miRNA-34 and miRNA-210 target hexamerin genes enhancing their differential expression during early brain development of honeybee (Apis mellifera) castes

During the honeybee larval stage, queens develop larger brains than workers, with morphological differentiation appearing at the fourth larval phase (L4), just after a boost in nutritional difference both prospective females experience. The molecular promoters of this caste-specific brain development are already ongoing in previous larval phases. Transcriptomic analyses revealed a set of differentially expressed genes in the L3 brains of queens and workers, which represents the early molecular response to differential feeding females receive during larval development. Three genes of this set, hex70b, hex70c and hex110, are more highly transcribed in the brain of workers than in queens. The microRNAs miR-34, miR-210 and miR-317 are in higher levels in the queens' brain at the same phase of larval development. Here, we tested the hypothesis that the brain of workers expresses higher levels of hexamerins than that of queens during key phases of larval development and that this differential hexamerin genes expression is further enhanced by the repressing activity of miR-34, miR-210 and miR-317. Our transcriptional analyses showed that hex70b, hex70c and hex110 genes are differentially expressed in the brain of L3 and L4 larval phases of honeybee queens and workers. In silico reconstructed miRNA-mRNA interaction networks were validated using luciferase assays, which showed miR-34 and miR-210 negatively regulate hex70b and hex110 genes by directly and redundantly binding their 3'UTR (untranslated region) sequences. Taken together, our results suggest that miR-34 and miR-210 act together promoting differential brain development in honeybee castes by downregulating the expression of the putative antineurogenic hexamerin genes hex70b and hex110.

Systemic ß adrenergic stimulation/ sympathetic nerve system stimulation influences intraocular RAS through cAMP in the RPE

Several lines of evidence support the existence of a renin-angiotensin system (RAS) in the retina that is separated from the blood stream by the retinal pigment epithelium (RPE). Under physiological conditions, increased activity of intraretinal RAS regulates neuronal activity of the retina but patho-physiologically participates in retinal degeneration such as hypertensive or diabetic retinopathy. Interestingly, the RPE appears to be a modulator of intraretinal RAS in response to changes in systemic RAS. As increased systemic RAS activity is associated with increased sympathetic tonus, we investigated whether systemic β-adrenergic stimulation of the RPE also modulates renin expression in the RPE. In vivo, the mouse RPE expresses the β-adrenergic receptor subtypes 1 and 2. Staining of retina sagittal sections showed tyrosine hydroxylase positive nerve endings in the choroid indicating adrenaline/noradrenaline production sites in close proximity to the RPE. Systemic infusion of isoproterenol increased renin expression in the RPE but not in the retina. This increase was sensitive to concomitant systemic application of the angiotensin-2 receptor-type-1 blocker losartan. In vitro analysis of renin gene expression using polarized porcine RPE showed that the activity of the renin promoter can be increased by cAMP stimulation (IBMX/forskolin) but was not influenced by angiotensin-2. Thus, with the identification of the β-adrenergic system we added a new regulator of the retinal RAS with relevance for retinal function and pathology. Furthermore, it appears that the RPE is not only a close interaction partner of the photoreceptors but also a regulator or retinal activity in general.

Multiphoton imaging reveals axial differences in metabolic autofluorescence signals along the kidney proximal tubule

Kidney proximal tubules (PTs) are densely packed with mitochondria, and defects in mitochondrial function are implicated in many kidney diseases. However, little is known about intrinsic mitochondrial function within PT cells. Here, using intravital multiphoton microscopy and live slices of mouse kidney cortex, we show that autofluorescence signals provide important functional readouts of redox state and substrate metabolism and that there are striking axial differences in signals along the PT. Mitochondrial NAD(P)H intensity was similar in both PT segment (S)1 and S2 and was sensitive to changes in respiratory chain (RC) redox state, whereas cytosolic NAD(P)H intensity was significantly higher in S2. Mitochondrial NAD(P)H increased in response to lactate and butyrate but decreased in response to glutamine and glutamate. Cytosolic NAD(P)H was sensitive to lactate and pyruvate and decreased dramatically in S2 in response to inhibition of glucose metabolism. Mitochondrial flavoprotein (FP) intensity was markedly higher in S2 than in S1 but was insensitive to changes in RC redox state. Mitochondrial FP signal increased in response to palmitate but decreased in response to glutamine and glutamate. Fluorescence lifetime decays were similar in both S1 and S2, suggesting that intensity differences are explained by differences in abundance of the same molecular species. Expression levels of known fluorescent mitochondrial FPs were higher in S2 than S1. In summary, substantial metabolic information can be obtained in kidney tissue using a label-free live imaging approach, and our findings suggest that metabolism is tailored to the specialized functions of S1 and S2 PT segments.

