Experimental infection by Anaplasma marginale in buffaloes and cattle: clinical, hematological, molecular and pathological aspects / Infecção experimental de Anaplasma marginale em búfalos e bovinos: aspectos clínicos, hematológicos, moleculares e patológicos

The study aimed to evaluate and compare the clinical, laboratory and pathological aspects of buffalo and bovine experimentally infected with AmRio 2 strain of Anaplasma marginale. Four Murrah buffaloes and four crossbred cattle were used in the experiment, which two animals of each species were splenectomized. Strain AmRio 2 of A. marginale was inoculated in all experimental animals. Clinical exams, Packed Cell Volume (PCV), blood counts, blood smears, rickettsemia, necropsy and histopathology were performed in all cases. Semi-Nested-PCR (snPCR) for the msp5 and snPCR for the msp1α target gene for identification of A. marginale in blood samples from animals was done. From positive samples for msp1α snPCR, samples were analyzed for the amino acid sequences of this gene. Two splenectomized cattle presented apathy, pale mucous membranes, jaundice, hyperthermia, and severe anemia. The remaining experimental animals did not show clinical signs. The rickettsemia in all animals was less than 1%. The mean PCV of the splenectomized cattle was below 20% at two-time points after infection. On the blood count, the main changes were observed in splenectomized calves and were characterized by a decrease in red blood cells, hemoglobin, PCV and platelets (p <0.05). All animals presented leukocyte elevation by increased lymphocytes, however, with no significant difference. The average prepatent period was two days in all the animals. The average incubation period in cattle that became ill was 25.5 days, and death occurred, on average, 63 days after inoculation of the strain. The necropsy findings were characterized by pale carcass, ascites, enlarged liver, distended gallbladder, and thick bile. Histopathological findings included infiltration of macrophages and lymphocytes in various organs, hepatic sinusoidal dilatation, and necrosis of the large intestine. In snPCR for the msp5 gene, 100% of the animals were positive in at least one evaluation. And in the snPCR for the infection of the msp1α target gene was also found in all animals in at least one sample evaluated. However, sequencing revealed only five animals, including the bovine which died, with a similarity of the amino acid sequences with AmRio 2 strain of A. marginale. It is concluded that the splenectomized cattle died due to anaplasmosis caused by the inoculated strain and the buffalo were more resistant compared to cattle. Buffaloes can be an alternative to cattle rearing in areas with a high occurrence of clinical cases of anaplasmosis.(AU)

O estudo teve como objetivo avaliar e comparar os aspectos clínicos, laboratoriais e patológicos de búfalos e bovinos infectados experimentalmente com estirpe AmRio 2 de Anaplasma marginale. Para isso, foram utilizados quatro bubalinos Murrah e quatro bovinos mestiços, sendo dois animais de cada espécie, esplenectomizados. Estirpe AmRio 2 de A. marginale foi inoculada em todos os animais. Foram realizados exames clínicos, hematócrito, hemograma, esfregaço sanguíneo com avaliação de riquetsemia, necropsia e histopatologia, além de, Semi-Nested-PCR (snPCR) para o gene alvo msp5 e snPCR para o gene alvo msp1α para identificação de A. marginale nas amostras de sangue dos ruminantes. A partir das amostras positivas na snPCR msp1α, foram selecionadas amostras para análise das sequências de aminoácidos deste gene. Dois bovinos esplenectomizados apresentaram apatia, mucosas pálidas, icterícia, hipertermia e anemia severa. O restante dos animais não apresentou sintomatologia clínica. A riquetsemia em todos os animais foi menor que 1%. A média do hematócrito dos bovinos esplenectomizados esteve abaixo de 20% em dois momentos após infecção. Ao hemograma, as principais alterações observadas foram nos bovinos esplenectomizados e caracterizaram-se por redução de hemácias, hemoglobina, hematócrito e plaquetas (p<0,05). Todos os animais apresentaram elevação de leucócitos por aumento de linfócitos, porém, sem diferença significativa. O período pré-patente médio foi de dois dias em todos os animais. O período de incubação médio nos bovinos que adoeceram foi de 25,5 dias e estes morreram em média 63 dias após inoculação da estirpe. Os achados de necropsia caracterizaram-se por carcaça pálida, ascite, aumento de volume do fígado, vesícula biliar distendida e bile espessa. À histopatologia, verificou-se infiltração de macrófagos e linfócitos em diversos órgãos, dilatação dos sinusoides hepáticos e necrose do intestino grosso. A snPCR para o gene msp5, revelou 100% dos animais positivos em pelo menos um momento de avaliação. E na snPCR para o gene alvo msp1α também verificou-se infecção em todos os animais em pelo menos uma amostra avaliada. Entretanto, o sequenciamento revelou apenas cinco animais, incluindo os bovinos que morreram, com similaridade das sequências de aminoácidos com estirpe AmRio 2 de A. marginale. Conclui-se que os bovinos esplenectomizados morreram em virtude de anaplasmose provocada pela estirpe inoculada e os bubalinos foram mais resistentes em comparação aos bovinos. Finalmente, os búfalos podem ser uma alternativa à criação de bovinos em áreas com alta ocorrência de casos clínicos de anaplasmose.(AU)

