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Biomedical subjects

R Cruz

Publications and source records attributed to R Cruz.

At least 19 recordsLinked to original sources
PubMed2001

Immunohistochemical localization and electrophysiological action of nociceptin/orphanin-FQ in the snail (Helix aspersa) neurons.

We report the existence and anatomical distribution to nociceptin/orphanin-FQ (N/O FQ)-like immunoreactivity in neurons and fibers in the perioesophageal ganglia of the snail (Helix aspersa). Intracellular recordings from perioesophageal ganglion neurons showed that the application of 10 microM N/O FQ produced an excitatory action in 22% of the neurons studied and an inhibitory action in 33% of the neurons regardless of their origin (cerebral or parietal ganglion). Our result provides evidence that N/O FQ-like peptide is located in whole perioesophageal ganglia (mainly in the cerebral one), and that it may serve as a neuromodulator of the neuronal spike discharge. These data support the idea that the N/O FQ opioid system has an early phylogenetic origin and a functional continuity during the course of evolution.

Action Potentials↗
PubMed2001

Increases in fines and driver licence withdrawal have effectively reduced immediate deaths from trauma on Brazilian roads: first-year report on the new traffic code.

Road accidents are a major cause of death in Brazil, with rates increasing steadily for years. Our objective here is to report the impact of the new Brazilian Traffic Code, introduced in 1998. Its main new features include a large increase in fines and a rigid penalty scoring system that leads to driver license withdrawal. Speed limits have actually been raised on many roads, but adherence to the rules has been monitored more closely. We compare the incidence of injured patients and immediate deaths in road accidents and emergency room admissions to a level I trauma centre in downtown São Paulo between January and December 1998 with corresponding data from between January and December 1997. There was an overall 21.3% reduction in the number of accidents and a 24.7% reduction in immediate deaths, saving 5962 lives on Brazilian highways. Tickets issued fell by 49.5% (601977 during 1997 to 304785 during 1998). Motor vehicle accident-related emergency room admissions decreased by 33.2%. We conclude that very costly tickets and threatened driver licences have proved very effective in decreasing immediate deaths from trauma. Further advances in educational programmes associated with road and vehicle safety measures are likely to provide the much needed further reduction in the still high trauma mortality on Brazilian roads and streets.

Accidents, Traffic↗
PubMed2000

Genome sequence of Halobacterium species NRC-1.

We report the complete sequence of an extreme halophile, Halobacterium sp. NRC-1, harboring a dynamic 2,571,010-bp genome containing 91 insertion sequences representing 12 families and organized into a large chromosome and 2 related minichromosomes. The Halobacterium NRC-1 genome codes for 2,630 predicted proteins, 36% of which are unrelated to any previously reported. Analysis of the genome sequence shows the presence of pathways for uptake and utilization of amino acids, active sodium-proton antiporter and potassium uptake systems, sophisticated photosensory and signal transduction pathways, and DNA replication, transcription, and translation systems resembling more complex eukaryotic organisms. Whole proteome comparisons show the definite archaeal nature of this halophile with additional similarities to the Gram-positive Bacillus subtilis and other bacteria. The ease of culturing Halobacterium and the availability of methods for its genetic manipulation in the laboratory, including construction of gene knockouts and replacements, indicate this halophile can serve as an excellent model system among the archaea.

Biological Evolution↗
PubMed2000

Least-effort pathways?: a GIS analysis of livestock trails in rugged terrain.