MicroRNA signatures characterizing caste-independent ovarian activity in queen and worker honeybees (Apis mellifera L.)

Queen and worker honeybees differ profoundly in reproductive capacity. The queen of this complex society, with 200 highly active ovarioles in each ovary, is the fertile caste, whereas the workers have approximately 20 ovarioles as a result of receiving a different diet during larval development. In a regular queenright colony, the workers have inactive ovaries and do not reproduce. However, if the queen is sensed to be absent, some of the workers activate their ovaries, producing viable haploid eggs that develop into males. Here, a deep-sequenced ovary transcriptome library of reproductive workers was used as supporting data to assess the dynamic expression of the regulatory molecules and microRNAs (miRNAs) of reproductive and nonreproductive honeybee females. In this library, most of the differentially expressed miRNAs are related to ovary physiology or oogenesis. When we quantified the dynamic expression of 19 miRNAs in the active and inactive worker ovaries and compared their expression in the ovaries of virgin and mated queens, we noted that some miRNAs (miR-1, miR-31a, miR-13b, miR-125, let-7 RNA, miR-100, miR-276, miR-12, miR-263a, miR-306, miR-317, miR-92a and miR-9a) could be used to identify reproductive and nonreproductive statuses independent of caste. Furthermore, integrative gene networks suggested that some candidate miRNAs function in the process of ovary activation in worker bees.

Seedling survival of Handroanthus impetiginosus (Mart ex DC) Mattos in a semi-arid environment through modified germination speed and post-germination desiccation tolerance

Uniform rapid seed germination generally forms a great risk for the plant population if subsequent intermittent precipitation causes desiccation and seedling death. Handroanthus impetiginosus can be found commonly in a wide range of biomes within Brazil including those that are semi-arid. Germination and early growth was studied to understand how germinated seeds survive under these stringent conditions. Accessions were sampled from four seasonally dry biomes in Brazil. Precipitation at the start of the rainy season in the Caatinga, a semi-arid biome, is less predictable and the number of successive dry days per dry interval in the first four months of the rainy season was higher than in the other studied biomes. Plants from the Caatinga produced thicker seeds and this trait concurred with slow germination and stronger osmotic inhibition of germination across the accessions, forming a stress avoidance mechanism in the Caatinga. Post-germination desiccation tolerance was high in the Caatinga accession, could be re-induced in accessions from biomes with more regular precipitation (Cerrado and transition zone), but remained poor in the Cerradão accession; thus forming a stress tolerance mechanism. Production of adventitious roots ascertained survival of all tested individuals from all four locations, even if protruded radicles did not survive desiccation, forming an additional stress tolerance mechanism. A sequence of stress avoidance and stress tolerance mechanisms in seeds and germinated seeds was associated with precipitation patterns in different biomes. These mechanisms purportedly allow rapid seedling establishment when conditions are suitable and enable survival of the young seedling when conditions are adverse.

Piezo1 in Smooth Muscle Cells Is Involved in Hypertension-Dependent Arterial Remodeling

The mechanically activated non-selective cation channel Piezo1 is a determinant of vascular architecture during early development. Piezo1-deficient embryos die at midgestation with disorganized blood vessels. However, the role of stretch-activated ion channels (SACs) in arterial smooth muscle cells in the adult remains unknown. Here, we show that Piezo1 is highly expressed in myocytes of small-diameter arteries and that smooth-muscle-specific Piezo1 deletion fully impairs SAC activity. While Piezo1 is dispensable for the arterial myogenic tone, it is involved in the structural remodeling of small arteries. Increased Piezo1 opening has a trophic effect on resistance arteries, influencing both diameter and wall thickness in hypertension. Piezo1 mediates a rise in cytosolic calcium and stimulates activity of transglutaminases, cross-linking enzymes required for the remodeling of small arteries. In conclusion, we have established the connection between an early mechanosensitive process, involving Piezo1 in smooth muscle cells, and a clinically relevant arterial remodeling.

