Kinetics of photoinduced birefringence in the guest-host system of poly(methyl methacrylate) doped with azobenzene-containing crown ethers

The kinetics of the buildup and decay of photoinduced birefringence was examined in a series of host-guest systems: azobenzene-containing crown ethers, differing in the size of the crowns, dissolved in a poly (methyl methacrylate) matrix. In all samples, the kinetics of the buildup of the birefringence was reasonably described by a sum of two exponential functions, the time constants being inversely proportional to the intensity of the pumping light and the magnitudes of the signals at the saturation level depending on the pumping light intensity and sample thickness. The dark decays were best described by the stretched exponential function, with the characteristic parameters (time constant and stretch coefficient) being practically independent of the type of crown ether. The time constants of the signal decay were orders of magnitude shorter than the respective constants of the dark isomerization of the azo crown ethers, thus indicating that the process controlling the decay was a relaxation of the polymer matrix and/or a rearrangement of the flexible parts of the crowns. (C) 2007 Wiley Periodicals, Inc.

Brazilian health regions and scales: A geographical perspective

This paper offers a geographical perspective on the way in which health regions have been defined and established in São Paulo as part of overall Brazilian health policy. To accomplish this, I first situate the Brazilian case in the international debate over the regionalization of health services. Second, I examine health regionalization in the case of São Paulo and show how the process is dynamic and complex, involving geographical scales that go well beyond the administrative boundaries of Brazilian municipalities.

Downregulation of the RECK-tumor and metastasis suppressor gene in glioma invasiveness

Invasive behavior is the pathological hallmark of malignant gliomas, being responsible for the failure of surgery, radiation, and chemotherapy. Matrix metalloproteinases (MMPs) are essential for proper ECM remodeling and invasion. The tumor and metastasis suppressor RECK protein regulates at least three members of the MMPs family: MMP-2, MMP-9, and MT1-MMP. In order to mimic the in vivo invasion process, A172 and T98G, respectively, non-invasive and invasive human glioblastoma cell lines, were cultured onto uncoated (control) or type I collagen gel-coated surface, and maintained for up to 7 days to allow establishment of the invasive process. We show that the collagen substrate causes decreased growth rates and morphological alterations correlated with the invasive phenotype. Electronic transmission microscopy of T98G cells revealed membrane invaginations resembling podosomes, which are typically found in cells in the process of crossing tissue boundaries, since they constitute sites of ECM degradation. Real time PCR revealed higher RECK mRNA expression in A172 cells, when compared to T98G cells and, also, in samples obtained from cultures where the invasive process was fully established. Interestingly, the collagen substrate increases RECK expression in A172 cells and the same tendency is displayed by T98G cells. MMPs-2 and -9 displayed higher levels of expression and activity in T98G cells, and their activities are also upregulated by collagen. Therefore, we suggest that: (1) RECK down regulation is critical for the invasiveness process displayed by T98G cells; (2) type 1 collagen could be employed to modulate RECK expression in glioblastoma cell lines. Since a positive correlation between RECK expression and patients survival has been noted in several types of tumors, our results may contribute to elucidate the complex mechanisms of malignant gliomas invasiveness.

Proxy-reported health-related quality of life of patients with juvenile idiopathic arthritis: Pediatric rheumatology international trials organization multinational quality of life cohort study

Objective. To investigate the proxy-reported health-related quality of life (HRQOL) and its determinants in patients with juvenile idiopathic arthritis (JIA).Methods. In this multinational, multicenter, cross-sectional study, HRQOL of patients with JIA was assessed through the Child Health Questionnaire (CHQ) and was compared with that of healthy children of similar age from the same geographic area. of joint inflammation, Childhood Health Assessment Questionnaire (CHAQ), and erythrocyte sedimentation rate.Results. A total of 6,639 participants (3,324 with JIA and 3,315 healthy) were enrolled from 32 countries. The mean SD physical and psychosocial summary scores of the CHQ were significantly lower in patients with JIA than in healthy children (physical: 44.5 +/- 10.6 versus 54.6 +/- 4.0, P < 0.0001; psychosocial: 47.6 +/- 8.7 versus 51.9 +/- 7.59 P < 0.0001), with the physical well-being domain being most impaired. Patients with persistent oligoarthritis had better HRQOL compared with other subtypes, whereas HRQOL was similar across patients with systemic arthritis, polyarthritis, and extended oligoarthritis. A CHAQ score > 1 and a pain intensity rating > 3.4 cm on a 10-cm visual analog scale were the strongest determinants of poorer HRQOL in the physical and psychosocial domains, respectively.Conclusion. We found that patients with JIA have a significant impairment of their HRQOL compared with healthy peers, particularly in the physical domain. Physical well-being was mostly affected by the level of functional impairment, whereas the intensity of pain had the greatest influence on psychosocial health.

Expression of LH receptor mRNA splice variants in bovine granulosa cells: Changes with follicle size and regulation by FSH in vitro

In cattle, most evidence suggests that granulosa cells express LH receptors (LHR) after (or as) the follicle becomes dominant, however there is some suggestion that granulosa cells from smaller pre-dominant follicles may express several LHR mRNA splice variants. The objective of this study was to measure LHR expression in bovine follicles of defined size and steroiclogenic ability, and in granulosa cells from small follicles (< 6 mm diameter) undergoing differentiation in vitro. Serniquantitative RT-PCR demonstrated that LHR mRNA was undetectable in granulosa cells of follicles < 7 mm diameter (nondominant follicles), and increased with follicle diameter in follicles > 7 mm diameter. Splice variants with deletions of exon 10 and part of exon 11 were detected as previously described, and we detected a novel splice variant with a deletion of exon 3. Cultured granulosa cells contained LHR mRNA, but with significantly greater amounts of variants with deletions of exon 10 and/or exon 11 compared with cells from dominant follicles. FSH increased the abundance of some but not all LHR mRNA splice variants in cultured granulosa cells. The addition of LH to cultured cells did not increase progesterone secretion, despite the presence of LHR mRNA. Collectively, these data suggest that granulosa cells do not acquire functional LHR until follicle dominance occurs.