Morphology and Morphometry of the Midgut in the Stingless Bee Friesella schrottkyi (Hymenoptera: Apidae).

Friesella schrottkyi is a small stingless bee (3-mm long) important for agricultural and native forest pollination. This study describes the morphology and morphometry of the midgut in F. schrottkyi forager workers. The F. schrottkyi midgut presents a single-layered epithelium with digestive, regenerative and endocrine cells. The digestive cells are similar along the entire midgut length with a spherical nucleus, apex with long striated border, cytoplasmic granules in the apical region and well-developed basal labyrinth associated with mitochondria, suggesting they are multifunctional, synthesizing digestive enzymes and peritrophic matrix compounds and absorbing nutrients. Regenerative cells are located around the basal region organized in nests with some cells with a spherical nucleus. Phe-Met-Arg-Phe-NH2-amide (FMRFamide) positive endocrine cells are restricted to the posterior midgut region, suggesting a paracrine function in the midgut. This is the first morphological description of the F. schrottkyi midgut contributing to the comprehension of the digestive process of this bee.

Absolute timing of the photoelectric effect.

Photoemission spectroscopy is central to understanding the inner workings of condensed matter, from simple metals and semiconductors to complex materials such as Mott insulators and superconductors1. Most state-of-the-art knowledge about such solids stems from spectroscopic investigations, and use of subfemtosecond light pulses can provide a time-domain perspective. For example, attosecond (10-18 seconds) metrology allows electron wave packet creation, transport and scattering to be followed on atomic length scales and on attosecond timescales2-7. However, previous studies could not disclose the duration of these processes, because the arrival time of the photons was not known with attosecond precision. Here we show that this main source of ambiguity can be overcome by introducing the atomic chronoscope method, which references all measured timings to the moment of light-pulse arrival and therefore provides absolute timing of the processes under scrutiny. Our proof-of-principle experiment reveals that photoemission from the tungsten conduction band can proceed faster than previously anticipated. By contrast, the duration of electron emanation from core states is correctly described by semiclassical modelling. These findings highlight the necessity of treating the origin, initial excitation and transport of electrons in advanced modelling of the attosecond response of solids, and our absolute data provide a benchmark. Starting from a robustly characterized surface, we then extend attosecond spectroscopy towards isolating the emission properties of atomic adsorbates on surfaces and demonstrate that these act as photoemitters with instantaneous response. We also find that the tungsten core-electron timing remains unchanged by the adsorption of less than one monolayer of dielectric atoms, providing a starting point for the exploration of excitation and charge migration in technologically and biologically relevant adsorbate systems.

Ultrafast hydrogen bond dynamics and partial electron transfer after photoexcitation of diethyl ester of 7-(diethylamino)-coumarin-3-phosphonic acid and its benzoxaphosphorin analog.

