First report of Rhytidodes gelatinosus (Rudolphi, 1819) Looss, 1901 (Digenea: Rhytidodidae) in an olive-ridley Turtle Lepidochelys olivacea (Eschscholtz, 1829) from Brazil.

This article reports the first occurrence of Rhytidodes gelatinosus (Rudolphi, 1819) Looss, 1901 (Digenea: Rhytidodidae) in the olive-ridley turtle Lepidochelys olivacea (Testudines: Chelonidae), in an individual found in the State of Sergipe, Brazil. Although R. gelatinosus has already been described in other species of sea turtles in the world, this is the first report of this parasite in L. olivacea. We also present a list of hosts and locations where this helminth has already been identified.

Lesions associated with Halocercus brasiliensis Lins de Almeida, 1933 in the lungs of dolphins stranded in the Northeast of Brazil.

The parasitic fauna of cetaceans is an important tool for ecological studies, including analyses on the causes of death. Halocercus brasiliensis is a nematode frequently found in the bronchi and bronchioles of some cetaceans, and it is commonly associated with focal inflammation of the respiratory tract leading to bacterial pneumonia and septicemia and, sometimes, to death. The objective of this study was to report infections by H. brasiliensis in the respiratory tract of Delphinidae stranded on the northern seaside of Bahia, Sergipe, and south of Alagoas, all states in the northeast region of Brazil. A total of 30 individuals, 1 Feresa attenuate (pygmy killer whale), 9 Stenella clymene (Clymene dolphin), and 20 Sotalia guianensis (Guiana dolphin) were studied. In 16 of them, the presence of H. brasiliensis was observed with a mean intensity of 3.5 ± 0.6 (range 1-9) in the hosts. Macroscopically, parasitic calcified nodules, lung congestion, edema, and emphysema were observed. Histopathological examination showed interstitial and granulomatous pneumonia with multifocal infiltrates, discrete to moderate edema, congestion, diffuse hemorrhage, and foci of calcification. We conclude that parasitic pneumonia in the sampled individuals may have directly contributed to stranding and death of the animals.

A contribution for the definition of serum chemistry values in captive adults Antillean manatees (Trichechus manatus manatus Linnaeus, 1758).

Serum chemistry analyses represents a fundamental tool for the diagnosis and understanding of diseases in marine mammals. Although several studies are being conducted within the field of clinical pathology, haematological and serum chemistry data for Antillean manatees are deficient. The purpose of this study was to determine serum chemistry values for captive Antillean manatees within the CMA/Ibama facility in Brazil. Serum samples were obtained from five captive adult Antillean manatees fed with seagrass and analysed for aspartate aminotransferase, alanine aminotransferase, bilirubin, alkaline phosphatase, urea, creatinine, glucose, triglycerides, cholesterol, total protein, albumin, globulin, phosphate, chloride, calcium and uric acid. Blood chemistry parameters were determined using a semi-automatic analyzer. Maximum, minimum, mean and standard deviations were calculated for each serum chemistry parameter. Differences on the values of males and females were verified using an unpaired Student's t-test. All the parameters analysed were similar between sexes, with exception of AP, which was higher in females (191.43 +/- 31.86 U/l). Alanine aminotransferase and uric acid values for Trichechus manatus manatus are reported for the first time in this paper. This study is the first to report serum chemistry parameter values for long-term captive male and female Antillean manatees. Therefore, the lower values of albumin, phosphate, chloride, cholesterol and triglycerides obtained here highlight the importance of clinical pathology during health monitoring of captive marine mammals.

Effects of the constitutively active proteolytic fragment of protein kinase C on the contractile properties of demembranated smooth muscle fibres.