Small-angle X-ray scattering study of the smart thermo-optical behavior of zirconyl aqueous colloids

The smart thermo-optical systems studied here are based on the unusual thermoreversible sol-gel transition of zirconyl chloride aqueous solution modified by sulfuric acid in the molar ratio Zr/SO4:3/1. The transparency to the visible light changes during heating due to light scattering. This feature is related to the aggregates growth that occurs during gelation. These reversible changes can be controlled by the amount of chloride ions in solution. The thermoreversible sol-gel transition temperature increases from 323 to 343 K by decreasing the molar ratio Cl/Zr from 7.0 to 1.3. In this work the effect of the concentration of chloride ions on the structural characteristics of the system has been analyzed by in situ SAXS measurements during the sol-gel transition carried out at 323 and 333 K. The experimental SAXS curves of sols exhibit three regions at small, medium and high scattering vectors characteristics of Guinier, fractal and Porod regimes, respectively. The radius of primary particles, obtained from the crossover between the fractal and Porod regimes, remains almost invariable with the chloride concentration, and the value (4 Angstrom) is consistent with the size of the molecular precursor. During the sol-gel transition the aggregates grow with a fractal structure and the fractal dimensionality decreases from 2.4 to 1.8. This last value is characteristic of a cluster-cluster aggregation controlled by a diffusion process. Furthermore, the time exponent of aggregate growth presents values of 0.33 and 1, typical of diffusional and hydrodynamic motions. A crossover between these two regimes is observed.

Osteoblasts engulf apoptotic bodies during alveolar bone formation in the rat maxilla

During bone formation, as in other tissues and organs, intense cellular proliferation and differentiation are usually observed. It has been described that programmed cell death, i.e., apoptosis, takes place in the control of the cellular population by removing of the excessive and damaged cells. Although it is generally accepted that apoptotic bodies are engulfed by professional phagocytes, the neighboring cells can also take part in the removal of apoptotic bodies. In the present study, regions of initial alveolar bone formation of rat molars were examined with the aim to verify whether osteoblasts are capable of engulfing apoptotic bodies, such as professional phagocytes. Rats aged 11-19 days were sacrificed and the maxillary fragments containing the first molar were removed and immersed in the fixative solution. The specimens fixed in glutaraldehyde-formaldehyde were processed for light microscopy and transmission electron microscopy. For the detection of apoptosis, the specimens were fixed in formaldehyde, embedded in paraffin, and submitted to the TUNEL method. The results revealed round/ovoid structures containing dense bodies on the bone surface in close contact to osteoblasts and in conspicuous osteoblast vacuoles. These round/ovoid structures showed also positivity to the TUNEL method, indicating that bone cells on the bone surface are undergoing apoptosis. Ultrathin sections showed images of apoptotic bodies being engulfed by osteoblasts. Occasionally, the osteoblasts exhibited large vacuoles containing blocks of condensed chromatin and remnants of organelles. Thus, these images suggest that osteoblasts are able to engulf and degrade apoptotic bodies. (c) 2005 Wiley-Liss, Inc.

Sufentanil-2-hydroxypropyl-beta-cyclodextrin inclusion complex for pain treatment: Physicochemical, cytotoxicity, and pharmacological evaluation

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Amifostine protective effect on cisplatin-treated rat testis

Cisplatin is a potent drug used in clinical oncology but causes spermatogenesis damage. Amifostine is a drug used against toxicity caused by ionizing irradiation and chemotherapeutic drugs. Since cisplatin provokes fertility and induces germ cell apoptosis and necrosis, we proposed to evaluate the amifostine cytoprotective action on testes of cisplatin-treated rats. Thirty-day-old prepubertal Wistar rats received a single cisplatin dose of 5 mg/kg and were killed after 3, 6, and 12 hr. The hematoxylin-eosin stained testicular sections were submitted to histological, morphometric, and stereological analysis. The terminal deoxynucleotidyl transferase-mediated deoxyuridinetriphosphate nick end-labeling (TUNEL) method was used to label apoptotic cells. TUNEL-positive and TUNEL-negative germ cells with abnormal nuclear morphology (ANM) were scored. Significant alterations of greater part of the parameters occurred in the cisplatin-treated group (CE) compared to the group that received amifostine before the cisplatin-treatment (ACE); however, testicular weight and volume did not vary between these groups. Tubular diameter was reduced in CE in comparison to ACE rats, while interstitial tissue and lymphatic space volume and volume density were significantly higher in CE rats; interstitial testicular edema probably occurred in cisplatin-treated rats. CE rats showed important histological alterations, which were more accentuated than in ACE rats. The numerical densities of apoptotic germ cells and TUNEL-negative cells with ANM were lower in ACE than in CE rats. In conclusion, the amifostine previously administered to prepubertal rats reduced the testicular damage caused by cisplatin. We conclude that amifostine partially protected the rat seminiferous epithelium against cisplatin toxicity.