-1)). These results indicate that a reduced ability to increase CO during exercise limits blood flow to a vital organ like the brain and that this flow limitation is likely to be by way of the sympathetic nervous system.

Tissue factor deficiency causes cardiac fibrosis and left ventricular dysfunction

Exposure of blood to tissue factor (TF) activates the extrinsic (TF:FVIIa) and intrinsic (FVIIIa:FIXa) pathways of coagulation. In this study, we found that mice expressing low levels of human TF ( approximately 1% of wild-type levels) in an mTF(-/-) background had significantly shorter lifespans than wild-type mice, in part, because of spontaneous fatal hemorrhages. All low-TF mice exhibited a selective heart defect that consisted of hemosiderin deposition and fibrosis. Direct intracardiac measurement demonstrated a 30% reduction (P < 0.001) in left ventricular function in 8-month-old low-TF mice compared with age-matched wild-type mice. Mice expressing low levels of murine FVII ( approximately 1% of wild-type levels) exhibited a similar pattern of hemosiderin deposition and fibrosis in their hearts. In contrast, FIX(-/-) mice, a model of hemophilia B, had normal hearts. Cardiac fibrosis in low-TF and low-FVII mice appears to be caused by hemorrhage from cardiac vessels due to impaired hemostasis. We propose that TF expression by cardiac myocytes provides a secondary hemostatic barrier to protect the heart from hemorrhage.

Fidelity of translesional synthesis past benzo[a]pyrene diol epoxide-2'-deoxyguanosine DNA adducts: marked effects of host cell, sequence context, and chirality

We have used a site-specific approach to investigate the mutagenic potential of (+)- and (-)-trans-anti-benzo[a]pyrene diol epoxide (BPDE) DNA adducts. Oligodeoxyribonucleotides (5'TCCTCCTG1G2-CCTCTC), modified at the exocyclic amino groups of G1 or G2, were incorporated into a single-stranded shuttle vector and introduced into Escherichia coli or simian kidney (COS) cells. This experimental system permits translesional synthesis to proceed in the absence of DNA repair. The presence of (+)- or (-)-BPDE-N2-dG adducts strongly inhibited translesional synthesis in E. coli; induction of cellular SOS functions reduced this blocking effect. Vectors containing (+)-BPDE adducts at G1 or G2 generated mutation frequencies of 19% and 3%, respectively; these values were not altered significantly by induction of SOS functions. In COS cells, (+)-BPDE-modified vectors generated mutation frequencies of 13% at G1 and 45% at G2. In E. coli, the (-)-BPDE adduct generated mutation frequencies of < or = 2% at G1 and G2 and, in COS cells, 13% at G1 and 21% at G2. The predominant mutations in E. coli and COS cells were G-->T transversions targeted to the site of the lesion; however, when G2 was modified, a significant number of targeted G-->A and G-->C mutations were observed in COS cells. We conclude from this study that (+)-and (-)-BPDE-N2-dG adducts pair preferentially to dCMP and dAMP during translesional synthesis in a process that is strongly influenced by the stereochemistry of the adduct, by the bases flanking the lesion, and by host cell factors.

Mutagenic potential of stereoisomeric bay region (+)- and (-)-cis-anti-benzo[a]pyrene diol epoxide-N2-2'-deoxyguanosine adducts in Escherichia coli and simian kidney cells