The role of protein kinase C (PKC) in regulating the contractile state of smooth muscle was investigated using the constitutively active catalytic fragment of PKC (PKM) with skinned (demembranated) chicken gizzard fibres. PKM attenuated a submaximal contraction in gizzard smooth muscle skinned fibres, but not in rabbit cardiac skinned fibres. PKM-mediated relaxation of submaximal contractions of smooth muscle was accompanied by a reduction in the rate of ATP hydrolysis in the fibre and by phosphorylation of the 20 kDa light chain of gizzard myosin at the PKC sites (serine-1, serine-2 and threonine-9). In addition, several other endogenous proteins were phosphorylated by PKM. However, the inhibitory effects on tension and ATPase are consistent with the biochemical effects of PKC-catalysed phosphorylation of myosin, i.e. reduction of the actin-activated MgATPase activity of myosin prephosphorylated at serine-19 by myosin light chain kinase. Pretreatment of skinned fibres with PKM and ATP gamma S in the absence of Ca2+ had no inhibitory effect on the subsequent submaximal Ca(2+)-activation of force. Consistent with this observation, PKC was not able to utilize ATP gamma S as a substrate, confirming that the observed effects were the result of PKM-catalysed protein phosphorylation. We suggest that PKC may have two distinct effects on smooth muscle contraction: translocation of PKC to the sarcolemma on stimulation results in phosphorylation of a protein(s) other than myosin and a slow, sustained contraction; in some circumstances PKC may undergo proteolysis to PKM resulting in myosin phosphorylation at PKC-specific sites, a reduction in ATPase activity and relaxation of the muscle.

Effects of gold coordination complexes on neutrophil function are mediated via inhibition of protein kinase C.

Previous studies have shown that the gold compounds auranofin (AUR) and gold sodium thiomalate (GST) inhibit responses of various cells and tissues. We found that superoxide anion generation induced in human neutrophils by the chemotactic tripeptide fmet-leu-phe (1 microM), fluoride (18 mM), or phorbol myristate acetate (PMA, 100 nM) was inhibited by pretreatment of cells with 5-100 microM AUR. The extent of inhibition was dependent on AUR concentration and duration of the preincubation. GST was much less potent, inasmuch as only weak effects were observed at 5 times higher concentrations. The ineffectiveness of GST was attributed to its slower rate of penetration into cells, compared with AUR. The finding that mobilization of internal Ca2+ stores was not blocked in AUR-treated cells suggests that phospholipase C-mediated hydrolysis of polyphosphoinositides to inositol 1,4,5-trisphosphate was not inhibited by the drug. Because PMA is known to mimic the action of diacylglycerol in activating protein kinase C (PKC), we investigated the possibility that gold compounds might be interfering with signal transduction at this level. Enzymatic assays indicated that both gold compounds reduced the level of PKC activity associated with the cytosol; however, translocation of PKC to the plasma membrane was not found. Immunoblot analyses carried out with polyclonal anti-PKC antisera revealed that the gold compounds did not cause degradation of PKC or increase translocation to the membrane. Further studies indicated that enhanced endogenous protein phosphorylation resulting from PMA stimulation was attenuated in cells co-treated with AUR. Finally, in vitro enzymatic assays showed that both AUR and GST inhibited partially purified PKC in a concentration-dependent manner. It is suggested that modulation of PKC represents a mechanism of action of gold coordination complexes at the cellular level.

Translocation of protein kinase C in porcine thyroid cells following exposure to thyrotropin.

We have previously shown that protein kinase C activators modulate differentiated thyroid function in vitro; however, how protein kinase C may be activated physiologically is unknown. The present studies were undertaken in order to determine whether TSH could activate protein kinase C in vitro. Following exposure of porcine thyroid cells to TSH, translocation of protein kinase C from the cytosol to its membrane-bound form was observed. Maximal translocation occurred at the lowest TSH concentration able to trigger this response (10 mU/ml) but persisted at higher concentrations (20-100 mU/ml). Time-course studies revealed that translocation of protein kinase C was seen only after 40 min. TSH could also produce a similar translocation in human neutrophils (known to have TSH receptors). In thyroid cells pre-treated with TSH, modulation of phorbol-mediated protein kinase C translocation was noted. These results indicate that TSH causes the translocation of protein kinase C in porcine thyroid cells (and possibly other TSH receptor-containing cells) and therefore may regulate the action of protein kinase C on differentiated thyroid function.