The solvation dynamics after optical excitation of two phosphono-substituted coumarin derivatives dissolved in various solutions are studied by fluorescence up-conversion spectroscopy and quantum chemical simulations. The Kamlet-Taft analysis of the conventional absorption and emission spectra suggests weakening of the solvent-solute H-bonds upon optical excitation, which is in contrast to the results gained by the quantum simulations and earlier studies reported for coumarin derivatives without phosphono groups. The simulations give evidence that the solvent reorganisation around the excited fluorophore leads to partial electron transfer to the first solvation shell. The process occurs on a timescale between 1 and 10 ps depending on the solvent polarity and leads to a fast decay of the time-resolved emission signal. Using the ultrafast spectral shift of the time-dependent fluorescence we estimated the relaxation time of the H-bonds in the electronically excited state to be about 0.6 ps in water, 1.5 ps in ethanol and 2.8 ps in formamide.

Haplotype TGTG from SNP 45T/G and 276G/T of the adiponectin gene contributes to risk of polycystic ovary syndrome.

BACKGROUND: Haplotypes of adiponectin gene single nucleotide polymorphisms (SNP) might be related to metabolic disorders. AIM: To assess whether the prevalence of SNP 45T/G and 276G/T of the adiponectin gene and their haplotypes differ between polycystic ovary syndrome (PCOS) and non-hirsute cycling controls and to investigate the relationship between these haplotypes and risk factors for cardiovascular disease. SUBJECTS AND METHODS: In this case-control study, 80 women with PCOS and 1500 non-hirsute controls with regular cycles underwent clinical and laboratory measurements. Genotype distribution was analyzed by conventional PCR-restriction fragment length polymorphism. RESULTS: Compared to controls, PCOS women had greater body mass index (BMI) (31.0±7.9 kg/m² vs 23.4±4.6 kg/m²; p<0.001), waist circumference (92.2±18.8 cm vs 74.5±10.2 cm; p<0.001), and systolic and diastolic blood pressure (124.6±19.9 vs 111.5±13.0 mmHg and 79.2±12.5 vs 71.8±10.6 mmHg; p<0.025), as well as a worse lipid profile (p<0.007), even after adjustment for age and BMI. Genotype distribution was similar in PCOS and controls (45T/G: p=0.399; 276G/T: p=0.135). Six haplotypes were inferred and their frequencies differed significantly between the groups (p=0.001). The TGTG haplotype was more frequent in PCOS than controls (41.3 vs 18.9%). In PCOS, the GG genotype for SNP 276 (p=0.031) and the TGTG haplotype (p=0.023) were associated with higher systolic blood pressure vs other genotypes and haplotypes. Body composition, glucose, insulin, and lipid profile were similar across genotypes and haplotypes in both groups. CONCLUSIONS: Haplotype TGTG from adiponectin gene variants 45T/G and 276G/T is related to susceptibility to PCOS, and might be associated with increased blood pressure in PCOS.

Multifocal cutaneous ORF virus infection in goats in the Amazon region, Brazil.

Orf virus is the etiological agent of contagious ecthyma, a severe exanthematic disease that affects small ruminants. Orf virus is zoonosis that is associated with occupational contact with infected animals in human disease. Clinically, contagious ecthyma is characterized by the appearance of vesicles, pustules, ulcers, and papillomatous proliferative lesions on the skin of the lips and nostrils. Here we describe a case of lethal cutaneous multifocal Orf virus infection in goats in the Amazon region of Brazil. Exanthematic lesions were collected and epidemiological and clinical data were obtained. Orf virus was detected using PCR amplification of the whole B2L, VIR, and VEGF open reading frame. Phylogenetic analysis revealed that this virus clustered together with the Orf virus samples isolated during classical contagious ecthyma. The present work is the first to report a severe proliferative Orf virus case in South America.

Liquid crystal colloidal structures for increased silicone deposition efficiency on colour-treated hair.

