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.

Polymorphism of the aryl-hydrocarbon receptor gene in intron 10 of human cancers

Polychlorinated dibenzo-p-dioxins (PCDDs) and related halogenated aromatic hydrocarbons (e.g., PCDFs), often called "dioxins", are ubiquitously present environmental contaminants. Some of them, notably 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD), are among the most toxic synthetic compounds known. The biological effects of dioxins are mediated via the aryl hydrocarbon receptor (AhR). Mutations in the AhR transactivation domain are linked to sensitivity to the acute lethality of TCDD. We present here a study of AhR gene polymorphism in normal and cancer human tissues affecting pre-mRNA splicing in the AhR gene-coding transactivation domain region (exon 10, intron 10, exon 11 region), previously shown to be associated with AhR dysfunction. We tested 126 pairs of normal and cancer tissue samples from liver, lung, stomach, kidney, mucous, breast, and pancreas of 49 males and 77 females (45-70 years of age). We used in vitro splicing assay, RT-PCR and sequencing methods. Our results showed that in an in vitro system it is possible to reconstitute cellular pre-mRNA splicing events. Tested cancer tissues did not contain mutations in the AhR transactivation domain region when the DNA sequences were compared with those from normal tissues. There were also no differences in AhR mRNA splice variants between normal and malignant breast tissues and no polymorphisms in the studied regions or cDNA.

Loss of Y-chromosome does not correlate with age at onset of head and neck carcinoma: a case-control study

Loss of Y-chromosome has been correlated with older age in males. Furthermore, current evidence indicates that Y-chromosome loss also occurs in several human tumors, including head and neck carcinomas. However, the association between Y nullisomy and the occurrence of neoplasias in elderly men has not been well established. In the present study, the association between Y-chromosome loss and head and neck carcinomas was evaluated by comparison to cells from peripheral blood lymphocytes and normal mucosa of cancer-free individuals matched for age using dual-color fluorescence in situ hybridization. Twenty-one patients ranging in age from 28 to 68 years were divided into five-year groups for comparison with 16 cancer-free individuals matched for age. The medical records of all patients were examined to obtain clinical and histopathological data. None of the patients had undergone radiotherapy or chemotherapy before surgery. In all groups, the frequency of Y-chromosome loss was higher among patients than among normal reference subjects (P < 0.0001) and was not age-dependent. These data suggest that Y-chromosome loss is a tumor-specific alteration not associated with advanced age in head and neck carcinomas.

Myosin Va is developmentally regulated and expressed in the human cerebellum from birth to old age

Myosin Va functions as a processive, actin-based motor molecule highly enriched in the nervous system, which transports and/or tethers organelles, vesicles, and mRNA and protein translation machinery. Mutation of myosin Va leads to Griscelli disease that is associated with severe neurological deficits and a short life span. Despite playing a critical role in development, the expression of myosin Va in the central nervous system throughout the human life span has not been reported. To address this issue, the cerebellar expression of myosin Va from newborns to elderly humans was studied by immunohistochemistry using an affinity-purified anti-myosin Va antibody. Myosin Va was expressed at all ages from the 10th postnatal day to the 98th year of life, in molecular, Purkinje and granular cerebellar layers. Cerebellar myosin Va expression did not differ essentially in localization or intensity from childhood to old age, except during the postnatal developmental period. Structures resembling granules and climbing fibers in Purkinje cells were deeply stained. In dentate neurons, long processes were deeply stained by anti-myosin Va, as were punctate nuclear structures. During the first postnatal year, myosin Va was differentially expressed in the external granular layer (EGL). In the EGL, proliferating prospective granule cells were not stained by anti-myosin Va antibody. In contrast, premigratory granule cells in the EGL stained moderately. Granule cells exhibiting a migratory profile in the molecular layer were also moderately stained. In conclusion, neuronal myosin Va is developmentally regulated, and appears to be required for cerebellar function from early postnatal life to senescence.

Abundant immunohistochemical expression of dopamine D2 receptor and p53 protein in meningiomas: follow-up, relation to gender, age, tumor grade, and recurrence

Meningiomas are common, usually benign tumors, with a high postoperative recurrence rate. However, the genesis and development of these tumors remain controversial. We aimed to investigate the presence and implications of a mutated p53 protein and dopamine D2 receptor in a representative series of meningiomas and to correlate these findings with age, gender, tumor grade, and recurrence. Tumor tissue samples of 157 patients diagnosed with meningioma (37 males and 120 females, mean age 53.6±14.3 years) who underwent surgical resection between 2003 and 2012 at our institution were immunohistochemically evaluated for the presence of p53 protein and dopamine D2 receptor and were followed-up to analyze tumor recurrence or regrowth. Tumors were classified as grades I (n=141, 89.8%), II (n=13, 8.3%), or grade III (n=3, 1.9%). Dopamine D2 receptor and p53 protein expression were positive in 93.6% and 49.7% of the cases, respectively. Neither of the markers showed significant expression differences among different tumor grades or recurrence or regrowth statuses. Our findings highlight the potential role of p53 protein in meningioma development and/or progression. The high positivity of dopamine D2 receptor observed in this study warrants further investigation of the therapeutic potential of dopamine agonists in the evolution of meningiomas.