Enhanced expression of ANO1 in head and neck squamous cell carcinoma causes cell migration and correlates with poor prognosis

Head and neck squamous cell carcinoma (HNSCC) has the potential for early metastasis and is associated with poor survival. Ano1 (Dog1) is an established and sensitive marker for the diagnosis of gastrointestinal stromal tumors (GIST) and has recently been identified as a Ca²⁺ activated Cl⁻ channel. Although the ANO1 gene is located on the 11q13 locus, a region which is known to be amplified in different types of human carcinomas, a detailed analysis of Ano1 amplification and expression in HNSCC has not been performed. It is thus still unclear how Ano1 contributes to malignancy in HNSCC. We analyzed genomic amplification of the 11q13 locus and Ano1 together with Ano1-protein expression in a large collection of HNSCC samples. We detected a highly significant correlation between amplification and expression of Ano1 and showed that HNSCC patients with Ano1 protein expression have a poor overall survival. We further analyzed the expression of the Ano1 protein in more than 4′000 human samples from 80 different tumor types and 76 normal tissue types and detected that besides HNSCC and GISTs, Ano1 was rarely expressed in other tumor samples or healthy human tissues. In HNSCC cell lines, expression of Ano1 caused Ca²⁺ activated Cl⁻ currents, which induced cell motility and cell migration in wound healing and in real time migration assays, respectively. In contrast, knockdown of Ano1 did not affect intracellular Ca²⁺ signaling and surprisingly did not reduce cell proliferation in BHY cells. Further, expression and activity of Ano1 strongly correlated with the ability of HNSCC cells to regulate their volume. Thus, poor survival in HNSCC patients is correlated with the presence of Ano1. Our results further suggest that Ano1 facilitates regulation of the cell volume and causes cell migration, which both can contribute to metastatic progression in HNSCC.

Airway epithelial cells--functional links between CFTR and anoctamin dependent Cl- secretion

Airways consist of a heterogeneous population of cells, comprising ciliated cells, Clara cells and goblet cells. Electrolyte secretion by the airways is necessary to produce the airway surface liquid that allows for mucociliary clearance of the lungs. Secretion is driven by opening of Cl(-) selective ion channels in the apical membrane of airway epithelial cells, through either receptor mediated increase in intracellular cAMP or cytosolic Ca(2+). Traditionally cAMP-dependent and Ca(2+)-dependent secretory pathways are regarded as independent. However, this concept has been challenged recently. With identification of the Ca(2+) activated Cl(-) channel TMEM16A (anoctamin 1) and with detailed knowledge of the cAMP-regulated cystic fibrosis transmembrane conductance regulator (CFTR), it has become possible to look more closely into this relationship.

Anoctamin 6 is an essential component of the outwardly rectifying chloride channel

Outwardly rectifying chloride channels (ORCC, ICOR) of intermediate single-channel conductance of around 50 pS, are ubiquitously expressed, but have remained a mystery since their description more than 25 y ago. These channels have been shown to be activated on membrane excision and depolarization of the membrane voltage and by cAMP in the presence of the cystic fibrosis transmembrane conductance regulator. We show that anoctamin 6 (Ano6), a member of the recently identified family of putative Cl(-) channels, is the crucial component of ORCC single-channel and whole-cell currents in airway epithelial cells and Jurkat T lymphocytes. Cystic fibrosis transmembrane conductance regulator augmented ORCC produced by Ano6 in A549 airway epithelial cells. Ano6 is activated during membrane depolarization or apoptosis of Jurkat T lymphocytes and epithelial cells, and is inhibited by 5-nitro-2-(3-phenylpropylamino) benzoic acid, 4,4'-diisothio-cyanostilbene-2,2'-disulfonic acid, or AO1. Ano6 belongs to the basic equipment of any cell type, including colonic surface epithelial cells. It forms the essential component of ORCC and seems to have a role for cell shrinkage and programmed cell death.

Schistosomiasis mansoni: ultrasound-evaluated hepatic fibrosis and serum concentrations of hyaluronic acid

Schistosomiasis mansoni is a fibrogenic liver disease that constitutes a major health problem in north-eastern Brazil. Although one common manifestation of the disease, periportal fibrosis (PPF), can be assessed by ultrasonography by well-trained physicians, the necessary equipment and personnel are not always readily available. Serum markers, including hyaluronic acid (HA), have been used as alternative means of measuring fibrosis. Recently serum concentrations of HA have been evaluated in 77 Brazilians (61 cases of schistosomiasis mansoni and 16 healthy controls) and compared against the ultrasound-evaluated PPF in the same subjects. The HA was measured using a non-competitive fluorescence-based assay, while the PPF was explored using a portable ultrasound scanner (SSD-500; Aloka, Tokyo) and graded, as patterns A-F, according to the World Health Organization's 'Niamey protocol'. In general, the serum concentrations of HA were found to be positively correlated with the severity of the PPF. The mean concentration of HA in the sera of the 16 controls was significantly lower than that recorded in the schistosomiasis cases who showed PPF of patterns D or E (P<0·001 for each). The cases who showed pattern-C PPF also had significantly less HA in their sera than the cases with PPF of patterns D or E (P<0·001 for each), and the cases with pattern-D fibrosis had significantly lower HA concentrations in their sera than the cases with PPF of pattern E (P<0·001). In an analysis based on a receiver-operating-characteristic (ROC) curve, an HA concentration of 20·2 μg/litre of serum was identified as a threshold that could be used to distinguish moderate cases of PPF (i.e. patterns C or D) from the more advanced cases (i.e. patterns E or F), with a sensitivity of 60% and specificity of 65%. In conclusion, it appears that serum concentrations of hyaluronic acid could be used as markers for periportal fibrosis in patients with schistosomiasis mansoni.

