Histoplasma capsulatum var. capsulatum within cutaneous nerves in patients with disseminated histoplasmosis and AIDS.
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AIDS-Related Opportunistic Infections↗
Biomedical subjects
A Motta
Publications and source records attributed to A Motta.
An expanded professional nursing role: increasing hospital reimbursement.
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Diagnosis-Related Groups↗
Poly(epsilon-caprolactone-co-D,L-lactide) /silk fibroin composite materials: preparation and characterization.
Poly(epsilon-caprolactone-co-D,L-lactide) copolymers with 10, 30, and 50% by weight of silk particles (size range: 5-250 microm) derived from Bombyx mori were blended in acetone solution. After evaporation of the solvent, the morphology, thermal behavior, and mechanical properties of the composites were examined. The composites were transparent and the silk fibroin particles were homogeneously distributed within the composite structure. The particles appeared as bright reflected images under the optical microscope, suggesting that they were in a crystalline state. DSC thermograms of the composites revealed that the glass transition of the matrix was at ca. -18 degrees C. Degradation of the silk fibroin occurred beyond 270 degrees C. The decomposition temperatures and degradation rate decreased with increasing silk fibroin content as revealed by TGA analysis. FTIR spectra of the composites showed absorption bands at 1730 and 1088 cm(-1) for the copolymer and at 3273 and 1617 cm(-1) for the silk fibroin. Although the characteristic lines of poly(epsilon-caprolactone-co-D,L-lactide) were independent of filler concentration. the absorption bands of the beta-sheet form of the silk fibroin increased slightly due to the interaction of silk fibroin with the copolymer.
Calorimetry↗
Distinguishing the drama from the histrionics in a case of hysteria with multiple tics.
The author describes a clinical experience with a hysterical patient with multiple tics, an upper-middle class, married woman, who when she started analysis at the age of 30 was in a state of profound tension and anxiety. The first eight years of this analysis are presented in order to describe how the analyst came to identify the dynamics of unconscious phantasies in a situation where analyst and patient found themselves involved in several roles of a drama dominated by theatrics. The insights and therapeutic benefits suggested that this patient unconsciously experienced her oral needs as intensely destructive and cruel, an experience she felt to have been exacerbated by her mother's lack of response to her emotional needs. This primitive cruel orality was accompanied by a split-off experience of a secret, mystical union with the primitive idealised mother. The author considers that this split experience of cruel and idealised orality suffused the patient's genital sexuality, hindering the evolution and realisation of her adult sexuality, giving her a distorted view of the primal scene as an impenetrable fused amalgam acting as an omnipotent, self-sufficient, excluding phallus. Gradually analysis enabled the patient to transform her bodily theatrics into thoughts and to broach the difficult task of relating to others instead of being either fused with them or totally excluded by them.
Adult↗
Trans-4-aminoproline, a phytotoxic metabolite with herbicidal activity produced by Ascochyta caulina.
A phytotoxic metabolite, characterized through NMR techniques and synthetic methods as trans-4-aminoproline, was isolated from the culture filtrates of Ascochyta caulina, a promising mycoherbicide for biological control of Chenopodium album. The metabolite, which shows interesting phytotoxic properties, together with ascaulitoxin (recently characterized as N.2-beta-D-glucoside of the unusual bis-amino acid 2,4,7-triamino-5-hydroxyoctandioc acid) and another unidentified compound, compose an active fraction of A. caulina culture filtrates with promising herbicidal properties. When assayed on leaves of host and non host dicots, including wild and cultivated plants, the trans-4-aminoproline showed a wide range of toxicity, with leaves of C. album being the most sensitive. Other interesting aspects were its inefficacy on several monocots, both cultivated and wild, and its lack of antifungal, antibiotic and zootoxic activities. This is the first report on trans-4-aminoproline as naturally occurring compound and phytotoxic metabolite produced by A. caulina.
Animals↗
Milk identification of different species: 13C-NMR spectroscopy of triacylglycerols from cows and buffaloes' milks.
