Showing papers by "University of São Paulo published in 1999"

Reference values for lung function tests. II. Maximal respiratory pressures and voluntary ventilation

Abstract: The strength of the respiratory muscles can be evaluated from static measurements (maximal inspiratory and expiratory pressures, MIP and MEP) or inferred from dynamic maneuvers (maximal voluntary ventilation, MVV). Although these data could be suitable for a number of clinical and research applications, no previous studies have provided reference values for such tests using a healthy, randomly selected sample of the adult Brazilian population. With this main purpose, we prospectively evaluated 100 non-smoking subjects (50 males and 50 females), 20 to 80 years old, selected from more than 8,000 individuals. Gender-specific linear prediction equations for MIP, MEP and MVV were developed by multiple regression analysis: age and, secondarily, anthropometric measurements explained up to 56% of the variability of the dependent variables. The most cited previous studies using either Caucasian or non-Caucasian samples systematically underestimated the observed values of MIP (P < 0.05). Interestingly, the self-reported level of regular physical activity and maximum aerobic power correlates strongly with both respiratory and peripheral muscular strength (knee extensor peak torque) (P < 0.01). Our results, therefore, provide a new frame of reference to evaluate the normalcy of some useful indexes of respiratory muscle strength in Brazilian males and females aged 20 to 80.

Extensive 200-Million-Year-Old Continental Flood Basalts of the Central Atlantic Magmatic Province

Abstract: The Central Atlantic Magmatic Province (CAMP) is defined by tholeiitic basalts that crop out in once-contiguous parts of North America, Europe, Africa, and South America and is associated with the breakup of Pangea. 40Ar/39Ar and paleomagnetic data indicate that CAMP magmatism extended over an area of 2.5 million square kilometers in north and central Brazil, and the total aerial extent of the magmatism exceeded 7 million square kilometers in a few million years, with peak activity at 200 million years ago. The magmatism coincided closely in time with a major mass extinction at the Triassic-Jurassic boundary.

Experiments and theory in cold and ultracold collisions

Abstract: The authors review progress in understanding the nature of atomic collisions occurring at temperatures ranging from the millidegrees Kelvin to the nanodegrees Kelvin regime. The review includes advances in experiments with atom beams, light traps, and purely magnetic traps. Semiclassical and fully quantal theories are described and their appropriate applicability assessed. The review divides the subject into two principal categories: collisions in the presence of one or more light fields and ground-state collisions in the dark.

Worldwide large-scale fluctuations of sardine and anchovy populations

Abstract: Decade-scale regimes of sardine Sardinops sagax and anchovy Engraulis spp. have been observed in the productive coastal waters of the North-Western, North-Eastern and South-Eastern Pacific and the South-Eastern Atlantic. In each of these systems, the two genera fluctuate out of phase with each other. The subdominant genus may initiate a recovery while the other species is still abundant, so population growth is not necessarily a response to a vacant niche. Rather, it appears to be triggered by formation of one or a few powerful year-classes. At high population levels, quality of sardine and their eggs decreased in Japan, leading to decreased production and survival of eggs, poor year-classes and stock collapse. Excessive fishing of strong year-classes early in the recovery stage may prevent a species from assuming dominance, so influencing the natural succession of species. This may greatly alter the structure and functioning of an ecosystem. For example, a mesopelagic forage fish may replace an epipelagi...

The microtensile bond test: a review.

Abstract: Purpose: The purpose of this review is to describe ail of the various modifications of the microtensile bond test in one paper, so that investigators can select the modification that best suits their needs. Methods: The essence of the microtensile test is the division of resin-bonded teeth into siabs between 0.5 and 1.0 mm thick that are then trimmed in such a manner that tensile force will be concentrated on the bonded interface during testing. Among the many advantages of the technique are that each tooth produces multiple specimens. Further, there is no need for a matrix to limit the bonded surface area, since the area is determined by the dimensions of the trimmed specimens. Results: The various modifications of the microtensile test have been used to measure differences in regional bond strength across occiusal dentin, down the external surface of teeth from crown through roots, down the internal surface of root oanals from cervical to apical thirds, as well as tc ccmpare normal vs caries-affected occiusai dentin and normal vs sclerotic cervical dentin. The technique is ideal for evaiuating the long-term durauiiity of resin-hard-tissue bonds.

Therapy of tuberculosis in mice by DNA vaccination.

