Interrelationship between adipocytes and fibroblasts during acute damage to the subcutaneous adipose tissue of rats: an ultrastructural study

Ultrastructural phenotypic transitional features were noted between adult adipocytes and fibroblasts in the subcutaneous adipose tissue of the dorsal pad of normal adult Wistar rats of both sexes, weighing 180-260 g, after acute injury either by the implantation of small (1.8 x 1 x 0.4 cm) perforated plastic boxes or by local heat application. Soon after the inflicted damage, fat-containing cells presented variable shapes. Early after damage, some of these cells were round, adipocyte-like, with numerous and large cytoplasmic fat droplets. A few days later, fat-containing cells became elongated, with the fat droplets in their cytoplasm becoming smaller and less numerous. The cells also showed a prominent active rough endoplasmic reticulum and newly formed collagenous matrix accumulated in the interstices. Although current views consider adult adipocytes to be terminal cells, the present findings, in their time sequence, strongly suggest the transformation of adipocytes into fibroblasts after acute injury to adipose tissue.

Upper esophageal sphincter pressure in patients with Chagas' disease and primary achalasia

The most important component of the upper esophageal sphincter (UES) is the cricopharyngeal muscle. During the measurement of sphincter pressure the catheter passed through the sphincter affects the pressure value. In Chagas' disease and primary achalasia there is an esophageal myenteric plexus denervation which may affect UES pressure. We measured the UES pressure of 115 patients with Chagas' disease, 28 patients with primary achalasia and 40 healthy volunteers. We used a round manometric catheter with continuous perfusion and the rapid pull-through method, performed in triplicate during apnea. Pressures were measured in four directions, and the direction with the highest pressure (anterior/posterior) and the average of the four directions were measured. The highest UES pressure in Chagas' disease patients without abnormalities upon radiologic esophageal examination (N = 63) was higher than in normal volunteers (142.8 ± 47.4 mmHg vs 113.0 ± 46.0 mmHg, mean ± SD, P<0.05). There was no difference in UES pressure between patients with primary achalasia and patients with Chagas' disease and similar esophageal involvement and normal volunteers (P>0.05). There was no difference between patients with or without esophageal dilation. In the group of subjects less than 50 years of age the UES pressure of primary achalasia (N = 21) was lower than that of Chagas' disease patients with normal radiologic esophageal examination (N = 41), measured at the site with the highest pressure (109.3 ± 31.5 mmHg vs 149.6 ± 45.3 mmHg, P<0.01) and as the average of the four directions (64.2 ± 17.1 mmHg vs 83.5 ± 28.6 mmHg, P<0.05). We conclude that there is no difference in UES pressure between patients with Chagas' disease, primary achalasia and normal volunteers, except for patients with minor involvement by Chagas' disease, for whom the UES pressure at the site with the highest pressure was higher than the pressure of normal volunteers and patients with primary achalasia.

Sulfated proteoglycans as modulators of neuronal migration and axonal decussation in the developing midbrain

Proteoglycans are abundant in the developing brain and there is much circumstantial evidence for their roles in directional neuronal movements such as cell body migration and axonal growth. We have developed an in vitro model of astrocyte cultures of the lateral and medial sectors of the embryonic mouse midbrain, that differ in their ability to support neuritic growth of young midbrain neurons, and we have searched for the role of interactive proteins and proteoglycans in this model. Neurite production in co-cultures reveals that, irrespective of the previous location of neurons in the midbrain, medial astrocytes exert an inhibitory or nonpermissive effect on neuritic growth that is correlated to a higher content of both heparan and chondroitin sulfates (HS and CS). Treatment of astrocytes with chondroitinase ABC revealed a growth-promoting effect of CS on lateral glia but treatment with exogenous CS-4 indicated a U-shaped dose-response curve for CS. In contrast, the growth-inhibitory action of medial astrocytes was reversed by exogenous CS-4. Treatment of astrocytes with heparitinase indicated that the growth-inhibitory action of medial astrocytes may depend heavily on HS by an as yet unknown mechanism. The results are discussed in terms of available knowledge on the binding of HS proteoglycans to interactive proteins, with emphasis on the importance of unraveling the physiological functions of glial glycoconjugates for a better understanding of neuron-glial interactions.