Triacylglycerols from cows and buffaloes' milk fat were investigated by 13C nuclear magnetic resonance (NMR) spectroscopy. By the addition of pure triacylglycerols standards, we identified the resonances of both milk fats, and the peaks were used for qualitative and quantitative analysis of acyl groups. Multivariate analysis treatment of triacylglycerols distribution and composition parameters enabled us to identify milk. This study shows that NMR can safely be used to quantitate milk fatty acid content, providing unique information for milk identification of different animal species.
Animals↗
Prognostic significance of markers of thrombin generation in the acute and chronic phases of non cardioembolic ischemic stroke.
BACKGROUND: Previous studies have shown there is activation of the hemostatic system, with thrombin generation, in the acute phase of stroke. Such an activation has unfavourable effects. It is still not known whether there is also a persistent hypercoagulability state in these patients as well as in subjects affected by acute coronary syndromes. METHODS: To know more about the issue, we measured plasma levels of the prothrombin fragment 1 + 2 (F1 + 2) and the thrombin-antithrombin III complex (TAT) in 40 consecutive patients with first ischemic non-cardioembolic stroke; 16 matched involutive cardiomyopathy patients served as the control group. TATs and F1 + 2 were also assessed six months after the onset of stroke symptoms. RESULTS: At baseline stroke patients had higher values than controls of both F1 + 2 and TAT (F1 + 2: 2.38 +/- 2.30 nmol/l vs 1.20 +/- 0.50; p < 0.03; TAT 16.11 +/- 19.60 ng/ml vs 5.51 +/- 4.29; p < 0.05) and these measurements were not related to the typical acute phase reactants. After 6 months F1 + 2 levels in stroke patients were still higher than controls (F1 + 2: 1.68 +/- 0.80 nmol/l vs 1.20 +/- 0.50; p < 0.05), but there were no differences from the baseline levels of F1 + 2 and TAT. According to survival curves mortality was significantly higher in patients with hypercoagulability (defined as F:1 + 2 and TAT levels more than two standard deviations above the mean). CONCLUSIONS: These data confirm that for stroke patients there is sustained activation of the blood coagulation system like in unstable angina and myocardial infarction these abnormalites may have unfavourable prognostic significance.
Acute Disease↗
In vitro evaluation of the inflammatory potential of the silk fibroin.
Silk fibroin membranes recently have been suggested as matrices for biomedical applications, such as guided tissue regeneration and burn wound dressings. The aim of this study was to evaluate the inflammatory potential of fibroin films and to compare the fibroin films with two model materials with completely different physico-chemical properties: poly(styrene) and poly(2-hydroxyethyl methacrylate). Fibroin bound lower levels of fibrinogen than did the two synthetic polymers while the same amounts of adsorbed human plasma complement fragment C3 and IgG were detected. Studies of the binding strength of C3 to fibroin, evaluated by a novel experimental procedure, indicated the occurrence of strong hydrophobic interactions at the interface. The activation of the mononuclear cells by fibroin, measured as interleukin 1beta production, was lower than the reference materials. Adhesion experiments showed the ability of the macrophages to adhere to fibroin by filopodia without a complete spreading of the cells. The results achieved in this study demonstrate that the interactions of fibroin with the humoral components of the inflammatory system were comparable with those of the two model surfaces while the degree of activation and adhesion of the immunocompetent cells appeared more limited.
Adsorption↗
Synergistic effects of oxidative environments and mechanical stress on in vitro stability of polyetherurethanes and polycarbonateurethanes.