We have investigated the mutagenic potential of site-specifically positioned DNA adducts with (+)- and (-)-cis-anti stereochemistry derived from the binding of r7,t8-dihydroxy-t9,10-epoxy-7,8,9, 10-tetrahydrobenzo[a]pyrene (BPDE) to N2-2'-deoxyguanosine (G1 or G2) in the sequence context 5'TCCTCCTG1 G2CCTCTC. BPDE-modified oligodeoxynucleotides were ligated to a single-stranded DNA vector and replicated in Escherichia coli or simian kidney (COS7) cells. The presence of (+)- or (-)-cis adduct strongly reduced the yield of transformants in E. coli, and the yield was improved by the induction of SOS functions. Both adducts were mutagenic in E. coli and COS cells, generating primarily G --> T transversions. In E. coli, the (-)-cis adduct was more mutagenic than the (+)-cis adduct, while in COS cells, both adducts were equally mutagenic. These results were compared with those obtained with stereoisomeric (+)- and (-)-trans adducts [Moriya, M., et al. (1996) Biochemistry 35, 16646-16651). In E. coli, cis adducts, especially (-)-cis adducts, are consistently more mutagenic than the comparable trans adduct. In COS cells, trans adducts yield higher frequencies of mutations than the two cis adducts and, with the exception of the high-mutation frequency associated with the (+)-trans adduct at G2, relatively small differences in mutation frequencies are observed for the three other adducts. In E. coli, mutation frequency is a pronounced function of adduct stereochemistry and adduct position. These findings suggest that the fidelity of translesional synthesis across BPDE-dG adducts is strongly influenced by adduct stereochemistry, nucleotide sequence context, and the DNA replication complex.

Effect of changes in PCO2 and body positions on intraocular pressure during general anaesthesia

Elevated arterial carbon dioxide tension, induced by the administration of CO2 via the respiratory air or by hypoventilation, entailed a gradual increase in the IOP in patients without eye diseases under general anaesthesia. A sudden cessation of CO2 administration or hyperventilation caused such a rapid, simultaneous fall in IOP to values below the initial level that the pressure variations must be of vascular nature, presumably related to changes in choroidal blood volume. The above-mentioned procedures always cause a change in the central venous pressure (CVP) simultaneously with the IOP changes. Alterations of the CVP induced by hydrostatic factors in postural changes, placing the head 15 degrees above or below the horizontal level while keeping the PaCO2 constant, caused IOP changes of the same configuration and magnitude as described above. It is concluded, therefore, that presumably the CO2-conditioned IOP changes are due predominantly to changes in central venous pressure, being one link in a CO2-conditioned action upon the general circulation, entailing passive secondary changes in the choroidal venous blood volume and thereby an influence upon the IOP. On the basis of the present results it appears rational to recommend hyperventilation to keep the PaCO2 between 25 and 30 mm and a 15 degree anti-Trendelenburg position in operations on the eye under general anaesthesia, since both procedures afford a low central venous pressure and consequently a low pressure in the posterior segment of the eye, with its attendant advantages as regards vitreous complications and the insertion of intraocular lenses. Owing to the risk of an unacceptable fall in BP in the combined procedure, a frequent checking of the BP is needed.

A systematic review of natural products for skin applications: Targeting inflammation, wound healing, and photo-aging

BACKGROUND

Every day the skin is constantly exposed to several harmful factors that induce oxidative stress. When the cells are incapable to maintain the balance between antioxidant defenses and reactive oxygen species, the skin no longer can keep its integrity and homeostasis. Chronic inflammation, premature skin aging, tissue damage, and immunosuppression are possible consequences induced by sustained exposure to environmental and endogenous reactive oxygen species. Skin immune and non-immune cells together with the microbiome are essential to efficiently trigger skin immune responses to stress. For this reason, an ever-increasing demand for novel molecules capable of modulating immune functions in the skin has risen the level of their development, particularly in the field of natural product-derived molecules.

PURPOSE

In this review, we explore different classes of molecules that showed evidence in modulate skin immune responses, as well as their target receptors and signaling pathways. Moreover, we describe the role of polyphenols, polysaccharides, fatty acids, peptides, and probiotics as possible treatments for skin conditions, including wound healing, infection, inflammation, allergies, and premature skin aging.

METHODS

Literature was searched, analyzed, and collected using databases, including PubMed, Science Direct, and Google Scholar. The search terms used included "Skin", "wound healing", "natural products", "skin microbiome", "immunomodulation", "anti-inflammatory", "antioxidant", "infection", "UV radiation", "polyphenols", "polysaccharides", "fatty acids", "plant oils", "peptides", "antimicrobial peptides", "probiotics", "atopic dermatitis", "psoriasis", "auto-immunity", "dry skin", "aging", etc., and several combinations of these keywords.

