Metastatic pericardial tumors in a dog with equivocal pericardial cytological findings

A metastatic tumor associated with pericardial effusion was diagnosed in a 6-year-old, female, mixed-breed dog. Echocardiography identified multiple echogenic masses adherent to both visceral and parietal pericardium, while results of pericardial fluid cytology were non-diagnostic. The distribution pattern of the masses is remarkable in that they protruded from both pericardial surfaces, rather than one, and demonstrated an oscillatory motion during the cardiac cycle. Pathological examination confirmed the diagnosis of multiple metastatic tumors of the pericardium, with the primary tumor being an anaplastic gastric adenocarcinoma.     

Development of a potentiometric method to measure the resistance to oxidation of white wines and the antioxidant power of their constituents

This work describes a new potentiometric method to evaluate the resistance to oxidation of white wines. Reduction and oxidation titrations were made, and coefficient of variation obtained were 10.87 and 2.65%, respectively. The antioxidant powers of ascorbic acid (Aas) and sulfur dioxide (SO(2)) were evaluated by this method, SO(2) proving to be much less active in this respect than ascorbic acid. The two agents did not demonstrate any antioxidant synergy. A relationship between oxygen present and ascorbic acid was found by the proposed method (1 mmol of O(2) <--> 0.84 mmol of Aas). This method enables the distinction of different wines on the basis of their resistance to oxidation.     

Marine Cyclic Peptides: Antimicrobial Activity and Synthetic Strategies

Oceans are a rich source of structurally unique bioactive compounds from the perspective of potential therapeutic agents. Marine peptides are a particularly interesting group of secondary metabolites because of their chemistry and wide range of biological activities. Among them, cyclic peptides exhibit a broad spectrum of antimicrobial activities, including against bacteria, protozoa, fungi, and viruses. Moreover, there are several examples of marine cyclic peptides revealing interesting antimicrobial activities against numerous drug-resistant bacteria and fungi, making these compounds a very promising resource in the search for novel antimicrobial agents to revert multidrug-resistance. This review summarizes 174 marine cyclic peptides with antibacterial, antifungal, antiparasitic, or antiviral properties. These natural products were categorized according to their sources—sponges, mollusks, crustaceans, crabs, marine bacteria, and fungi—and chemical structure—cyclic peptides and depsipeptides. The antimicrobial activities, including against drug-resistant microorganisms, unusual structural characteristics, and hits more advanced in (pre)clinical studies, are highlighted. Nocathiacins I–III (91–93), unnarmicins A (114) and C (115), sclerotides A (160) and B (161), and plitidepsin (174) can be highlighted considering not only their high antimicrobial potency in vitro, but also for their promising in vivo results. Marine cyclic peptides are also interesting models for molecular modifications and/or total synthesis to obtain more potent compounds, with improved properties and in higher quantity. Solid-phase Fmoc- and Boc-protection chemistry is the major synthetic strategy to obtain marine cyclic peptides with antimicrobial properties, and key examples are presented guiding microbiologist and medicinal chemists to the discovery of new antimicrobial drug candidates from marine sources.     

ToF-SIMS characterization of thermal modifications of bixin from Bixa orellana fruit

Bixa orellana fruit extracts were studied by time-of-flight secondary ion mass spectrometry (ToF-SIMS). The intensity of the peak at m/z 396, assigned to the bixin molecular ion plus two hydrogen atoms (C25H(32)O(4+), decreased as the extract was heated and nearly disappeared with heating above 150 degrees C. Simultaneously, the formation of dimers at m/z 790, 804, and 818 was observed. The ToF-SIMS spectrum is characterized by a large amount of peaks generated by the principal ions and their multiple fragmentation patterns. To extract maximum information from the data set, multivariate statistical analysis was applied. Principal component analysis revealed important structural changes of the bixin molecule upon heating at different temperatures. This information can be used by the food industry as by controlling the temperature of the heating process the red/yellow balance of this colorant can be tuned.     

Nitric oxide impacts bovine sperm capacitation in a cGMP‐dependent and cGMP‐independent manner