The in vitro structural stability of polyetherurethanes (PEUs) and polycarbonateurethanes (PCUs and PCUUs) was examined under strong oxidative conditions (0.5N HNO3, pH 0.3; and NaClO, 4% Cl2 available, pH approximately 13) and in the presence of a constant strain state. Solvent-cast dog-bone shaped specimens were strained at 100% uniaxial elongation over extension devices and completely immersed in the oxidative solutions at 50 degrees C for 15 days. Unstrained polyurethane (PU) samples were treated in the same way for comparison. The modification of the PU molecular structure was determined by DSC, GPC, ATR-FTIR, static contact angle, and surface roughness analyses. The incubation in nitric acid and sodium hypochlorite brought about a greater degradation of samples tested under the applied strain with the exception of PEU treated with nitric acid. PEU was the most affected material, showing bulk deterioration in NaClO and significant modifications in nitric acid, with the appearance of new IR bands, which were assigned to oxidation products. A higher phase separation between soft and hard domains occurred in PCUs upon incubation in nitric acid, the treatment with NaClO gave rise to new bands in the IR spectra, denoting the presence of oxidation products at the surface. The surface roughness greatly increased in strained PCUs with SEM evidence of deep cracks and holes or ragged and stretched fractures perpendicular to the direction of stress. PCUU underwent complex chemical modifications with a marked decrease of N-H and urea IR absorptions and showed a lower degradation than PEU and PCUs under mechanical constraint. From these results, sodium hypochlorite appears to be able to create an ESC-like degradation for PUs that are resistant to other aggressive chemical environments.
Microscopy, Electron, Scanning↗
Forced adhesive growth of K562 leukemic cells that normally grow in suspension induces variations in membrane lipids and energy metabolism: a proton NMR study.
The mechanisms responsible for the adhesion of cells onto a material's surface and the effects that that adhesion may have on cell structure and function are fundamental questions in biomaterials research. We recently demonstrated that the erythroleukemic cell line K562, which normally grows in suspension, can be induced to grow attached to a polylysine-coated solid surface in an anchorage-dependent manner. In this study, the effects of the growth of K562 cells onto polylysine were further investigated utilizing 500 MHz 1H-NMR spectroscopy. The NMR results showed that when K562 cells are grown attached to a positively-charged polylysine surface, there are alterations in lipids and energy metabolism. In particular, there was a 31% increase in phosphatidylcholine and a 15% decrease in each of its two precursors, glycerophosphatidylcholine and choline, as well as a 20% increase in CH2 lipids and a 7% decrease in CH3 lipids in treated cells compared to the controls. These results suggest that adhesive growth can induce strong variations in membrane structure, including the membrane fluidity of K562 cells. In addition, in cells attached to polylysine there was about a 10% decrease in creatine (together with phosphocreatine), a 20% increase in gamma-glutamate, a 15% increase in beta-glutamate, and a 24% decrease in lactate. This second set of results, which is closely related to energy metabolism, indicates that not only does adhesive growth induce changes in K562 cell membrane structure, but also in the utilization of energy in these cells. The data are discussed in view of the possible role played by surface charge in affecting cell structure and function in cells that come into direct contact with charged biopolymers.
Cell Adhesion↗
Effect of the urine conditioning film on ureteral stent encrustation and characterization of its protein composition.
The goal of this study was to characterize the protein composition of the conditioning film deposited onto the surface of ureteral stents during in vivo implantation and to relate its presence to the precipitation of calcium crystals. The protein pattern of the conditioning film of implanted nonencrusted and encrusted urological stents was assessed by SDS-PAGE and Western blot of the desorbed species. The results obtained highlighted different electrophoresis profiles between nonencrusted and encrusted stents. Western blot showed the ubiquitous presence of albumin, while Tamm-Horsfall Protein and alpha1-microglobulin adsorption was limited to nonencrusted devices. By an in vitro dynamic model in which artificial urine was flowed through the lumen of control and retrieved nonencrusted stents, we demonstrated that the organic layer remarkably enhanced crystal precipitation and aggregation events on the surface.
Adsorption↗
Interactions of anthracyclines with zwitterionic phospholipid monolayers at the air-water interface.