Colocalization of coilin and nucleolar proteins in Cajal body-like structures of micronucleated PtK2 cells

Cajal bodies (CB) are ubiquitous nuclear structures involved in the biogenesis of small nuclear ribonucleoproteins and show narrow association with the nucleolus. To identify possible relationships between CB and the nucleolus, the localization of coilin, a marker of CB, and of a set of nucleolar proteins was investigated in cultured PtK2 cells undergoing micronucleation. Nocodazol-induced micronucleated cells were examined by double indirect immunofluorescence with antibodies against coilin, fibrillarin, NOR-90/hUBF, RNA polymerase I, PM/Scl, and To/Th. Cells were imaged on a BioRad 1024-UV confocal system attached to a Zeiss Axiovert 100 microscope. Since PtK2 cells possess only one nucleolus organizer region, micronucleated cells presented only one or two micronuclei containing nucleolus. By confocal microscopy we showed that in most micronuclei lacking a typical nucleolus a variable number of round structures were stained by antibodies against fibrillarin, NOR-90/hUBF protein, and coilin. These bodies were regarded as CB-like structures and were not stained by anti-PM/Scl and anti-To/Th antibodies. Anti-RNA polymerase I antibodies also reacted with CB-like structures in some micronuclei lacking nucleolus. The demonstration that a set of proteins involved in RNA/RNP biogenesis, namely coilin, fibrillarin, NOR-90/hUBF, and RNA polymerase I gather in CB-like structures present in nucleoli-devoid micronuclei may contribute to shed some light into the understanding of CB function.

Estrogens and male reproduction: a new concept

The mammalian testis serves two main functions: production of spermatozoa and synthesis of steroids; among them estrogens are the end products obtained from the irreversible transformation of androgens by a microsomal enzymatic complex named aromatase. The aromatase is encoded by a single gene (cyp19) in humans which contains 18 exons, 9 of them being translated. In rats, the aromatase activity is mainly located in Sertoli cells of immature rats and then in Leydig cells of adult rats. We have demonstrated that germ cells represent an important source of estrogens: the amount of P450arom transcript is 3-fold higher in pachytene spermatocytes compared to gonocytes or round spermatids; conversely, aromatase activity is more intense in haploid cells. Male germ cells of mice, bank voles, bears, and monkeys express aromatase. In humans, we have shown the presence of a biologically active aromatase and of estrogen receptors (alpha and ß) in ejaculated spermatozoa and in immature germ cells in addition to Leydig cells. Moreover, we have demonstrated that the amount of P450arom transcripts is 30% lower in immotile than in motile spermatozoa. Alterations of spermatogenesis in terms of number and motility of spermatozoa have been described in men genetically deficient in aromatase. These last observations, together with our data showing a significant decrease of aromatase in immotile spermatozoa, suggest that aromatase could be involved in the acquisition of sperm motility. Thus, taking into account the widespread localization of aromatase and estrogen receptors in testicular cells, it is obvious that, besides gonadotrophins and androgens, estrogens produced locally should be considered to be physiologically relevant hormones involved in the regulation of spermatogenesis and spermiogenesis.

Dose-response effects of systemic anandamide administration in mice sequentially submitted to the open field and elevated plus-maze tests

The endocannabinoid system is involved in the control of many physiological functions, including the control of emotional states. In rodents, previous exposure to an open field increases the anxiety-like behavior in the elevated plus-maze. Anxiolytic-like effects of pharmacological compounds that increase endocannabinoid levels have been well documented. However, these effects are more evident in animals with high anxiety levels. Several studies have described characteristic inverted U-shaped dose-response effects of drugs that modulate the endocannabinoid levels. However, there are no studies showing the effects of different doses of exogenous anandamide, an endocannabinoid, in animal models of anxiety. Thus, in the present study, we determined the dose-response effects of exogenous anandamide at doses of 0.01, 0.1, and 1.0 mg/kg in C57BL/6 mice (N = 10/group) sequentially submitted to the open field and elevated plus-maze. Anandamide was diluted in 0.9% saline, ethyl alcohol, Emulphor® (18:1:1) and administered ip (0.1 mL/10 g body weight); control animals received the same volume of anandamide vehicle. Anandamide at the dose of 0.1 mg/kg (but not of 0.01 or 1 mg/kg) increased (P < 0.05) the time spent and the distance covered in the central zone of the open field, as well as the exploration of the open arms of the elevated plus-maze. Thus, exogenous anandamide, like pharmacological compounds that increase endocannabinoid levels, promoted a characteristic inverted U-shaped dose-response effect in animal models of anxiety. Furthermore, anandamide (0.1 mg/kg) induced an anxiolytic-like effect in the elevated plus-maze (P < 0.05) after exposing the animals to the open field test.