Livestock trails frequently evolve in pastures when plant growth or establishment cannot keep pace with vegetation disturbance. In some instances, man-made trails are established in rangeland settings to encourage uniform use of forages or facilitate livestock passage through dense vegetation or across rugged terrain. A long-term assumption has been that livestock establish pathways of least resistance between frequented areas of their pastures, but this hypothesis has never been tested. We mapped cattle trails in three 800+ ha pastures with global positioning units. A geographic information system (GIS) helped quantify characteristics of trails and the landscape and was used to plot least-effort pathways between water sources and distant points on selected trails in the pastures. Characteristics of the cattle trails and least-effort pathways were compared to test the hypothesis that cattle develop least-effort routes of travel in rugged terrain. The mean slope of the three pastures was 13.5%, and the average slope of the topography traversed by the cattle trails was 8%. The slope of the trails was reduced to 5.2% by selection of cross-slope routes. When we compared the characteristics of 10 selected cattle trails and least-effort pathways generated by our GIS, the cattle trails were 11% shorter (P=0.046) than the least-effort pathways, and the topography traversed by cattle had a gradient about 1% less than the least-effort pathways (P=0.02). The slope of the selected trails (5.5%) and pathways (5.6%) were similar (P=0.74), however. Analyses of values extracted from cost surfaces indicated that, on the average, 183 units of effort were needed to traverse the trails and 170 units of effort expended to traverse the least-effort pathways (P=0.07). These data support the hypothesis that cattle establish least-effort routes between distant points in rugged terrain and suggest that GIS software may be useful in designing systems of livestock trails in extensive settings.

Journal Article↗
PubMed2000

Preparation and characterization of Furosemide-Eudragit controlled release systems.

Solid dispersions and physical mixtures were prepared and characterized by X-ray diffraction, infrared spectroscopy, electronic microscopy and dissolution rate studies. The characterization with X-ray diffraction showed a transition from the crystalline to the amorphous phase. A new phase near 50% Furosemide concentration with both types of carriers was present. From infrared spectroscopy strong interactions between amine and carbonyl groups from both the Furosemide and the polymers were found. Electronic microscopy analysis showed that the Furosemide changed its crystalline habit from needle to a new spherical phase, with diameter near to 1 microm. Solid dispersions were prepared in order to modify the system characteristics. The Furosemide dissolution rate was determined in order to follow the behavioural changes of the system. Scanning electron microscopy showed the presence of micro spheres within the polymeric matrix, and the channels formed due to the Furosemide dissolution inside the Eudragit: this fact modified the release pattern of the Furosemide system.

Acrylic Resins↗
PubMed2000

APHE-3, a spore-associated antibiotic of Streptomyces griseocarneus NCIMB 40447.

Solid cultures of the producing strain grown on Bennett medium develop abundant mycelium and intense sporulation. Under these conditions biosynthesis of APHE antibiotics (APHE-1 to -3) is accomplished. Further studies show that APHE-3 is basically produced during spore formation and mostly present in spores, while APHE-1 and APHE-2 are the predominant antibiotics in the mycelium. APHE compounds are present in almost all streptomycetes tested, indicating a possible role in the life cycle of these microorganisms.

Chromatography, High Pressure Liquid↗
PubMed2000

Microcomputer program for automated action potential waveform analysis.

A program for action potential waveform analysis based on a PC compatible computer is described. Single or averaged action potentials are analyzed by obtaining its first derivative and using criteria which allow automatic measurement of several action potential components, including: depolarization rate, repolarization rate, amplitude, duration, resting membrane potential and afterhyperpolarization amplitude and slope. Data can be imported from pClamp (Axon Instruments) and exported to other software such as Excel, Sigmaplot and MatLab for example.

Action Potentials↗
PubMed2000

Synthesis and experimental study of through-space hydrogen-fluorine and carbon-fluorine spin-spin coupling in 4,5-substituted 1-acetyl-8-fluoronaphthalenes.

The synthesis and NMR study (1H, 13C, and 19F) of a complete series of 4,5-substituted 1-acetyl-8-fluoronaphthalenes are reported. This data revealed a 6J(H,F) and a 5J(C,F) through space coupling between the fluorine and the methyl on the acetyl group (1H and 13C). The magnitude of this coupling constant changes depending on the nature of the substituent at C-4, the internuclear distance, and the solvent.

Carbon↗
PubMed2000

Methyl jasmonate reduces chilling injury and maintains postharvest quality of mango fruit.