The present note describes the use of surface pressure measurements (Langmuir monolayer technique) for the analysis of interactions of two different anthracyclines (adriamycin and daunorubicin) with a non-ionic, zwitterionic phospholipid monolayer, at the air-water interface. Because the surface membrane of the cell is the first barrier encountered by the anthracyclines in the treatment of cancer, drug-membrane interactions studied in model (monolayers or bilayers) and natural systems play an important role in the understanding of the bioactivity properties of these molecules. We report here the rate constants of the adsorption process of adriamycin and daunorubicin in the presence of a zwitterionic phospholipid monolayer at the air-water interface. Because interactions with the lipid monolayer strongly depend on the molecular packing of the lipid, we investigated this process at a relatively low surface pressure (7 mN/m), the interactions being favoured by the gaseous and liquid expanded structure of the lipid monolayer. The apparent molecular area of these molecules during the insertion into the lipid film and their interactions with the phospholipid polar head groups was evaluated and the estimated percentage of anthracyclines at the interface after adsorption into the lipid monolayer is briefly discussed. The rate constants for the adsorption and desorption process at the water-monolayer interface have been calculated on the basis of a single-exponential model. The observed difference of these parameters for daunorubicin and adriamycin suggests a different interaction of these anthracyclines during the adsorption to and/or penetration across the phospholipid monolayer.
Air↗
Iopiperidol: nonionic iodinated contrast medium with promising anticoagulant and antiplatelet properties.
RATIONALE AND OBJECTIVES: The purpose of this study was to determine the anticoagulant and antiplatelet characteristics of iopiperidol, a nonionic, triiodinated contrast agent. MATERIALS AND METHODS: Anticoagulant effects of iopiperidol were assessed both in vitro and in vivo after single or repeated intravenous administrations to rats. To this aim, results of prothrombin time, activated partial thromboplastin time, thrombin time, and fibrinogen tests were evaluated. To define better the mechanism of action of iopiperidol and of the contrast media used for comparison, in vitro tests to study the effects on thrombin activity and on thrombin generation were performed. In addition, the effect of iopiperidol was studied on adenosine diphosphate- and collagen-induced platelet aggregation both in vitro and in vivo after single or repeated intravenous administrations in the rat. RESULTS: In vitro, iopiperidol showed anticoagulant properties similar or superior to those of the ionic ioxaglate. Iopiperidol also inhibited collagen-induced platelet aggregation statistically significantly more than iodixanol and ioxaglate (P < .05). In vivo, no significant differences between iopiperidol and ioxaglate were observed after single or repeated administrations. CONCLUSION: The in vitro anticoagulant effect of iopiperidol is similar or even superior to that of ioxaglate; the in vivo effect is similar to that of reference nonionic contrast media.
Animals↗
Sapinofuranones A and B, two new 2(3H)-dihydrofuranones produced by sphaeropsis sapinea, a common pathogen of conifers
Two new 5-substituted dihydrofuranones, named sapinofuranones A and B (1 and 2), were isolated from liquid cultures of Sphaeropsis sapinea, a phytopathogenic fungus causing a wide range of disease symptoms on conifers. A fungal strain isolated from Cupressus macrocarpa produced both 1 and 2 at concentrations higher than those produced by the strain isolated from Cupressus sempervirens. Bioassay of 1 and 2 gave epinasty and brown discoloration on petioles of tomato leaves, sapwood stain on inner cortical tissues of the stem of cypress seedlings, and yellowing and needle blight on pine seedlings. Compounds 1 and 2 were characterized, using spectroscopic and chemical methods, as two new 4-[(2Z, 4E)-1-hydroxy-2,4-hexadienyl]butan-4-olides, which are epimers at C-1 of the side chain. The absolute stereochemistry of this chiral center, determined by application of the Mosher's method, proved to be S and R in 1 and 2, respectively.
Journal Article↗
Conformational flexibility in calcitonin: the dynamic properties of human and salmon calcitonin in solution.