An approach is described to increase the deposition efficiency of silicone conditioning actives from a shampoo on colour-treated hair via liquid crystal (LC) colloidal structures, created with a high charge density cationic polymer, poly(diallyldimethyl ammonium chloride) and negatively charged surfactants. LCs are materials existing structurally between the solid crystalline and liquid phases, and several techniques, including polarized light microscopy, small angle X-Ray analysis, and differential scanning calorimetry, were used to confirm the presence of the LC structures in the shampoo formula. Silicone deposition from the LC-containing shampoo and a control shampoo was measured on a range of hair substrates, and data from inductively coupled plasma optical emission spectroscopy analysis and ToF-SIMS imaging illustrate the enhancement in silicone deposition for the LC shampoo on all hair types tested, with the most pronounced enhancement occurring on hair that had undergone oxidative treatments, such as colouring. A model is proposed in which the LC structure deposits from the shampoo onto the hair to: (i) provide 'slip planes' along the hair surface for wet conditioning purposes and (ii) form a hydrophobic layer which changes the surface energy of the fibres. This increase in hydrophobicity of the hair surface thereby increases the deposition efficiency of silicone conditioning ingredients. Zeta potential measurements, dynamic absorbency testing analysis and ToF-SIMS imaging were used to better understand the mechanisms of action. This approach to increasing silicone deposition is an improvement relative to conventional conditioning shampoos, especially for colour-treated hair.

Use of quaternized cassia galactomannan for hair conditioning.

There is a continuing need for hair care formulas to deliver superior conditioning benefits with highly efficient deposition of hair-enhancing components. In this paper, we describe high-charge-density (3.0 mEq/g) cassia hydroxypropyltrimonium chloride (cassia HPTC), a quaternized galactomannan from the endosperm of Cassia tora and Cassia obtusifolia. Cassia HPTC is shown to participate in the coacervate phase of conditioning shampoos, from which it is deposited onto hair to provide conditioning benefits. Cryo-scanning electron microscopy and time-of-flight secondary ion mass spectrometry were used to observe and characterize the cassia HPTC deposits left on hair. The high-charge-density cassia HPTC resulted in improved deposition efficiency compared with a quaternized guar-containing formula. Cassia HPTC offers benefits as an alternative to traditional cationic polymers as conditioning agents or as an adjunct conditioner to decrease the amount of cationic polymer needed to achieve the desired conditioning performance.

Molecular depth profiling of multilayer polymer films using time-of-flight secondary ion mass spectrometry.

The low penetration depth and high sputter rates obtained using polyatomic primary ions have facilitated their use for the molecular depth profiling of some spin-cast polymer films by secondary ion mass spectrometry (SIMS). In this study, dual-beam time-of-flight (TOF) SIMS (sputter ion, 5 keV SF(5)(+); analysis ion, 10 keV Ar(+)) was used to depth profile spin-cast multilayers of poly(methyl methacrylate) (PMMA), poly(2-hydroxyethyl methacrylate) (PHEMA), and trifluoroacetic anhydride-derivatized poly(2-hydroxyethyl methacrylate) (TFAA-PHEMA) on silicon substrates. Characteristic positive and negative secondary ions were monitored as a function of depth using SF(5)(+) primary ion doses necessary to sputter through the polymer layer and uncover the silicon substrate (>5 x10(14) ions/cm(2)). The sputter rates of the polymers in the multilayers were typically less than for corresponding single-layer films, and the order of the polymers in the multilayer affected the sputter rates of the polymers. Multilayer samples with PHEMA as the outermost layer resulted in lowered sputter rates for the underlying polymer layer due to increased ion-induced damage accumulation rates in PHEMA. Additionally, the presence of a PMMA or PHEMA overlayer significantly decreased the sputter rate of TFAA-PHEMA underlayers due to ion-induced damage accumulation in the overlayer. Typical interface widths between adjacent polymer layers were 10-15 nm for bilayer films and increased with depth to approximately 35 nm for the trilayer films. The increase in interface width and observations using optical microscopy showed the formation of sputter-induced surface roughness during the depth profiles of the trilayer polymer films. This study shows that polyatomic primary ions can be used for the molecular depth profiling of some multilayer polymer films and presents new opportunities for the analysis of thin organic films using TOF-SIMS.

Impact energy dependence of SF5+-induced damage in poly(methyl methacrylate) studied using time-of-flight secondary ion mass spectrometry.