RESULTS

Natural products offer different solutions as possible treatments for several skin conditions. Significant antioxidant and anti-inflammatory activities were reported, followed by the ability to modulate immune functions in the skin. Several membrane-bound immune receptors in the skin recognize diverse types of natural-derived molecules, promoting different immune responses that can improve skin conditions.

CONCLUSION

Despite the increasing progress in drug discovery, several limiting factors need future clarification. Understanding the safety, biological activities, and precise mechanisms of action is a priority as well as the characterization of the active compounds responsible for that. This review provides directions for future studies in the development of new molecules with important pharmaceutical and cosmeceutical value.

Electrochemical oxidation of humic acid and sanitary landfill leachate: Influence of anode material, chloride concentration and current density

The influence of applied current density and chloride ion concentration on the ability of Ti/Pt/PbO2 and Ti/Pt/SnO2-Sb2O4 anodes for the electrochemical oxidation of humic acid and sanitary landfill leachate samples was assessed and compared with that of BDD anode. For the experimental conditions used, results show that both organic load and nitrogen removal rates increase with the applied current density and chloride ion concentration, although there is an optimum COD/[Cl-]0 ratio below which there is no further increase in COD removal. Metal oxide anodes present a similar performance to that of BDD, being the results obtained for Ti/Pt/PbO2 slightly better than for Ti/Pt/SnO2-Sb2O4. Contrary to BDD, Ti/Pt/PbO2 promotes lower nitrate formation and is the most suitable material for total nitrogen elimination. The importance of the optimum ratio of Cl-/COD/NH4 +initial concentrations is discussed.

Cardiovascular and ventilatory responses to dynamic exercise during epidural anaesthesia in man

1. In order to evaluate the importance of afferent neural feedback from the working muscles for cardiovascular and ventilatory responses to dynamic exercise, epidural anaesthesia was induced at L3-L4. Six healthy males cycled for 20 min at 57% of maximum oxygen uptake and for 8-12 min at increasing work intensities until exhaustion at 238 +/- 30 W without as well as with epidural anaesthesia. 2. Presence of afferent neural blockade was verified by cutaneous sensory analgesia below T10-T11 and attenuated post-exercise ischaemic pressor response (45 +/- 8-24 +/- 6 mmHg). Efferent sympathetic nerves appear to be intact since basal heart rate and blood pressure as well as the cardiovascular responses to a Valsalva manoeuvre and to a cold pressor test were unchanged. 3. During dynamic exercise with epidural anaesthesia, blood pressure was lower than in control experiments; however, ventilation and heart rate were not affected. 4. The results indicate that afferent neural activity from the working muscles is important for blood pressure regulation during dynamic exercise in man but may not be necessary for eliciting the ventilatory and heart rate responses.

Protective effects of hydroxytyrosol-supplemented refined olive oil in animal models of acute inflammation and rheumatoid arthritis

Virgin olive oil is the primary source of fat in the Mediterranean diet, and its beneficial health effects have been related with oleic acid and phenolic compounds content. Hydroxytyrosol, a typical virgin olive oil phenolic compound, has beneficial antioxidant and anti-inflammatory properties as previously reported. The aim of this study was to evaluate the effect of hydroxytyrosol-supplemented refined olive oil at 0.5 and 5 mg/kg in a rodent model of rheumatoid arthritis. Rheumatoid arthritis was induced by intradermic administration, in male Wistar rats, of Freund's adjuvant with collagen type II on days 1 and 21. Hydroxytyrosol-supplemented refined olive oils were administrated by gavage from day 23 until day 35. The treatment at 5-mg/kg dose significantly decreased paw edema (P<.01), histological damage, cyclooxygenase-2 and inducible nitric oxide synthase expression, and markedly reduced the degree of bone resorption, soft tissue swelling and osteophyte formation, improving articular function in treated animals. Acute inflammation, induced by carrageenan, was also evaluated for hydroxytyrosol-supplemented refined olive oils at 0.5 and 5 mg/kg. Both doses significantly reduced paw edema (P<.001). Our results suggest that the supplementation of refined olive oil with hydroxytyrosol may be advantageous in rheumatoid arthritis with significant impact not only on chronic inflammation but also on acute inflammatory processes.