We have studied the dynamic properties of human (h) and salmon (s) calcitonin (CT) in solution. For both hormones, distance geometry in torsion-angle space has been used to generate three-dimensional structures consistent with NMR data obtained in sodium dodecyl sulfate micelles. For sCT and hCT we used, respectively, 356 and 275 interproton distances together with hydrogen-bonds as restraints. To better characterize their flexibility and dynamic properties two fully unrestrained 1100-ps molecular dynamics (MD) simulations in methanol were performed on the lowest-energy structures of both hormones. Statistical analyses of average geometric parameters and of their fluctuations performed in the last 1000 ps of the MD run show typical helical values for residues 9-19 of sCT during the whole trajectory. For hCT a shorter helix was observed involving residues 13-21, with a constant helical region in the range 13-19. Angular order parameters S(phi) and S(psi) indicate that hCT exhibits a higher flexibility, distributed along the whole chain, including the helix, while the only flexible amino acid residues in sCT connect three well-defined domains. Finally, our study shows that simulated annealing in torsion-angle space can efficiently be extended to NMR-based three-dimensional structure calculations of helical polypeptides. Furthermore, provided that a sufficient number of NMR restraints describes the system, the method allows the detection of equilibria in solution. This identification occurs through the generation of 'spurious' high-energy structures, which, for right-handed alpha-helices, are likely to be represented by left-handed alpha-helices.
Amino Acid Sequence↗
Low chronic ethanol consumption affects ovulation and PGE synthesis by the cumulus cell masses in mice.
Central and gonadal function can be affected by chronic consumption of high and moderate doses of ethanol. Few studies have been conducted to determine the effect of ethanol intake at ovarian and gamete level. Previously, we showed that fertilization rates of low chronic ethanol treated female mice were diminished. Also, our recent results indicated that moderate chronic intake of ethanol by immature females could alter the ovulatory quantity and produce morphological alterations in the superovulated oocytes. Furthermore, PGE production by oocyte cumulus complexes (OCCs) was reduced in the females treated with 10% (w/v) ethanol. In the present investigation, we studied the effects of 5% ethanol treatment given to immature mice for 30 days on the quality and quantity of oocytes superovulated at 16 h posthuman chronic gonadotrophin. Treated females had impaired ovulation rates (P < 0.05) as compared to the controls. The percentage of activated and morphologically abnormal oocytes was elevated in the ethanol-treated females (P < 0.05). PGE synthesis by the OCCs was higher than in the controls (P < 0.01). In summary, the administration of long-term ethanol at a relatively low dose to immature females produces decreased ovulation rates, abnormal oocyte morphology with high spontaneous activation and altered levels of PGE production by the oocytes' cumulus complexes. The relationship between the oocyte quality and abnormal synthesis of PGE is discussed.
Animals↗
Progesterone enhances prostaglandin E2 production via interaction with nitric oxide in the mouse acrosome reaction.
In the present study we evidenced that progesterone could directly stimulate sperm nitric oxide synthase (NOS) in capacitated mouse spermatozoa. This stimulation led to an increase in sperm prostaglandin E2 (PGE2) production and subsequent acrosomal exocytosis. However, cGMP levels were not modified during the progesterone-induced acrosome reaction under our experimental conditions. These results suggest a functional role for nitric oxide as an intracellular messenger through, at least, stimulation of PGE2 production during the acrosome reaction triggered by progesterone.
Acrosome Reaction↗
Solution structure of human calcitonin in membrane-mimetic environment: the role of the amphipathic helix.
The 32 amino acid hormone human calcitonin was studied at pH 3.7 and 7.4 by multidimensional NMR spectroscopy in sodium dodecyl sulfate micelles at 310K. The secondary structure was obtained from nuclear Overhauser enhancement spectroscopy (NOESY), 3JHNalpha coupling constants, and slowly exchanging amide data. Three-dimensional structures consistent with NMR data were generated by using distance geometry calculations. A set of 265 interproton distances derived from NOESY experiments, hydrogen-bond constraints obtained from amide exchange, and coupling constants were used. From the initial random conformations, 30 distance geometry structures with minimal violations were selected for further refinement with restrained energy minimization. In micelles, at both pHs, the hormone assumes an amphipathic alpha-helix from Leu9 to Phel6, followed by a type-I beta-turn between residues Phel6 and Phel9. From His20 onward the molecule is extended and no interaction with the helix was observed. The relevance of the amphipathic helix for the structure-activity relationship, the possible mechanisms of interaction with the receptor, as well as the formation of fibrillar aggregates, is discussed.
Amino Acid Sequence↗