Ion-induced damage of polymers is a critical factor in the depth profiling of polymer surfaces using polyatomic primary ions. In this study, time-of-flight secondary ion mass spectrometry was used to measure the damage of spin-cast poly(methyl methacrylate) (PMMA) films under 5-keV Cs(+) and 2.5-8.75-keV SF(5)(+) bombardment. Under 5-keV Cs(+) bombardment, the characteristic PMMA secondary ion intensities decreased rapidly for primary ion doses above 5 x 10(13) ions/cm(2). The damage profiles of PMMA under SF(5)(+) bombardment contained three distinct regions as a function of SF(5)(+) ion dose: a surface transient, an extended quasi-stabilization of the characteristic PMMA secondary ion intensities, and the decay of these intensities as the silicon substrate was reached. The PMMA film sputtered in a controlled manner for SF(5)(+) ion doses up to 4 x 10(14) ions/cm(2), with the maximum ion dose limited by the thickness of the PMMA film. Furthermore, the chemistry at the bottom of the sputter crater was significantly less modified by SF(5)(+) bombardment when compared with Cs(+) bombardment. The sputter rate was linearly correlated with the SF(5)(+) impact energy while the damage to the PMMA film varied minimally with the SF(5)(+) impact energy. These results were compared with Monte Carlo (SRIM) calculations of the penetration depth and vacancy production for SF(5)(+) at different impact energies. Since the SF(5)(+) impact energy only affected the sputter rate, selection of the appropriate SF(5)(+) impact energy for polymer depth profiling depends solely on the desired sputter rate.

Characterization of poly(L-lysine)-graft-poly(ethylene glycol) assembled monolayers on niobium pentoxide substrates using time-of-flight secondary ion mass spectrometry and multivariate analysis.

Control of protein adsorption onto solid surfaces is a critical area of biomaterials and biosensors research. Application of high performance surface analysis techniques to these problems can improve the rational design and understanding of coatings that control protein adsorption. We have used static time-of-flight secondary ion mass spectrometry (TOF-SIMS) to investigate several poly(L-lysine)-graft-poly(ethylene glycol) (PLL-g-PEG) adlayers adsorbed electrostatically onto negatively charged niobium pentoxide (Nb(2)O(5)) substrates. By varying the PEG graft ratio (i.e., the number of lysine monomers per grafted PEG chain) and the molecular weights of the PLL and PEG polymers, the amount of protein adsorption can be tailored between 1 and 300 ng/cm(2). Detailed multivariate analysis using principal component analysis (PCA) of the positive and negative ion TOF-SIMS spectra showed changes in the outermost surface of the polymer films that were related to the density and molecular weight of the PEG chains on the surface. However, no significant differences were noted due to PLL molecular weight, despite observed differences in the serum adsorption characteristics for adlayers of PLL-g-PEG polymers with different PLL molecular weights. From the PCA results, multivariate peak intensity ratios were developed that correlated with the thickness of the adlayer and the enrichment of the PEG chains and the methoxy terminus of the PEG chains at the outermost surface of the adlayer. Furthermore, partial least squares regression was used to correlate the TOF-SIMS spectra with the amount of protein adsorption, resulting in a predictive model for determining the amount of protein adsorption on the basis of the TOF-SIMS spectra. The accuracy of the prediction of the amount of serum adsorption depended on the molecular weight of the PLL and PEG polymers and the PEG graft ratio. The combination of multivariate analysis and static TOF-SIMS provides detailed information on the surface chemistry and insight into the mechanism for protein resistance of the coatings.

Hypothyroidism induces type 2 iodothyronine deiodinase expression in mouse heart and testis.

In the present study we show the expression profiles of both type 1 and type 2 iodothyronine deiodinases (D1 and D2) in a wide spectrum of mouse tIssues, and D2 regulation by thyroid status. A characteristic tIssue-specific expression for each isoform was observed. D2 transcripts were detected in most tIssues with variable levels of expression. The observed D2 mRNA tIssue distribution was similar to that described in rats and is in agreement with the view of different patterns of expression between rodents and humans. However, it is interesting to note that despite the low levels of D2 transcripts in mouse heart and testis in the euthyroid state, the induction of hypothyroidism caused a significant increase in D2 activity in these tIssues. Similar results were also obtained in adult rats. These results suggest a previously unrecognized role for type 2 deiodinase in controlling intracellular triiodothyronine levels in rodent heart and testis during states of thyroid hormone deficiency.