We aimed to elucidate whether NO acts in in vitro sperm capacitation in bovine via cGMP/PKG1 pathway. For this, cryopreserved bovine sperm were capacitated in vitro with 20 µg/ml heparin (Control) plus treatments: 1 mM L‐arginine (L‐arg, NO precursor), 50 µM Rp‐8‐Bromo‐β‐phenyl‐1,N²‐ethenoguanosine‐3′,5′‐cyclic monophosphorothioate (Rp‐8‐Br‐cGMPS, selective inhibitor of the binding site for cGMP in PKG1), 1 mM 2‐Phenyl‐4,4,5,5‐tetramethylimidazoline‐1‐oxyl 3‐oxide (PTIO, NO scavenger), and the combinations of L‐arg + RP‐8‐Br‐cGMPS and L‐arg + PTIO. Sperm motility and vigour were determined by phase‐contrast microscopy, capacitation status by chlortetracycline staining, and the intracellular concentration of cGMP was measured by ELISA. Data were subjected to analysis of variance and means compared with SNK test at 5% probability. Motility and vigour were lower in sperm treated with PTIO when compared to Control and other treatments (p < .05). The L‐arg treatment showed the highest percentage of capacitated sperm when compared to the Control and other treatments (Rp‐8‐Br‐cGMPS, L‐arg + Rp‐8‐Br‐cGMPS and PTIO) (69.8 ± 3.4%, 51.2 ± 3.0, 51.1 ± 2.1, 51.2 ± 3.0 and 45.5 ± 2.7, respectively) (p < .05). The capacitation ratio (%) was lower in treatments with Rp‐8‐Br‐cGMPS, L‐arg + Rp‐8‐Br‐cGMPS and PTIO, respectively (p < .05). Lastly, cGMP concentration (pmol/ml) was lower in PTIO and L‐arg + PTIO (1.3 ± 0.3 and 1.6 ± 0.4) and was higher in Rp‐8‐Br‐cGMPS and L‐arg + Rp‐8‐Br‐cGMPS (3.7 ± 0.4 and 4.0 ± 0.5) treatments. We showed that during in vitro capacitation of cattle: (a) NO influences sperm motility and vigour; (b) NO is associated with cGMP synthesis through two independent pathways and (c) the cGMP/PKG1 pathway has a partial role in sperm capacitation and does not involve the L‐arg/NO.     

Pathogenesis of reproductive failure induced by Trypanosoma vivax in experimentally infected pregnant ewes

The present study was aimed at investigating the effect of experimental infection by Trypanosoma vivax in different stages of pregnancy, determining the pathogenesis of reproductive failure, and confirming transplacental transmission. We used 12 pregnant ewes distributed into four experimental groups: G1, was formed by three ewes infected with T. vivax in the first third of pregnancy (30 days); G2 comprised three infected ewes in the final third of pregnancy (100 days); G3 and G4 were composed of three non-infected ewes with the same gestational period, respectively. Each ewe of G1 and G2 was inoculated with 1.25 × 10⁵ tripomastigotes. Clinical examination, determination of parasitemia, serum biochemistry (albumin, total protein, glucose, cholesterol, and urea), packed cell volume (PCV), serum progesterone, and pathological examination were performed. Placenta, amniotic fluid, blood and tissues from the fetuses and stillbirths were submitted to PCR. Two ewes of G1 (Ewe 1 and 3) presented severe infection and died in the 34^th and 35^th days post-infection (dpi), respectively; but both fetuses were recovered during necropsy. In G2, Ewe 5 aborted two fetuses on the 130^th day (30 dpi) of pregnancy; and Ewe 6 aborted one fetus in the 140^th day (40 dpi) of gestation. Ewes 2 and 4 delivered two weak lambs that died five days after birth. Factors possibly involved with the reproductive failure included high parasitemia, fever, low PCV, body score, serum glucose, total protein, cholesterol, and progesterone. Hepatitis, pericarditis, and encephalitis were observed in the aborted fetuses. The presence of T. vivax DNA in the placenta, amniotic fluid, blood, and tissues from the fetuses confirms the transplacental transmission of the parasite. Histological lesion in the fetuses and placenta also suggest the involvement of the parasite in the etiopathogenesis of reproductive failure in ewes.     

Phylogenetic characterization of rabies virus isolates from Carnivora in Brazil

The incidence of canine rabies has been widely reported in Brazil, and new rabies virus (RV) variants, genetically similar to canine RV, have recently been isolated from foxes. In order to derive the epidemiological characteristics of Brazilian Carnivora RV, Brazilian RVs isolated from dogs, cats, and foxes were genetically analyzed. Brazilian Carnivora RV isolates were divided into 2 main lineages. The predominant lineage was found in dogs and cats, which included the Argentinean and Bolivian Carnivora RV isolates, and was extensively distributed throughout Brazil and surrounding countries. The other lineage consisted of three sublineages containing Brazilian dog and fox RV isolates, with the dog sublineages located on an internal branch of 2 fox sublineages, suggesting that RV transmission events might have occurred between foxes and dogs in the past. These results suggest that contact between dogs and wildlife has the potential to generate new rabies variants and that it is important to control RV infection cycles in both dogs and wildlife to prevent spread of rabies infection.