Effects of strain and age on ear wound healing and regeneration in mice

Round holes in the ears of MRL mice tend to close with characteristics of regeneration believed to be absent in other mouse strains (e.g., C57BL/6). We evaluated the kinetics and the histopathology of ear wound closure in young (8 weeks old) C57BL/6 and BALB/c mice. We also used middle-aged (40 weeks old) C57BL/6 mice to evaluate the influence of aging on this process. A circular through-and-through hole was made in the ear, photographs were taken at different times after injury and wound area was measured with digital analysis software. The percentages of closed area measured on day 100 were: 23.57 ± 8.66% for young BALB/c mice, 56.47 ± 7.39% for young C57BL/6 mice, and 75.31 ± 23.65% for middle-aged C57BL/6 mice. Mice were sacrificed on days 1, 3, 5, 25, 44, and 100 for histological evaluation with hematoxylin and eosin, Gomori’s trichrome, periodic acid-Schiff, or picrosirius red staining. In young mice of both strains, healing included re-epithelialization, chondrogenesis, myogenesis, and collagen deposition. Young C57BL/6 and BALB/c mice differed in the organization of collagen fibers visualized using picrosirius-polarization. Sebaceous glands and hair follicles regenerated and chondrogenesis was greater in young C57BL/6 mice. In middle-aged C57BL/6 mice all aspects of regeneration were depressed. The characteristics of regeneration were present during ear wound healing in both young BALB/c and young C57BL/6 mice although they differed in intensity and pattern. Greater ear wound closure in middle-aged C57BL/6 mice was not correlated with regeneration.

Do Caucasian and Asian clocks tick differently?

The Period 3 and Clock genes are important components of the mammalian molecular circadian system. Studies have shown association between polymorphisms in these clock genes and circadian phenotypes in different populations. Nevertheless, differences in the pattern of allele frequency and genotyping distribution are systematically observed in studies with different ethnic groups. To investigate and compare the pattern of distribution in a sample of Asian and Caucasian populations living in Brazil, we evaluated two well-studied polymorphisms in the clock genes: a variable number of tandem repeats (VNTR) in PER3 and a single nucleotide polymorphism (SNP) in CLOCK. The aim of this investigation was to search for clues about human evolutionary processes related to circadian rhythms. We selected 109 Asian and 135 Caucasian descendants. The frequencies of the shorter allele (4 repeats) in the PER3 gene and the T allele in the CLOCK gene among Asians (0.86 and 0.84, respectively) were significantly higher than among Caucasians (0.69 and 0.71, respectively). Our results directly confirmed the different distribution of these polymorphisms between the Asian and Caucasian ethnic groups. Given the genetic differences found between groups, two points became evident: first, ethnic variations may have implications for the interpretation of results in circadian rhythm association studies, and second, the question may be raised about which evolutionary conditions shaped these genetic clock variations.

In vitro inhibitory effects of imatinib mesylate on stromal cells and hematopoietic progenitors from bone marrow

Imatinib mesylate (IM) is used to treat chronic myeloid leukemia (CML) because it selectively inhibits tyrosine kinase, which is a hallmark of CML oncogenesis. Recent studies have shown that IM inhibits the growth of several non-malignant hematopoietic and fibroblast cells from bone marrow (BM). The aim of the present study was to evaluate the effects of IM on stromal and hematopoietic progenitor cells, specifically in the colony-forming units of granulocyte/macrophage (CFU-GM), using BM cultures from 108 1.5- to 2-month-old healthy Swiss mice. The results showed that low concentrations of IM (1.25 µM) reduced the growth of CFU-GM in clonogenic assays. In culture assays with stromal cells, fibroblast proliferation and α-SMA expression by immunocytochemistry analysis were also reduced in a concentration-dependent manner, with a survival rate of approximately 50% with a dose of 2.5 µM. Cell viability and morphology were analyzed using MTT and staining with acrydine orange/ethidium bromide. Most cells were found to be viable after treatment with 5 µM IM, although there was gradual growth inhibition of fibroblastic cells while the number of round cells (macrophage-like cells) increased. At higher concentrations (15 µM), the majority of cells were apoptotic and cell growth ceased completely. Oil red staining revealed the presence of adipocytes only in untreated cells (control). Cell cycle analysis of stromal cells by flow cytometry showed a blockade at the G0/G1 phases in groups treated with 5-15 µM. These results suggest that IM differentially inhibits the survival of different types of BM cells since toxic effects were achieved.