Abstract: Mycobacterium tuberculosis continues to kill about 3 million people every year, more than any other single infectious agent This is attributed primarily to an inadequate immune response towards infecting bacteria, which suffer growth inhibition rather than death and subsequently multiply catastrophically Although the bacillus Calmette-Guerin (BCG) vaccine is widely used, it has major limitations as a preventative measure In addition, effective treatment requires that patients take large doses of antibacterial drug combinations for at least 6 months after diagnosis, which is difficult to achieve in many parts of the world and is further restricted by the emergence of multidrug-resistant strains of M tuberculosis In these circumstances, immunotherapy to boost the efficiency of the immune system in infected patients could be a valuable adjunct to antibacterial chemotherapy Here we show in mice that DNA vaccines, initially designed to prevent infection, can also have a pronounced therapeutic action In heavily infected mice, DNA vaccinations can switch the immune response from one that is relatively inefficient and gives bacterial stasis to one that kills bacteria Application of such immunotherapy in conjunction with conventional chemotherapeutic antibacterial drugs might result in faster or more certain cure of the disease in humans

Pirâmide alimentar adaptada: guia para escolha dos alimentos

Abstract: Este trabalho traz a avaliacao e adaptacao da pirâmide alimentar elaborada nos Estados Unidos em 1992 a realidade profissional brasileira dos grupos de pesquisa em alimentacao e nutricao. A Pirâmide Alimentar Adaptada foi construida com os alimentos distribuidos em oito grupos (cereais, frutas, vegetais, leguminosas, leite, carnes, gorduras e acucares) de acordo com a contribuicao de cada nutriente basico na dieta. Foram estabelecidas tres dietas-padrao (1 600 kcal, 2 200 kcal e 2 800 kcal), com distribuicao dos macronutrientes: carboidratos (50-60%), proteinas (10-15%), lipidios (20-30%). Cada nivel foi apresentado em porcoes minimas e maximas a serem consumidas de acordo com as dietas referidas. Para o calculo das dietas e definicao das porcoes utilizou-se o software "Virtual Nutri". A Pirâmide Alimentar Adaptada pode ser utilizada como instrumento para orientacao nutricional de individuos e grupos populacionais, respeitando-se os habitos alimentares e as diferentes realidades regionais e institucionais.

Pituitary Tumor Transforming Gene (PTTG) Expression in Pituitary Adenomas

Abstract: We recently cloned a novel pituitary tumor transforming gene (PTTG). Here we report PTTG expression in human pituitary adenomas and in normal pituitary tissue. In situ hybridization revealed PTTG expression in nonfunctioning and in GH-secreting adenomas but not in normal pituitary tissue. Using a more sensitive detection method, RT-PCR, low level PTTG expression was detected in normal pituitary. However, when expression levels in normal pituitary tissue were compared with those in 54 pituitary tumors using comparative reverse transcription polymerase chain reaction (RT-PCR), we found that most tumor samples expressed higher levels of PTTG. More than 50% PTTG increases were observed in 23 of 30 nonfunctioning pituitary tumors, all 13 GH-producing tumors, 9 of 10 prolactinomas, and 1 ACTH-secreting tumor, with more than 10-fold increases evident in some tumors. Furthermore, higher PTTG expression (P = 0.03) was observed in hormone-secreting tumors that had invaded the sphenoid bone (stages III and IV; 95% CI 3.118-9.715) compared with hormone-secreting tumors that were confined to the pituitary fossa (stages I and II; 95% CI 1.681-3.051). Therefore, PTTG abundance is a molecular marker for invasiveness in hormone-secreting pituitary tumors. The ubiquitous and prevalent expression of pituitary adenoma PTTG suggests that PTTG plays a role in pituitary tumorigenesis and invasiveness.

Stellar Iron Abundances: Non-LTE Effects

Abstract: We report new statistical equilibrium calculations for Fe I and Fe II in the atmosphere of late-type stars. We used atomic models for Fe I and Fe II having, respectively, 256 and 190 levels, as well as 2117 and 3443 radiative transitions. Photoionization cross sections are from the Iron Project. These atomic models were used to investigate non-LTE (NLTE) effects in iron abundances of late-type stars with different atmospheric parameters. We found that most Fe I lines in metal-poor stars are formed in conditions far from LTE. We derived metallicity corrections of about 0.3 dex with respect to LTE values for the case of stars with [Fe/H] ~ -3.0. Fe II is found not to be affected by significant NLTE effects. The main NLTE effect invoked in the case of Fe I is overionization by ultraviolet radiation; thus classical ionization equilibrium is far from being satisfied. An important consequence is that surface gravities derived by LTE analysis are in error and should be corrected before final abundance corrections. This apparently solves the observed discrepancy between spectroscopic surface gravities derived by LTE analyses and those derived from Hipparcos parallaxes. A table of NLTE [Fe/H] and log g values for a sample of metal-poor late-type stars is given.

