Inflammatory pseudotumor of the parotid gland: report of a case with fine needle aspiration cytology

BACKGROUND: Inflammatory pseudotumor is a rare lesion of the parotid gland. It usually presents as a mass lesion; thus, the clinical and radiologicfeatures often suggest malignancy. To the best of our knowledge, fine needle aspiration cytologic findings in parotid inflammatory pseudotumor have not been reported previously. CASE: A 59-year-old male presented with a palpable right parotid mass. Computed tomography revealed a mass measuring 2.5 cm in diameter. Fine needle aspiration cytology showed inflammatory cells, foamy histiocytes and groups of spindle-shaped cells without cytologic atypia. A diagnosis of inflammatory pseudotumor was suggested and was confirmed on histology. CONCLUSION: In the presence of a clinically evident mass in the parotid gland and fine needle aspiration cytologic features of inflammatory cells with sheets of spindle cells, the diagnosis of inflammatory pseudotumor should be suspected. The differential diagnosis of this unusual parotid gland lesion principally includes sialadenitis and myoepithelioma.     

Function of Drg1/Rit42 in p53-dependent mitotic spindle checkpoint

Mutations in the Drg1/RTP/Rit42 gene are commonly identified in hereditary neuropathies of the motor and sensory systems. This gene was also identified as a p53 target gene and a differentiation-related, putative metastatic suppressor gene in human colon and prostate cancer. In this study, we show that the Rit42 protein is a microtubule-associated protein that localizes to the centrosomes and participates in the spindle checkpoint in a p53-dependent manner. When ectopically expressed and exposed to spindle inhibitors, Rit42 inhibited polyploidy in several p53-deficient tumor cell lines and increased the population of cells in mitotic arrest. Blocking endogenous Rit42 expression by small interfering RNA in normal human mammary epithelial cells resulted in the disappearance of astral microtubules, and dividing spindle fiber formation was rarely detected. Moreover, these cells underwent microtubule inhibitor-induced reduplication, leading to a polyploidy state. Our findings imply that Rit42 plays a role in the regulation of microtubule dynamics and the maintenance of euploidy.     

Microarray deacetylation maps determine genome-wide functions for yeast histone deacetylases

Yeast contains a family of five related histone deacetylases (HDACs) whose functions are known at few genes. Therefore, we used chromatin immunoprecipitation and intergenic microarrays to generate genome-wide HDAC enzyme activity maps. Rpd3 and Hda1 deacetylate mainly distinct promoters and gene classes where they are recruited largely by novel mechanisms. Hda1 also deacetylates subtelomeric domains containing normally repressed genes that are used instead for gluconeogenesis, growth on carbon sources other than glucose, and adverse growth conditions. These domains have certain features of heterochromatin but are distinct from subtelomeric heterochromatin repressed by the deacetylase Sir2. Finally, Hos1/Hos3 and Hos2 preferentially affect ribosomal DNA and ribosomal protein genes, respectively. Thus, acetylation microarrays uncover the "division of labor" for yeast histone deacetylases.     

Morpho-Physiological and Antioxidant Traits of Marigold cv. ‘Sparse Petal’ and ‘Compact Petal’ as Influenced by Irrigation Intervals

The effect of irrigation intervals was studied on physiological, morphological, and antioxidant traits of two marigold (Calendula officinalis L.) cultivars in Karaj, Iran, in a split-plot experiment based on a randomized complete block design with three replications. The experimental treatments included irrigation at three levels of I1 (irrigation interval of 3 days), I2 (irrigation interval of 5 days), and I3 (irrigation interval of 7 days) as the main plot and cultivar at two levels of V1 (cv. ‘sparse petal’) and V2 (cv. ‘compact petal’) as the sub-plot. The results based on the comparison of the means showed that the increase in irrigation interval from 3 to 7 days decreased the leaf area index, crop growth rate, relative growth rate, and net assimilation rate by 73.53, 85.76, 93.47, and 94.81%, respectively. It also decreased the flower yield, plant height, flower number, and leaf number by 71.92, 41.84, 99.31, and 58.67%, respectively. The interaction between irrigation and cultivar revealed that I3V1 had the highest total phenol content (3013.59 g gallic acid 100 g^?1 tissue) and antioxidant capacity (60.8%). It can be inferred that the treatment of I1 and cv. ‘compact petal’ give the best results for flower yield and physiological and morphological traits, and the treatment of I3 and both cultivars provide the best results for antioxidant traits in the climatic conditions of the Karaj region.