Oxidative stress and cellular immunity in patients with recurrent aphthous ulcers

Recurrent aphthous ulcer (RAU) is an inflammatory condition of the oral mucosa characterized by painful, well-circumscribed, single or multiple round or ovoid ulcerations. The exact etiologic factor(s) of these ulcerations are not yet understood. The objective of this study was to evaluate inflammatory processes and free radical metabolism of 25 patients with RAUs compared to 25 healthy controls. The levels of malondialdehyde (MDA) and glutathione (GSH) were determined by high-performance liquid chromatography. Tumor necrosis factor-alpha (TNF-α), interleukin-2 (IL-2), IL-10, and IL-12 were determined by ELISA. Nitric oxide (NO), myeloperoxidase (MPO), total antioxidant status (TAS), and total oxidant status (TOS) levels were measured spectroscopically in serum. The levels of MDA, GSH, TNF-α, IL-2, IL-12, MPO, and TOS, and oxidative stress index (OSI) were higher, and the levels of NO, IL-10, and TAS were lower in patients with RAU than in controls. Statistical analysis showed that GSH, TNF-α, IL-2, IL-10, and OSI differed significantly in patients with RAU compared to controls. These parameters have important roles in oxidant/antioxidant defense.

Microparticles obtained by complex coacervation: influence of the type of reticulation and the drying process on the release of the core material

Microparticles obtained by complex coacervation were crosslinked with glutaraldehyde or with transglutaminase and dried using freeze drying or spray drying. Moist samples presented Encapsulation Efficiency (%EE) higher than 96%. The mean diameters ranged from 43.7 ± 3.4 to 96.4 ± 10.3 µm for moist samples, from 38.1 ± 5.36 to 65.2 ± 16.1 µm for dried samples, and from 62.5 ± 7.5 to 106.9 ± 26.1 µm for rehydrated microparticles. The integrity of the particles without crosslinking was maintained when freeze drying was used. After spray drying, only crosslinked samples were able to maintain the wall integrity. Microparticles had a round shape and in the case of dried samples rugged walls apparently without cracks were observed. Core distribution inside the particles was multinuclear and homogeneous and core release was evaluated using anhydrous ethanol. Moist particles crosslinked with glutaraldehyde at the concentration of 1.0 mM.g-1 protein (ptn), were more efficient with respect to the core retention compared to 0.1 mM.g-1 ptn or those crosslinked with transglutaminase (10 U.g-1 ptn). The drying processes had a strong influence on the core release profile reducing the amount released to all dry samples

Anthocyanins standards (cyanidin-3-O-glucoside and cyanidin-3-O-rutinoside) isolation from freeze-dried açaí (Euterpe oleraceae Mart.) by HPLC

Availability of analytical standards is a critical aspect in developing methods for quantitative analysis of anthocyanins. The anthocyanins cyanidin-3-O-glucoside and cyanidin-3-O-rutinoside were isolated from samples of freeze-dried açaí (Euterpe oleraceae Mart.), which is a round and purple well-known palm fruit in Brazil, and then used as standards. The isolation of the anthocyanins was performed by High Performance Liquid Chromatography (HPLC), using an adapted six-channel selection valve. The identification of anthocyanin pigments in açaí was based on mass spectrometric data for molecular ions and MS-MS product ions and on previous published data. After the collection procedure, standards with a high purity grade were obtained and an external standard curve of each anthocyanin was plotted.

Computational fluid dynamics evaluation of liquid food thermal process in a brick shaped package

Food processes must ensure safety and high-quality products for a growing demand consumer creating the need for better knowledge of its unit operations. The Computational Fluid Dynamics (CFD) has been widely used for better understanding the food thermal processes, and it is one of the safest and most frequently used methods for food preservation. However, there is no single study in the literature describing thermal process of liquid foods in a brick shaped package. The present study evaluated such process and the influence of its orientation on the process lethality. It demonstrated the potential of using CFD to evaluate thermal processes of liquid foods and the importance of rheological characterization and convection in thermal processing of liquid foods. It also showed that packaging orientation does not result in different sterilization values during thermal process of the evaluated fluids in the brick shaped package.

Narratives of emergence: rising powers and the end of the Third World?

This article examines recent arguments from development economists, from historians and from international relations specialists that do challenge the continued relevance of the idea of the Third World. It then examines five reasons why these arguments are wrong. We can indeed understand much about emerging powers in terms of how they are seeking to navigate and best position themselves within an existing state-centric, liberal and capitalist order whilst accepting many of the underlying assumptions and values of that order. But the nature of that navigation has been shaped by their historical trajectory and by the developmental, societal and geopolitical context of their emergence.