Expression and function of epithelial anoctamins

Endogenous Ca(2+)-activated Cl(-) currents (CaCCs) are abundant and present in very different cell types. Very good evidence has been provided that endogenous CaCC is produced by anoctamin 1 (Ano1) and Ano2. Insight into the physiological role of anoctamins has been provided for Ano1, Ano2 and Ano6; however, the physiological role of the other seven members of the anoctamin family remains obscure. Anoctamins 1 and 2 may operate as individual Ca(2+)-sensitive channel proteins or may require accessory subunits for complete function. We find that overexpressed Ano1 has properties resembling all those of endogenous CaCCs, although with some noticeable biophysical and regulatory differences when compared with endogenous channels. Apart from Ano1 and Ano2, expression of Ano6 also produces a Cl(-) conductance. Depending on the cellular background, Ano6 currents may have variable properties. Anoctamins 1 and 6 are frequent in epithelial cells, often coexpressed together with Ano8, Ano9 and Ano10. Most available data on anoctamins were obtained from mouse tissues and from cultured cells, which may not be representative of native human tissues.

Occurrence of Ornithodoros brasiliensis Aragão (Acari: Argasidae) in São Francisco de Paula, RS, Southern Brazil

There have been no reports of the endemic Ornithodoros brasiliensis (Aragão) in Rio Grande do Sul, southern Brazil, since the 1950s. In January 2007, 21 O. brasiliensis ticks were collected in a rural area named "Cruzinha" in the municipality of São Francisco de Paula, RS, and another population was sampled later that year (October) in Vargem do Cedro, another rural area of São Francisco de Paula, following reports of human parasitism by ticks. The reappearance of this tick is a reason for concern in terms of public health.

Bestrophin 1 promotes epithelial-to-mesenchymal transition of renal collecting duct cells

Bestrophin 1 (Best1) controls intracellular Ca(2+) concentration, induces Ca(2+)-activated Cl(-) conductance, and increases proliferation of colon carcinoma cells. Here, we show that expression of Best1 in mouse renal collecting duct (CD) cells causes i) an increase in cell proliferation, ii) a loss of amiloride-sensitive Na(+) absorption, iii) induction of Ca(2+)-dependent Cl(-) conductance (CaCC), and iv) epithelial-to-mesenchymal transition. During conditions of high proliferation or when we exposed CD cells to serum or TGF-beta1, we observed upregulation of Best1, increased CaCC, redistribution of the epithelial-to-mesenchymal transition marker beta-catenin, and upregulation of vimentin. In contrast, suppression of Best1 by RNAi inhibited proliferation, reduced CaCC, and downregulated markers of EMT. CaCC and expression of Best1 were independent of the cell cycle but clearly correlated to cell proliferation and cell density. During renal inflammation in LPS-treated mice or after unilateral ureteral obstruction, we observed transient upregulation of Best1. These data indicate that repression of cell proliferation, CaCC, and expression of Best1 occurs during mesenchymal-to-epithelial transition once CD cells polarize and terminally differentiate. These results may suggest a role for Best1 in renal fibrosis and tissue repair.

Ticks (Ixodidae) on humans in South America

Twenty eight species of Ixodidae have been found on man in South America (21 Amblyomma, 1 Boophilus, 2 Dermacentor, 2 Haemaphysalis, 1 Ixodes and 1 Rhipicephalus species). Most of them are rarely found on man. However, three species frequently parasitize humans in restricted areas of Argentina (A. neumanni reported from 46 localities), Uruguay (A. triste from 21 sites) and Argentina-Brazil (A. parvum from 27 localities). The most widespread ticks are A. cajennense (134 localities in Argentina, Bolivia, Brazil, Colombia, Ecuador, French Guiana, Guyana, Paraguay, Suriname and Venezuela), A. ovale (37 localities in Argentina, Brazil, Ecuador, French Guiana, Guyana, Paraguay, Suriname and Venezuela) and A. oblongoguttatum (28 sites in Brazil, Colombia, French Guiana, Guyana, Suriname and Venezuela). Amblyomma aureolatum (18 localities in Argentina, Brazil, French Guiana and Paraguay), A. cajennense, and A. triste are vectors of rickettsioses to man in South America. A better understanding of the respective roles of these and other tick species in transmitting pathogens to humans will require further local investigations. Amblyomma ticks should be the main subjects of these studies followed by species of Boophilus, Dermacentor, Haemaphysalis and Rhipicephalus species. In contrast with North America, Europe and Asia, ticks of the genus Ixodes do not appear to be major players in transmitting diseases to human. Indeed, there is only one record of an Ixodes collected while feeding on man for all South America.