Exposure of mango (Mangifera indica cv. Tommy Atkins) fruit to methyl jasmonate (MJ) vapors (10(-)(4) M) for 24 h at 25 degrees C reduced chilling injury during subsequent storage for 21 days at 7 degrees C and after 5 days of shelf life at 20 degrees C. The chilling tolerance induced by MJ was positively correlated with the reduction in the percent ion leakage of mango tissue. The overall quality of MJ-treated fruit was also better than that of control fruit. MJ treatment increased the total soluble solids but did not affect titratable acidity or pH. MJ also did not change the normal climacteric rise in respiration, water loss, and softening rates. The efficacy of MJ to reduce chilling injury and decay of mango could be related to the tolerance induced at low temperature. It was concluded that MJ treatment may prevent chilling injury symptoms of mango without altering the ripening process.

Acetates↗
PubMed2000

The efficacy of ECT in mixed affective states.

ECT is efficacious in the treatment of both the depressed and manic phases of bipolar disorder. While ECT is believed to be equally efficacious in the treatment of mixed affective states, to our knowledge there are no empirical studies on this issue. A chart review study was conducted to compare treatment response and clinical course in three groups of patients who received ECT in a general hospital service: bipolar depressed (n = 38), bipolar manic (n = 5), and bipolar mixed (n = 10), diagnosed by DSM-IV criteria. All three groups showed robust response rates, but the number of days of hospitalization was significantly longer in the mixed group (mean 30, SD 19.0 days) compared with the depressed group (mean 19.0, SD 10.9 days, t = 2.4, p < 0.03). There was a trend for the number of ECT treatments to be greater in the mixed compared with the depressed group. These findings indicate that patients with mixed affective states do respond well to a course of ECT, but the longer hospital stays and greater number of ECT treatments suggest that they may be more difficult to treat with ECT than patients with pure bipolar depression or bipolar mania.

Adult↗
PubMed2000

Multi-center clinical comparison of combination anorganic bovine-derived hydroxyapatite matrix (ABM)/cell binding peptide (P-15) and ABM in human periodontal osseous defects. 6-month results.

BACKGROUND: Intraosseous periodontal defects present a particular treatment problem. New bone replacement grafts offer promise for improved results. METHODS: The role of a synthetic cell-binding peptide (P-15), combined with anorganic [corrected] bovine-derived hydroxyapatite bone matrix (ABM), was compared to ABM alone in human periodontal osseous defects in a controlled, monitored, multi-center trial. Following appropriate initial preparation procedures, flap surgery with defect and root debridement was performed. Two osseous defects per patient were treated randomly with each procedure after surgical preparation. Appropriate periodontal maintenance schedules were followed, and at 6 to 7 months, re-entry flap surgery was performed for documentation and finalization of treatment. RESULTS: T test and Mann-Whitney U analyses of patient mean values from 33 patients revealed that the combination ABM/P-15 grafts demonstrated significantly better mean defect fill of 2.9 +/- 1.2 mm (72.9%) versus a mean defect fill of 2.2 +/- 1.4 mm (50.67%) for defects treated with ABM (P<0.05). Other hard tissue findings showed similar clinically superior results with the use of ABM/P-15. Relative defect fill results showed 81% positive (50% to 100% defect fill) responses with ABM/P-15 and 67% positive responses with ABM. There were 3.5 times as many optimal results (> or = 90% defect fill) with ABM/P-15 and twice as many failures (minimal response) with ABM. Soft tissue findings showed no significant differences between treatments. CONCLUSIONS: These results suggest that the use of the P-15 synthetic cell-binding peptide combined with ABM yields better clinical results than the ABM alone in intrabony periodontal defects.

Adult↗
PubMed2000

[Cervical spondylodiscitis in an infant].