Quantitative analysis of binary adsorbed protein films by time of flight secondary ion mass spectrometry.

Time of flight secondary ion mass spectrometry (ToF-SIMS) is an ideal technique for the analysis of adsorbed protein films because of its surface sensitivity and chemical specificity. In this study, we examined ToF-SIMS with the multivariate calibration method partial least squares regression (PLSR) for the determination of the relative abundance of the components in binary protein films adsorbed onto mica, PTFE, and heptyl amine plasma polymer substrates. These results have been compared with independently measured 125I-radiolabeled protein adsorption experiments. By applying PLSR to the ToF-SIMS data, the relative abundance of the components in the binary adsorbed protein films was quantified, and the agreement between the ToF-SIMS and 125I-radiolabeling data was measured by the root mean square prediction error (RMSPE). Differences in protein quantification by PLSR and 125I-radiolabeling ranged from 5 to 25 mass % RMSPE and were highly dependent on the structure of the adsorbed protein film, the substrate surface chemistry and morphology, and the number of latent variables retained in the PLSR model. The limit of detection for the minor component in the adsorbed protein film was found to be approximately 10 mass %. This study demonstrates that the combination of ToF-SIMS and multivariate calibration provide complementary information to 125I-radiolabeling about the composition and structure of binary adsorbed protein films.

Characterizing multicomponent adsorbed protein films using electron spectroscopy for chemical analysis, time-of-flight secondary ion mass spectrometry, and radiolabeling: capabilities and limitations.

Characterization of complex adsorbed protein films is a critical aspect of biomaterials science, particularly in understanding the in vivo response to biomaterials. The surface analysis techniques electron spectroscopy for chemical analysis (ESCA) and time-of-flight secondary ion mass spectrometry (ToF-SIMS) are particularly suited to the analysis of complex adsorbed protein films due to their wide applicability to a variety of materials. We have investigated the applicability of ESCA for studying the structure of adsorbed serum and plasma protein layers. ESCA was able to monitor the thickness of the adsorbed protein film. Due to its chemical specificity, ToF-SIMS was used to estimate the composition of the plasma and serum protein layers by comparison of their spectra with the spectra of single protein films. The limit of detection of ToF-SIMS for the plasma protein fibrinogen was determined by comparison with independent radiolabeled fibrinogen adsorption measurements. While ToF-SIMS was able to determine some qualitative trends in the composition of the plasma protein films as a function of adsorption time, the detection limit of the minor components in multicomponent adsorbed protein films ultimately limits the ability of ToF-SIMS to quantify the composition of these films. However, both ESCA and ToF-SIMS can provide useful information on adsorbed plasma protein films without further sample treatment. This study outlines the strengths and weaknesses of ESCA and ToF-SIMS for studying multicomponent adsorbed plasma protein films.

Interpretation of static time-of-flight secondary ion mass spectra of adsorbed protein films by multivariate pattern recognition.

Multivariate analysis has become increasingly common in the analysis of multidimensional spectral data. We previously showed that the multivariate analysis technique principal component analysis (PCA) is an excellent method for interpreting the static time-of-flight secondary ion mass spectrometry (TOF-SIMS) spectra of adsorbed protein films. PCA is an unsupervised pattern recognition technique that loses resolution between spectra of different proteins as more proteins are added to the data set due to large within-group variation. The supervised pattern recognition techniques discriminant principal component analysis (DPCA) and linear discriminant analysis (LDA), which aim to control within-group variation while maximizing between-group separation to enhance discrimination between groups, were compared with PCA using data sets of TOF-SIMS spectra of proteins adsorbed onto mica and PTFE substrates. DPCA and LDA quantitatively improved discrimination between groups and provided different information about the data than PCA. LDA was able to classify unknown samples with a misclassification rate lower than PCA or DPCA. Both unsupervised and supervised pattern recognition techniques are useful for the interpretation and classification of static TOF-SIMS spectra of adsorbed protein films.

Characterization of adsorbed protein films by time of flight secondary ion mass spectrometry.