Serum laminin, type IV collagen and hyaluronan as fibrosis markers in non-alcoholic fatty liver disease

Hepatic fibrosis in patients with non-alcoholic fatty liver disease is associated with progression of the disease. In the present study, we analyzed the discriminative ability of serum laminin, type IV collagen and hyaluronan levels to predict the presence of fibrosis in these patients. In this preliminary report, we studied 30 overweight patients divided into two groups according to the absence (group I, N = 19) or presence (group II, N = 11) of fibrosis in a liver biopsy. Triglycerides, aspartate aminotransferase, alanine aminotransferase, gamma-glutamyltranspeptidade, hyaluronan (noncompetitive fluoroassay), type IV collagen, and laminin (ELISA) were determined. Group II presented significantly higher mean laminin, hyaluronan, type IV collagen, and aspartate aminotransferase values, which were due to the correlation between these parameters and the stage of fibrosis in the biopsy (Spearman's correlation coefficient, rS = 0.65, 0.62, 0.53, and 0.49, respectively). Analysis of the ROC curve showed that laminin values >282 ng/ml were those with the best diagnostic performance, with 87% accuracy. Association of laminin with type IV collagen showed improvement in the positive predictive value (100%), but with reduction in diagnostic sensitivity (64%). When compared with the criteria of Ratziu et al. for the diagnosis of septal fibrosis, laminin values presented a better diagnostic accuracy (83 vs 70%). Determination of extracellular matrix components in serum, especially of laminin, may identify patients with non-alcoholic fatty liver disease and fibrosis and these components may be used as indicators for liver biopsy in these patients.

Amblyomma aureolatum (Pallas, 1772) and Amblyomma ovale Koch, 1844 (Acari: Ixodidae): hosts, distribution and 16S rDNA sequences

DNA sequences of Amblyomma aureolatum (Pallas, 1772) and Amblyomma ovale Koch, 1844 were obtained to determine genetic differences between these tick species. Collections of these species are discussed in relation to distribution and hosts. Seven ticks collections (four from Brazil, one from Argentina, one from Uruguay and one from USA) house a total of 1272 A. aureolatum (224 males, 251 females, 223 nymphs and 574 larvae) and 1164 A. ovale (535 males, 556 females, 66 nymphs and 7 larvae). The length of the sequenced mitochondrial 16S rRNA gene fragment for A. aureolatum was 370bp and for A. ovale was 373bp. The DNA sequence analysis showed a 13.1% difference between the two species. Apart from one male A. ovale found on a toad, all adult ticks were found on mammals. The majority of adult specimens of both tick species were removed from Carnivora (96.1 and 84.3% of A. aureolatum and A. ovale, respectively), especially from dogs (53.1% of A. aureolatum, and 46.4% of A. ovale). Collections on wild Canidae were higher for A. aureolatum (23.3%) than for A. ovale (7.1%). On the other hand, collections of A. ovale adults on wild Felidae were higher (18.3%) than findings of A. aureolatum (9.2%). The contribution of other mammalian orders as hosts for adults of A. aureolatum and A. ovale was irrelevant, with the exception of Perissodactyla because Tapiridae contributed with 13.0% of the total number of A. ovale adults. Adults of both tick species have been found occasionally on domestic hosts (apart of the dog) and humans. Most immature stages of A. aureolatum were found on Passeriformes birds, while rodents and carnivores were the most common hosts for nymphs and larvae of A. ovale. A. aureolatum has been found restricted to the Neotropical region, covering the eastern area of South America from Uruguay to Surinam, including northeastern Argentina, eastern Paraguay, southeastern Brazil and French Guiana. A. ovale showed a distribution that covers the Neotropical region from central-northern Argentina throughout the Neotropics into the Nearctic region of Mexico with a few records from the USA, also with collection sites in Paraguay, Bolivia, most Brazilian states, Peru, Ecuador, French Guiana, Surinam, Guyana, Trinidad & Tobago, Venezuela, Colombia, Panama, Costa Rica, Nicaragua, Belize, Guatemala and several states of Mexico.