Study of carbohydrates present in the cladodes of Opuntia ficus-indica (fodder palm), according to age and season

Types and content of carbohydrates were evaluated by chemical (spectrophotometric assay) and physicochemical (Thin Layer Chromatography - TLC and High Performance Liquid Chromatography - HPLC) methods in some Opuntia ficus-indica varieties according to age and season. The samples comprised four varieties of palm (giant, copena F1, clone 20, and round palm). The results demonstrated that the four varieties of palm contain a good quantity of neutral and acid sugars in both summer and winter seasons. However, samples collected in the summer presented a higher content of carbohydrates specially glucose, fructose, galactose, xylose, and arabinose. The tertiary cladode (old cladode) presented almost the double content of sugar found in the quaternary cladodes (young cladodes). Pectic polysaccharides were sequentially extracted with water at 60 ºC, and EDTA at 60 ºC solution resulting in Water-Soluble Pectin (WSP) and a Chelating-Soluble Pectin (CSP) respectively. Galacturonic acid was detected in the fractions WSP and CSP. However, the fraction CSP presented the highest content of sugar acid.

Effect of pre and post-slaughter processes on meat characteristics of Santa Ines ewes discarded due to age

The effects of body condition recovery (BC), carcass electrical stimulation (ES), aging time (AT 7 - 14 days), and calcium chloride injection on the meat characteristics of Santa Inês ewes (±5 years old) slaughtered immediately after weaning or after the body condition recovery period were studied. The carcass temperature, pH, shear force (SF), cooking loss (CL), meat color (L*, a*, b*), and meat tenderness were evaluated. A completely randomized design in a 2 × 2 × 2 × 3 (BC × ES × CaCl2 × AT) factorial arrangement was used, and the sensory tenderness data were analyzed using the table of Minimum Number of Correct Answers for the Duo-Trio test. The body condition recovery reduces the shear force in 8%, increasing their tenderness. Electrical stimulation reduced the shear force (24%) and did not change the other parameters. The aging time (7 or 14 days) decreased the shear force (18-26%), effect that was enhanced by electrical stimulation, and it darkened the meat reducing lightness (L*) and increasing yellowness (b*). The treatment with CaCl2 was the most effective in tenderizing meat by reducing the shear force ( 35%); increasing the cooking loss (4.5%); and increasing L* and b* lightening the meat. The sensory evaluation of tenderness corroborates the findings of the experimental evaluation regarding the effect of the treatment with CaCl2 on the meat quality improvement. It was concluded that the treatments improve meat characteristics achieving better results when applied together.

Inconvenient glow: cliometrics and the "golden age" of capitalism

This paper aims to criticize the recent cliometrics literature on the so-called "golden age" of capitalism. The works of Nicholas Crafts, Gianni Toniolo, and Barry Eichengreen are reconstructed in order to reveal the main characteristics of this research program. Its narrow quantitative focus, its reliance on theoretical propositions borrowed from neoclassical economics, and its auspicious interpretation of the postwar reconstruction are the main focus of the criticism presented. Finally, the cliometricians' attempt to historicize the "golden age" and de-historicize the following decades is related to the ideological understanding of the recent decades as a period of "great moderation."

From restrained golden age to creeping platinum age: A periodization of Latin American development in the Robinsonian tradition

ABSTRACTThis paper analyzes Joan Robinson's growth model, and then adapted in order to provide an exploratory taxonomy of Growth Eras. The Growth Eras or Ages were for Robinson a way to provide logical connections among output growth, capital accumulation, the degree of thriftiness, the real wage and illustrate a catalogue of growth possibilities. This modified taxonomy follows the spirit of Robinson's work, but it takes different theoretical approaches, which imply that some of her classifications do not fit perfectly the ones here suggested. Latin America has moved from a Golden Age in the 1950s and 1960s, to a Leaden Age in the 1980s, having two traverse periods, one in which the process of growth and industrialization accelerated in the late 1960s and early 1970s, which is here referred to as a Galloping Platinum Age, and one in which a process of deindustrialization, and reprimarization and maquilization of the productive structure took place, starting in the 1990s, which could be referred to as a Creeping Platinum Age.