Time of flight secondary ion mass spectrometry (ToF-SIMS) is a useful technique in the study of adsorbed protein films because of its high surface sensitivity and chemical selectivity. However, the protein mass spectra generated by ToF-SIMS are complex fragmentation patterns of a polymer consisting of 20 different monomers (i.e., amino acids). Principal component analysis (PCA) was implemented to classify several reference positive ion protein spectra according to protein and substrate type. Furthermore, the positive ion 74/102 and 120/130 SIMS intensity ratios, radiolabeled experiments, and PCA were used to track the relative surface concentrations of bovine serum albumin and bovine fibronectin in a binary adsorption experiment. In all cases, the combination of ToF-SIMS and PCA proved capable in classifying proteins by their type (in the case of pure protein spectra) and relative surface concentration (in the case of the binary protein spectra).

Inhibition of monocyte adhesion and fibrinogen adsorption on glow discharge plasma deposited tetraethylene glycol dimethyl ether.

Monocytes and macrophages play important roles in host responses to implanted biomedical devices. Monocyte and macrophage interactions with biomaterial surfaces are thought to be mediated by adsorbed adhesive proteins such as fibrinogen and fibronectin. Non-fouling surfaces that minimize protein adsorption may therefore minimize monocyte adhesion, activation, and the foreign body response. Radio-frequency glow discharge plasma deposition (RF-GDPD) of tetraethylene glycol dimethyl ether (tetraglyme) was used to produce polyethylene oxide (PEO)-like coatings on a fluorinated ethylene-propylene (FEP) surface. Electron spectroscopy for chemical analysis (ESCA) and static time of flight secondary ion mass spectrometry (ToF-SIMS) were used to characterize the surface chemistry of tetraglyme coating. Fibrinogen adsorption to the tetraglyme surface was measured with 125I-labeled fibrinogen and ToF-SIMS. Adsorption of fibrinogen to plasma deposited tetraglyme was less than 10 ng cm(-2), a 20-fold decrease compared to untreated FEP or tissue culture polystyrene (TCPS). Monocyte adhesion to plasma deposited tetraglyme was significantly lower than adhesion to FEP or TCPS. In addition, when the surfaces were preadsorbed with fibrinogen, fibronectin, or blood plasma, monocyte adhesion to plasma deposited tetraglyme after 2 h or 1 day was much lower than adhesion to FEP. RF-GDPD tetraglyme coating provides a promising approach to make non-fouling biomaterials that can inhibit non-specific material-host interactions and reduce the foreign body response.

Study of V(1)-vascular vasopressin receptor gene microsatellite polymorphisms in human essential hypertension.

Vasopressin (AVP) actions on vascular tone and blood pressure are mainly mediated by the V(1)-vascular receptor (V(1)R). We recently reported the structure and functional expression of the human V(1)R cDNA and described the genomic characteristics, tissue expression, chromosomal localization, and regional mapping of the human V(1)R gene, AVPR1A. To test whether the V(1)R is a marker for human essential hypertension, we sequenced the human AVPR1A gene and its 5; upstream region and found several DNA microsatellite motifs. One (GT)(14)-(GA)(13)-(A)(8)microsatellite is located 2983 bp downstream of the transcription start site, within a 2.2 kbp intron interrupting the coding sequence of the receptor. Three other microsatellites are present in the 5; flanking DNA of the AVPR1A gene: a (GT)(25)dinucleotide repeat, a complex (CT)(4)-TT-(CT)(8)-(GT)(24)motif and a (GATA)(14)tetranucleotide repeat located respectively 3956 bp, 3625 bp and 553 bp upstream of the transcription start site. Analysis of these polymorphisms in 79 hypertensive and 86 normotensive subjects for the (GT)(14)-(GA)(13)-(A)(8)and the (GT)(25)motifs revealed a high percentage of heterozygosity but no difference in alleles frequencies between the two groups. A linkage study using the affected sib pair method and the (GT)(25)repeat in 446 hypertensive sib pairs from 282 French Caucasian pedigrees showed no excess of alleles sharing at the AVPR1A locus. No linkage was found in the subgroups of patients with early onset hypertension (diagnosis before age 40) or severe hypertension (diastolic blood pressure >/=100 mmHg or requirement for >/=two medications). These findings suggest that molecular variants of the V(1)R gene are not involved in unselected forms of essential hypertension.