Partial strategic tick control within a herd of European breed cattle in the state of Rio Grande do Sul, southern Brazil

A trial is described, in the state of Rio Grande do Sul, southern Brazil, as one of a series suggested to investigate the effects of strategic but selective acaricide treatments of cattle within herds against Boophilus microplus. They are aimed at considering the repercussions of farmer attempts at immediate reductions in acaricide costs and the potential for creation of 'refugia' of untreated ticks. Half (Group 1) of a small experimental herd of European breed heifers were treated strategically against ticks, three times during the late spring-early summer and twice during autumn (southern hemisphere), with an injectable avermectin endectocide, designed to act directly against the first and third generations of parasitic B. microplus per 'cattle tick year' at this site, respectively. The consequent levels of infestations on all of the member cattle in their common pasture were monitored. Group 1 showed low to zero tick counts during the 28-day treatment interval periods and up to ca. 14 days after the last of such a series. Treated cattle, however, became re-infested outside of these periods and to levels that would be considered as unacceptable by farmers in the state. The untreated cattle (Group 2) showed infestations at generally higher levels, than their contemporaries, within and outside of the treatment periods. There were thus ample sources of larvae in the pasture, derived principally from falling, untreated engorged female ticks, re-infesting both the treated and untreated cattle. Advantages of maintaining chemically untreated cattle ticks within a herd, compared to their disadvantages as contaminants to classical strategic control procedures, merit re-evaluation, especially in relation to the recent, world-wide resurgence of acaricide resistance in B. microplus.

Toxicity of cypermethrin and diazinon to Haematobia irritans (Diptera: Muscidae) in its American southern range

Synthetic pyrethroids are considered currently less effective than organophosphate insecticides for controlling Haematobia irritans on cattle in its American southern range. To test the validity of this hypothesis, horn fly populations from 95 cattle herds in central-northern Argentina and southern Brazil were evaluated to determine 50% lethal concentrations (LC(50)) to cypermethrin and diazinon, respectively. Horn flies were exposed to filter papers and glass vials treated with cypermethrin and diazinon, respectively, and LC(50) values were determined using probit analysis. Two and 78 fly populations showed LC(50) values indicating susceptibility and resistance to cypermethrin, respectively, in comparison to historical LC(50) values obtained when the horn fly populations were susceptible to cypermethrin. Five fly populations had an undetermined resistance status to cypermethrin. The diazinon tests showed no obvious indications of H. irritans resistance. Thirty nine percent of farmers still rely on pyrethroids to control horn fly populations on cattle which represents a decreasing proportion from a few years ago when horn fly control was carried out using pyrethroids almost exclusively. Organophosphates could provide control for horn flies resistant to pyrethroids; however, the reliance on chemicals alone to control H. irritans is not considered a proper approach for the future.

Babesiosis (Babesia bovis) stability in unstable environments

Enzootic stability (herd immunity) in bovine babesiosis occurs when the rate of transmission (inoculation rate) of Babesia spp by the tick vector is sufficient to immunize a majority of susceptible calves before the loss of calfhood resistance. The effect of three tick (Boophilus microplus) control strategies (none, threshold, and strategic) on enzootic stability and the likelihood of babesiosis (Babesia bovis) outbreaks was studied using a spreadsheet age-class computer simulation model. The model was driven by weekly bovine tick counts from Brazil and Uruguay. The Eldorado do Sul, RS, Brazil bovine population (30 degrees 05' South latitude) was found to be in a naturally occurring state of enzootic stability, corresponding to an inoculation rate exceeding 0.005 throughout the year. Threshold dipping strategies should not increase the risk of babesiosis in cattle so managed. Strategic dipping resulted in an extended period of enzootic instability lasting 30 weeks, which requires protection of the herd through immunization. Because of the more prolonged low winter temperature conditions, the Tacuarembó, Uruguay bovine population (31 degrees 40' South latitude) was found to be in a naturally occurring state of enzootic instability, characterized by a 28 week period in which the inoculation rate was below 0.005. Strategic dipping should lead to eradication of the babesial parasite from tick and bovine populations, but would not result in eradication of the tick vector. This could lead to subsequent outbreaks if Babesia carrier animals were to be introduced into the herd. In both populations, strategic tick control could be accompanied by concurrent babesiosis vaccination.