Annual growth rings, rainfall‐dependent growth and long‐term growth patterns of tropical trees from the Caparo Forest Reserve in Venezuela

Abstract: 1 Tree-ring analyses and dendrometer measurements were carried out on 37 tree species in a semi-deciduous forest of the Reserva Forestal de Caparo, Venezuela, where the mean annual rainfall is about 1700 mm and there is a dry season from December to March. The main purposes of the investigation were to show the seasonality of cambial growth, and the connection between precipitation patterns and tree-ring curves. Long-term rates of wood increment were also estimated. 2 Cambial markings in consecutive years showed that annual rings were formed by many species. 3 The distinctiveness of growth zones was usually greater in deciduous species than in evergreen species, although not all deciduous species had distinct rings. 4 Dendrometer measurements showed that the annual growth rhythm was related to precipitation patterns. Evergreen species tended to show only a short interruption of wood growth (during the later part of the dry season), whereas deciduous species stopped growth completely at the end of the rainy season. 5 For deciduous species, regression analyses showed close relations between tree-ring width and the sum of precipitation outside the rainy seasons (i.e. November to April). Evergreen species reacted to the total annual amount of precipitation. 6 Variation in longest available ring chronology (for Terminalia guianensis) showed little correlation with the El Nino–Southern Oscillation effect. 7 On average trees from natural forests showed relatively constant growth over the entire life span. Plantation trees grew fast up to an age of 15–20 years, but annual increments then decreased to values seen in natural forest trees.

Submonthly Convective Variability over South America and the South Atlantic Convergence Zone

Abstract: Relationships between deep convection over South America and the atmospheric circulation are examined, with emphasis on submonthly variations of the South Atlantic convergence zone (SACZ) during austral summer Outgoing longwave radiation (OLR) is used as a proxy for convection, while the associated circulation patterns are depicted by the National Centers for Environmental Prediction Reanalysis Over South America and the adjacent oceans, OLR fluctuations with periods less than 90 days show maximum variance in the SACZ and over central South America during December–February There is a local minimum in variance over the southern Amazon Basin, where mean convection is at a maximum OLR spectra display several statistically relevant peaks corresponding to periods of less than 30 days over tropical South America, with the relative proportion of higher-frequency power increasing as the base grid point is moved to the southeast within the SACZ Correlations between submonthly (2–30-day) OLR in the vi

CACP, encoding a secreted proteoglycan, is mutated in camptodactyly-arthropathy-coxa vara-pericarditis syndrome.

Abstract: Altered growth and function of synoviocytes, the intimal cells which line joint cavities and tendon sheaths, occur in a number of skeletal diseases. Hyperplasia of synoviocytes is found in both rheumatoid arthritis and osteoarthritis, despite differences in the underlying aetiologies of the two disorders. We have studied the autosomal recessive disorder camptodactyly-arthropathy-coxa vara-pericarditis syndrome (CACP; MIM 208250) to identify biological pathways that lead to synoviocyte hyperplasia, the principal pathological feature of this syndrome. Using a positional-candidate approach, we identified mutations in a gene (CACP) encoding a secreted proteoglycan as the cause of CACP. The CACP protein, which has previously been identified as both 'megakaryocyte stimulating factor precursor' and 'superficial zone protein', contains domains that have homology to somatomedin B, heparin-binding proteins, mucins and haemopexins. In addition to expression in joint synovium and cartilage, CACP is expressed in non-skeletal tissues including liver and pericardium. The similarity of CACP sequence to that of other protein families and the expression of CACP in non-skeletal tissues suggest it may have diverse biological activities.

State-of-the-Art lecture: influence of exercise training on neurogenic control of blood pressure in spontaneously hypertensive rats.

Abstract: Exercise training plays an important role in the reduction of high blood pressure. In this review, we discuss the effect of distinct intensities of exercise training on the reduction of high blood pressure in spontaneously hypertensive rats (SHR). In addition, we present some hemodynamic mechanisms and associated neural controls by which exercise training attenuates hypertension in SHR. Low-intensity exercise training is more effective in reducing high blood pressure than is high-intensity exercise training in SHR. The decrease in blood pressure is due to resting bradycardia, and in consequence, lower cardiac output. Sympathetic attenuation to the heart is the major explanation for the resting bradycardia. Recovery of the sensitivity of baroreflex control of heart rate, which is usually impaired in SHR, is an important neurogenic component involved in the benefits elicited by exercise training.

Cortical afferents to the extended amygdala.

Abstract: The projections of the cerebral cortex to the extended amygdala were studied in the rat using anterograde and retrograde tract-tracing techniques. Most cortical areas with strong projections to the extended amygdala preferentially targeted either the medial extended amygdala (including the medial amygdalar nucleus, ventromedial substantia innominata, and the medial part of the bed nucleus the stria terminalis) or the central extended amygdala (including the central amygdalar nucleus, dorsolateral substantia innominata, and the lateral part of the bed nucleus of the stria terminalis). Some cortical areas, however, had equal projections to both medial and central portions. The main areas projecting preferentially to the medial extended amygdala were the ventral subiculum, infralimbic cortex, ventral agranular insular area, and the rostral part of the ventrolateral entorhinal area. The main areas projecting preferentially to the central extended amygdala were the prefrontal cortex, viscerosensory and somatosensory portions of the insular cortex, and the amygdalopiriform transitional area. It is suggested that these cortical inputs may be important for cognitive, mnemonic, and affective aspects of emotional and motivated behavior.