Gold compounds alter distribution of protein kinase C activity in human neutrophils.

Slow translocation of protein kinase C was observed by both auranofin and gold sodium thiomalate pretreatment of neutrophils. Both gold compounds failed to influence the activity of this enzyme directly when cell-free studies were performed. In intact neutrophils incubated with 5.1-20.3 microM auranofin, protein kinase C activity decreased in the cytosol in a time- and dose-dependent manner. Concomitantly, the levels of the membrane-associated protein kinase C were significantly elevated, although the amount of activity recovered could not account for that lost from the cytosol. Gold sodium thiomalate (5.0 microM-0.505 mM) demonstrated similar effects but with lesser potency than auranofin. In confirmation of previous results, phorbol myristate acetate (PMA), a cellular stimulus, also induced the translocation of protein kinase C. Key differences were that the reaction was rapid (occurring within minutes after PMA addition) and that relative recovery of kinase activity from the particulate fraction was fourfold greater. The relationship between gold compound-mediated kinase C redistribution and inhibition of neutrophil responses remains to be elucidated.

Use of fluoride ion as a probe for the guanine nucleotide-binding protein involved in the phosphoinositide-dependent neutrophil transduction pathway.

Fluoride activation of neutrophils was found to be associated with phosphoinositide turnover, as monitored by the time-dependent accumulation of inositol phosphates. Unlike phosphoinositide turnover induced by the chemotactic peptide, formylmethionylleucylphenylalanine, that induced by fluoride was not inhibited by pretreatment with pertussis toxin. The translocation of protein kinase C activity from the cytosolic to the membrane compartment was also observed in fluoride-stimulated cells. We have proposed that the mode of action of this halide ion involves interaction with a GTP-binding protein which serves as an intermediary unit between the receptors for inflammatory stimuli and the phosphoinositide-specific phosphodiesterase.

Effect of gold compounds on NADPH oxidase system of human neutrophils.

The inhibitory effects of gold compounds on the NADPH oxidase system of human polymorphonuclear leukocytes (PMNs) has been investigated. Auranofin (0.5-4.0 micrograms Au/ml) suppressed the rate of superoxide anion generation as well as the total yield in cells stimulated with phorbol myristate acetate and f-Met-Leu-Phe. This implies that drug action may be occurring at the level of protein kinase C or steps subsequent to this in the signal transduction sequence. Sodium aurothiomalate (1-100 micrograms Au/ml) lacked such activity. Neither gold compound altered the ability of the granule-rich fraction of PMNs to produce oxy radicals whether this fraction was obtained from drug-treated cells or was treated after its isolation. Therefore, in order for auranofin to exhibit its inhibitory effects on the NADPH oxidase system, an intact cell membrane is necessary.

Effects of gold compounds on leukotriene B4, leukotriene C4 and prostaglandin E2 production by polymorphonuclear leukocytes.

The effects of auranofin (AF) and sodium aurothiomalate (GSTM) on the production of specific arachidonic acid metabolites by chemotactic tripeptide activated polymorphonuclear leukocytes has been investigated using radioimmunoassay techniques. AF insignificantly enhanced the production of leukotrienes B4 and C4 at a concentration of 0.5 microgram Au/ml. However, at increasing concentrations, this drug suppressed the production of these metabolites in a dose dependent manner. In contrast, GSTM did not affect the production of either leukotriene at the concentrations tested. Of particular interest, prostaglandin E2 production was not affected by either gold compound. Both leukotrienes and prostaglandins are metabolized from arachidonic acid and are potent mediators of inflammation. The inhibition of leukotriene production may be another mechanism by which AF manifests its antiinflammatory effects in patients with rheumatoid arthritis.