Remaining small bowel length: association with catheter sepsis in patients receiving home total parenteral nutrition: evidence of bacterial translocation

Patients with short bowel syndrome (SBS) receiving total parenteral nutrition (TPN) have a high incidence of catheter-related sepsis, one of its major complications. The aim of this study was to correlate the length of remaining small bowel (RSB) with septic episodes related to the central venous catheter in a group of patients with severe SBS with home TPN. The length of the RSB (<50 cm or > or = 50 cm) was related to the frequency of catheter sepsis, time until the first episode, and the agents responsible in eight SBS patients receiving home TPN. There were 13 episodes of catheter infection (0.88 per patient-year). The group with a shorter RSB length (five patients) presented 1.3 to 2.76 infections/year and 2 to 9 months until the first episode, compared to 0 to 0.75 infections/ year (p = 0.0357) and 11 to 65 months until the first episode (p = 0.0332) in the group with the longer RSB. In the first group, the agents isolated were Enterobacteriae (Enterobacter sp., Klebsiella sp., Pseudomonas sp., and Proteus sp.) in eight episodes and Candida sp. in one. In the latter sepsis was caused by Staphylococcus sp. in three episodes and Pseudomonas sp. in one. Therefore patients with remaining small bowel shorter than 50 cm have a higher frequency of catheter-related sepsis, particularly by enteric microorganisms. This might be an evidence of the occurrence of bacterial translocation and its role in the pathogenesis of catheter-related sepsis in patients with an extremely short RSB receiving home TPN.

A review of the ticks (Acari, ixodida) of Brazil, their hosts and geographic distribution - 1. The state of Rio Grande do Sul, southern Brazil

A review of the ticks (Acari, Ixodida) of the State of Rio Grande do Sul, southern Brazil, was completed as a step towards a definitive list (currently indicated as 12) of such species, their hosts and distribution. The ticks: Argas miniatus (poultry), Ixodes loricatus (opossums), Amblyomma aureolatum (dogs), A. calcaratum (anteaters), A. cooperi (capybaras), A. nodosum (anteaters), A. tigrinum (dogs) (Neotropical) and Rhipicephalus sanguineus (dogs) (introduced, cosmopolitan, Afrotropical) were confirmed as present, in addition to the predominant, Boophilus microplus (cattle) (introduced, pan-tropical, Oriental). Of the further 18 species thus far reported in the literature as present in the state, but unavailable for examination: only Ornithodoros brasiliensis (humans and their habitations) (Neotropical), Ixodes affinis (deer) (Nearctic/Neotropical) and I. auritulus (birds) (Nearctic/Neotropical/Afrotropical/ Australasian) are considered likely; 13 species would benefit from corroborative local data but the majority appear unlikely; reports of A. maculatum (Nearctic/Neotropical, but circum-Caribbean) are considered erroneous; the validity of A. fuscum is in doubt. The very recent, first known report of the tropical Anocentor nitens (horses)(Nearctic/Neotropical), but still apparent absence of the tropical A. cajennense (catholic) (Nearctic/Neotropical) and the sub-tropical/temperate Ixodes pararicinus (cattle) (Neotropical) in Rio Grande do Sul are important for considerations on their current biogeographical distribution and its dynamics in South America. The state has relatively long established, introduced ("exotic"), Old World tick species (B. microplus, R. sanguineus) that continue to represent significant pests and disease vectors to their traditional, introduced domestic animal hosts, cattle and urban dogs. There are also indigenous, New World ticks (A. miniatus, O. brasiliensis, A. aureolatum, A. nitens), as both long established and possibly newly locally introduced species in the state, that should be considered as potential and emergent pests and pathogen vectors to humans and their more recently acquired, introduced domestic animal hosts; rural poultry, dogs and horses.

Patients with head and neck tumors excrete a chondroitin sulfate with a low degree of sulfation: a new tool for diagnosis and follow-up of cancer therapy

The chondroitin sulfate excreted in the urine of 10 patients with cancer of the head and neck and 27 healthy subjects was analyzed. The disaccharide products formed from chondroitin sulfate excreted by these 10 patients by action of chondroitinase ABC show a significant (P < 0.0001) relative increase of nonsulfated disaccharide (35.6% +/- 5.7%) when compared with the nonsulfated disaccharide (10.0% +/- 0.9%) present in the chondroitin sulfate of 27 healthy subjects. In 6 patients the structure of the excreted compound was analyzed up to 4 months after surgery. After removal of the cancer, the percent amounts of the nonsulfated disaccharide tend to approach the values found for the chondroitin sulfate of healthy subjects. A significant (P < 0.0001) change in the ratio of urinary chondroitin sulfate and heparan sulfate and a decrease in the electrophoretic migration of chondroitin sulfate were also observed. All of the patients with head and neck cancer analyzed so far have shown this structural anomaly of urinary chondroitin sulfate. This assay may be useful in the diagnosis and follow-up of cancer therapy.

[Drug treatment for stable coronary artery disease at primary and tertiary medical centers]

PURPOSE

To observe the distribution of the main drugs used in patients with stable coronary heart disease, in primary and tertiary medical care centers (MCC).