Structure, expression, and function of human pituitary tumor-transforming gene (PTTG).

Abstract: Despite advances in characterizing the pathophysiology and genetics of pituitary tumors, molecular mechanisms of their pathogenesis are poorly understood. Recently, we isolated a transforming gene [pituitary tumor-transforming gene (PTTG)] from rat pituitary tumor cells. Here we describe the cloning of human PTTG, which is located on chromosome 5q33 and shares striking sequence homology with its rat counterpart. Northern analysis revealed PTTG expression in normal adult testis, thymus, colon, small intestine, brain, lung, and fetal liver, but most abundant levels of PTTG mRNA were observed in several carcinoma cell lines. Stable transfection of NIH 3T3 cells with human PTTG cDNA caused anchorage-independent transformation in vitro and induced in vivo tumor formation when transfectants were injected into athymic mice. Overexpression of PTTG in transfected NIH 3T3 cells also stimulated expression and secretion of basic fibroblast growth factor, a human pituitary tumor growth-regulating factor. A proline-ric...

Clinical spectrum of fibroblast growth factor receptor mutations.

Abstract: During the last few years, it has been demonstrated that some syndromic craniosynostosis and short-limb dwarfism syndromes, a heterogeneous group comprising of 11 distinct clinical entities, are caused by mutations in one of three fibroblast growth factor receptor genes (FGFR1, FGFR2, and FGFR3). The present review list all mutations described to date in these three genes and the phenotypes associated with them. In addition, the tentative phenotype-genotype correlation is discussed, including the most suggested causative mechanisms for these conditions.

Regional Measurement of Resin-Dentin Bonding as an Array:

Abstract: During the development of the microtensile bond-testing method, large variations in bond strengths were noted among serial sections The reason for these variations is unknown The purpose of this work was to determine the consistency of resin-dentin bond strengths across the occlusal surface of coronal dentin by dividing composite resin buildups into an array of 1x1 mm beams, the top half consisting of composite resin, and the bottom half consisting of dentin Extracted human third molars had the occlusal enamel removed as a single section by means of a diamond saw Resin composite buildups were made after the dentin was bonded with either One-Step or MacBond After being stored in 37 degrees C water for 1 day, the teeth were vertically sectioned at 1-mm increments into slabs of bonded teeth Each slab was further subdivided by vertical sections into 1x1x8 mm beams Each beam was assigned an x-y coordinate and tested for tensile bond strength Two different clinicians (A and B) performed the same procedures using One-Step in a parallel study Using One-Step, clinician A obtained a large number of zero bonds in superficial dentin but fewer in deep dentin This resulted in a very large standard deviation in bond strengths (mean +/- SD of 22+/-20 MPa in superficial dentin and 27+/-14 MPa in deep dentin) Clinician B obtained much higher (p<0001) and more uniform bond strengths with One-Step (56+/-13 MPa in superficial dentin and 57+/-12 MPa in deep dentin) With MacBond, there were no zero bonds and hence less variation, with a mean of 41+/-13 MPa in superficial dentin and 27+/-12 MPa (x +/- SD) in deep dentin When pairs of Z100 resin composite cylinders were bonded together with One-Step and then sectioned into an array, there was little variation in regional bond strength (37 +/-1 MPa) Dividing bonded resin composite buildups into an array of 20 to 30 1x1x8 mm beams allows for the evaluation of uniformity of resin-dentin bonds The method used in this study detected local regional differences in resin-dentin bond strengths The largest differences were shown to be related to technique rather than to material The results indicate that resin-dentin bonds may not be as homogenous as was previously thought

Racism in a Racial Democracy: The Maintenance of White Supremacy in Brazil.

Abstract: Racism in. Racial Democracy: The Maintenance of White Supremacy in Brazil. France Winddance Twine. New Brunswick, NJ: Rutgers University Press, 1998. xiii. 175pp. (Cloth US$49.00, Paper US$17.00)

Thermal Behavior of Nafion Membranes

Abstract: The thermal behavior of Nafion-117 membranes was investigated by thermogravimetric analysis (TG) and differential scanning calorimetry (DSC). TG measurements revealed that the mechanism of thermal degradation of a Nafion membrane in the acid form is different from that of Nafion in the sodium form. The DSC curves for the first heating, for both acid and salt forms, display two endothermic peaks, near 120 and 230°C. The high-temperature peak was assigned to the crystalline domains melting in Nafion, and the low-temperature peak was attributed to a transition into ionic clusters, since this transition exhibits significant changes depending on the nature of the counterion and the degree of hydration.