Effects of muscarinic cholinergic receptor antagonists on postnatal eye growth of rhesus monkeys

PURPOSE

To study a potential role for muscarinic receptors in the inhibition of deprivation-induced excessive axial elongation and myopia in a monkey model.

METHODS

The right eyes of 20 newborn rhesus monkeys were occluded with a black contact lens. In seven monkeys each, either atropine or pirenzepine was topically applied daily to the occluded eyes. The nonoccluded fellow eyes and both the occluded and nonoccluded fellow eyes of another six monkeys were treated with vehicle solution.

RESULTS

After 33 to 39 weeks, in 5 monkeys of the vehicle group, occluded eyes were longer and the myopic shift significantly greater than in the nonoccluded fellow eyes. In six atropine-treated monkeys, axial length and reduction of the initial hyperopia of occluded and nonoccluded fellow eyes were not different statistically. The myopic shift of the occluded eyes was significantly smaller than in the vehicle-treated occluded eyes. In the pirenzepine-treated group, axial length of the occluded eyes was similar to the nonoccluded eyes of controls and the occluded eyes of atropine-treated monkeys. There was a trend of pirenzepine to reduce the myopic shift of the occluded eye. No effect of atropine or pirenzepine was noted on muscarinic receptor density in retina, brain, or heart, but a small increase was observed in iris + ciliary body.

CONCLUSIONS

The drug treatment results implicate muscarinic receptors in postnatal eye growth regulation. Because of interanimal differences our data do not indicate whether nonselective or selective muscarinic blockade is more effective in reducing deprivation-induced myopia.

Isolation and Characterization of Anthocyanins from Hibiscus sabdariffa Flowers

The intense red-colored Hibiscus sabdariffa flowers are an inexpensive source of anthocyanins with potential to be used as natural, innocuous, and health-beneficial colorants. An anthocyanin-rich extract from hibiscus flowers was obtained by ultrasound-assisted extraction. By a single-step process fractionation using a Sep-Pak C18 cartridge, the main hibiscus anthocyanins, delphinidin-3-O-sambubioside (Dp-samb) and cyanidin-3-O-sambubioside (Cy-samb), were separated and then characterized via NMR and HPLC-ESIMS data. Since Dp-samb was the most abundant anthocyanin identified in the extract, its colorant properties were studied by the pH jumps method, which allowed the calculation of the single acid-base equilibrium (pK'a 2.92), the acidity (pKa 3.70), and the hydration constants (pKh 3.02). Moreover, by using size-exclusion chromatography, new cyanidin-derived anthocyanins (with three or more sugar units) were successfully identified and reported for the first time in the hibiscus extract.

Form deprivation myopia in adolescent monkeys

BACKGROUND

Early in life, at ages corresponding to the rapid infantile phase of ocular growth in humans, visual feedback can modulate refractive development in monkeys and many other species. To determine if vision-dependent mechanisms can still influence refractive development in primates during the slow juvenile phase of ocular growth, the time period when myopia typically develops in human children, we examined the effects of form deprivation on adolescent monkeys.

METHODS

Unilateral, form deprivation was produced in four rhesus monkeys by surgically fusing the eyelids of one eye. The onset of deprivation was between 3.7 and 5 years of age, which corresponds to onset ages between approximately 15 and 20 human years. The ocular effects of form deprivation were assessed by cycloplegic retinoscopy and A-scan ultrasonography.

RESULTS

At the onset of form deprivation all four monkeys were isometropic and the axial dimensions in the two eyes were well matched. After 71 to 80 weeks of form deprivation, all of the deprived eyes had become relatively more myopic than their fellow non-treated eyes (mean anisometropia = -2.03 +/- 0.78 D) and they exhibited relative increases in vitreous chamber depth (mean = 0.55 +/- 0.31 mm) and axial length (mean = 0.49 +/- 0.35 mm).

DISCUSSION

Our results demonstrate that vision-dependent mechanisms can influence ocular growth and refractive development in "teenage" monkeys. These results raise the possibility that visual experience may be involved in the genesis of school-age myopia in children.