METHODS

We studied 300 consecutive out patients at the Hetat Institute with the diagnosis of stable coronary artery disease, 205 (68%) males and 95 (32%) female, aged from 31 to 80 (mean 58 +/- 8.0) years old. Drug intake was evaluated.

RESULTS

We observed that the use of nitrates (48% vs 55%; p = NS) and calcium antagonists (46% vs 37%; p = NS), respectively in both primary and tertiary MCC was similar. The beta blockers were used more often in the primary MCC (50% vs 35%; p = 0.02). Angiotensin converting enzyme inhibitors (11% vs 42%; p < 0.001), diuretics (30% vs 49%; p = 0.002) and aspirin (44% vs 76%; p = 0.0001) were more frequently used in the tertiary MCC.

CONCLUSION

We observed similar frequency of use of nitrates and calcium antagonists in both centers. There was a higher use of beta blockers in primary MCC. The angiotensin converting enzyme inhibitors and antiplatelet agents were more used in the tertiary MCC. In relation to the updated literature, the best pharmacotherapy to coronary artery disease should be optimized in both centers.

Acute renal failure due to rhabdomyolysis in diabetic patients

We report a 32-year-old Black man, admitted to the ICU with coma and severe metabolic disturbances due to diabetic ketoacidosis. During the admission, rhabdomyolysis and acute renal failure (ARF) were diagnosed. After metabolic control and gradual decrease of creatine kinase levels, he presented a progressive improvement of renal function. We emphasize nontraumatic rhabdomyolysis as a poorly recognized pathogenetic factor for ARF in diabetic ketoacidosis and suggest that a better understanding of its mechanisms and an early application of protective measures is necessary.

Anomalous structure of urinary chondroitin sulfate from cancer patients. A potential new marker for diagnosis of neoplasias

BACKGROUND

Chondroitin sulfate is significantly increased in tumors (10 to 100 times) when compared to the amounts present in normal adjacent tissues. To investigate if the changes in concentration of chondroitin sulfate could be reflected in the urine of cancer patients we have analyzed the chondroitin sulfate excreted by 44 patients with different types of tumors, 50 normal individuals and 15 patients with unrelated diseases.

EXPERIMENTAL DESIGN

The identification and structural analyses of the sulfated glycosaminoglycans were made by electrophoresis and degradation with specific enzymes (chondroitinases AC and ABC), identification/quantitation of their disaccharide products by chromatography (paper and HPLC) and chemical determinations.

RESULTS

The disaccharide products formed from chondroitin sulfate of the 44 cancer patients by action of chondroitinase ABC show a substantial relative increase of non sulfated disaccharide (32.1% +/- 15.2) with a relative decrease of 6-sulfated disaccharide (28.9% +/- 11.5) and 4-sulfated disaccharide (39.0% +/- 13.5) when compared to the chondroitin sulfate of normal subjects (9.1% +/- 2.2, 40.6% +/- 4.5 and 50.2% +/- 4.5, respectively) or from patients with unrelated diseases. There is a direct correlation between the non sulfated disaccharide content and the stage of malignancy of the cancer patients. A significant change of the ratio of chondroitin sulfate and heparan sulfate and a decrease in the electrophoretic migration of chondroitin sulfate were also observed in cancer patients.

CONCLUSIONS

All the cancer patients analyzed so far have shown the structural anomaly of the urinary chondroitin sulfate and this may be useful in the diagnosis and follow up of cancer therapy.

[Effect of ticlopidine and dipyridamole on platelet aggregation and count in patients with chronic stable angina pectoris]

PURPOSE

To compare the ticlopidine and dipyridamole effects on platelets count and aggregation in patients with stable coronary artery disease.

PATIENTS AND METHODS

Eighty patients with stable coronary artery disease and mean of 58.3 +/- 5.8 years were studied. They were divided into two equal groups of 40 patients and each one treated with ticlopidine or dipyridamole. Platelets count and aggregation were examined before treatment and at first and fourth weeks of treatment.

RESULTS

At the end of fourth week of treatment, spontaneous, induced by ADP or by adrenalin platelet aggregation inhibition was observed, respectively, in 82.5%, 72.5% e 67.5% of the patients in ticlopidine group. The spontaneous, induced by ADP or by adrenalin, platelet aggregation inhibition in the patients of dipyridamole group was, respectively, 40%, 30% e 27.5% (p less than 0.001). The platelets count did not change in both groups.

CONCLUSION

The ticlopidine effect is much more evident in platelet aggregation inhibition than dipyridamole, and maybe a choice in the prevention of cardiovascular events.