Spondylitis in childhood is rare, presenting a great variety of symptoms that are related to the child s age and to the site of the inflammatory process. We present the case of a nine-month-old infant, who presented to the emergency department with a torticollis of six weeks evolution. The diagnosis of spondylitis (C6-C7) was confirmed by MRI. Intravenous antibiotic therapy was administered. The patient showed complete regression of symptoms and imaging tests were normal. The rarity of this disease in patients in this age group, as well as the site and form of presentation are emphasised as is the importance of diagnosing this disease to prevent permanent neurological injuries or bone deformities.

Cervical Vertebrae↗
PubMed1999

Does serum ferritin correlate with coronary angiography findings?

BACKGROUND: A number of epidemiological studies have described a positive relationship between serum ferritin levels and coronary heart disease. In this prospective study, we evaluated the association between serum ferritin levels and the angiographic extent of coronary atherosclerosis. METHOD: We studied 307 consecutive patients (60.9% male, age 60.1+/-11.0 years) referred for diagnostic coronary angiography. Risk factors for coronary artery disease, lipids and ferritin levels, as well clinical characteristics were recorded from all patients. Two experienced cardiologists blinded for clinical and laboratory data reviewed the cinefilms. Angiographic significant coronary artery disease (CAD) was defined as any more than a 50% diameter stenosis. RESULTS: From the 307 patients, 196 (63.8%) were found to have angiographic significant CAD. The presence of significant CAD was associated with ferritin levels (P=0.015) as well as patient age (P<0.001), male sex (P<0.001), smoking (P<0.002), and cholesterol levels (P=0.028). By multivariate analysis, however, ferritin level was not an independent risk factor for CAD (P=0.27), while the association with all the other factors remained significant. CONCLUSION: In patients referred for coronary angiography no independent relationship was found between angiographic significant coronary artery disease and serum ferritin levels.

Analysis of Variance↗
PubMed1999

Frequency of perseveration in normal subjects.

Although perseveration is a recognized sign of disturbed brain function, it also occurs in normal individuals. Determination of the frequency of perseveration in normal subjects would enable clinicians to use perseveration as a marker of possible pathology. The purpose of this study was to document the extent of perseveration in normal young and older subjects. Thirty young normal individuals between the ages of 20 and 35 years and 30 older normal individuals between the ages of 60 and 75 years were given four tasks on which perseveration has been reported in brain-damaged individuals. Four percent of all responses were perseverative. No age or gender effects on frequency were observed. Of the four neuropsychological tasks, the Modified Wisconsin Card Sorting Test elicited the greatest number of perseverations.

Adult↗
PubMed1999

Atomic force microscopy study of tooth surfaces.

Atomic force microscopy (AFM) was used to study tooth surfaces in order to compare the pattern of particle distribution in the outermost layer of the tooth surfaces. Human teeth and teeth from a rodent (Golden hamster), from a fish (piranha), and from a grazing mollusk (chiton) with distinct feeding habits were analyzed in terms of particle arrangement, packing, and size distribution. Scanning electron microscopy and transmission electron microscopy were used for comparison. It was found that AFM gives high-contrast, high-resolution images and is an important tool as a source of complementary and/or new structural information. All teeth were cleaned and some were etched with acidic solutions before analysis. It was observed that human enamel (permanent teeth) presents particles tightly packed in the outer surface, whereas enamel from the hamster (continuously growing teeth) shows particles of less dense packing. The piranha teeth have a thin cuticle covering the long apatite crystals of the underlying enameloid. This cuticle has a rough surface of particles that have a globular appearance after the brief acidic treatment. The similar appearance of the in vivo naturally etched tooth surface suggests that the pattern of globule distribution may be due to the presence of an organic material. Elemental analysis of this cuticle indicated that calcium, phosphorus, and iron are the main components of the structure while electron microdiffraction of pulverized cuticle particles showed a pattern consistent with hydroxyapatite. The chiton mineralized tooth cusp had a smooth surface in an unabraded region and a very rough structure with the magnetite crystals (already known to make part of the structure) protruding from the surface. It was concluded that the structures analyzed are optimized for efficiency in feeding mechanism and life span of the teeth.

Acids↗
PubMed1999

Letter

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Journal Article↗