     

Role of p97 and syntaxin 5 in the assembly of transitional endoplasmic reticulum

Transitional endoplasmic reticulum (tER) consists of confluent rough and smooth endoplasmic reticulum (ER) domains. In a cell-free incubation system, low-density microsomes (1.17 g cc(-1)) isolated from rat liver homogenates reconstitute tER by Mg(2+)GTP- and Mg(2+)ATP-hydrolysis-dependent membrane fusion. The ATPases associated with different cellular activities protein p97 has been identified as the relevant ATPase. The ATP depletion by hexokinase or treatment with either N-ethylmaleimide or anti-p97 prevented assembly of the smooth ER domain of tER. High-salt washing of low-density microsomes inhibited assembly of the smooth ER domain of tER, whereas the readdition of purified p97 with associated p47 promoted reconstitution. The t-SNARE syntaxin 5 was observed within the smooth ER domain of tER, and antisyntaxin 5 abrogated formation of this same membrane compartment. Thus, p97 and syntaxin 5 regulate assembly of the smooth ER domain of tER and hence one of the earliest membrane differentiated components of the secretory pathway.     

Increasing donor age adversely impacts beneficial effects of bone marrow but not smooth muscle myocardial cell therapy

We evaluated the impact of donor age on the efficacy of myocardial cellular therapy for ischemic cardiomyopathy. Characteristics of smooth muscle cells (SMC), bone marrow stromal cells (MSCs), and skeletal muscle cells (SKMCs) from young, adult, and old rats were compared in vitro. Three weeks after coronary ligation, 3.5 million SMCs (n = 11) or MSCs (n = 9) from old syngenic rats or culture medium (n = 6) were injected into the ischemic region. Five weeks after implantation, cardiac function was assessed by echocardiography and the Langendorff apparatus. In the in vitro study, the numbers and proliferation of MSCs from fresh bone marrow and SKMCs from fresh tissue but not SMCs were markedly diminished in old animals (P < 0.05 both groups). SKMCs from old animals did not reach confluence. After treatment with 5-azacytidine (azacitidine), the myogenic potential of old MSCs was decreased compared with young MSCs. In the in vivo study, both SMC and MSC transplantation induced significant angiogenesis compared with media injections (P < 0.05 both groups). Transplantation of SMCs but not MSCs prevented scar thinning (P = 0.03) and improved ejection fraction and fractional shortening (P < 0.05). Load-independent indices of cardiac function in a Langendorff preparation confirmed improved function in the aged SMC group (P = 0.01) but not in the MSC group compared with the control group. In conclusion, donor age adversely impacts the efficacy of cellular therapy for myocardial regeneration and is cell-type dependent. SMCs from old donors retain their ability to improve cardiac function after implantation into ischemic myocardium.     

A unique epigenetic signature is associated with active DNA replication loci in human embryonic stem cells

The cellular epigenetic landscape changes as pluripotent stem cells differentiate to somatic cells or when differentiated cells transform to a cancerous state. These epigenetic changes are commonly correlated with differences in gene expression. Whether active DNA replication is also associated with distinct chromatin environments in these developmentally and phenotypically diverse cell types has not been known. Here, we used BrdU-seq to map active DNA replication loci in human embryonic stem cells (hESCs), normal primary fibroblasts and a cancer cell line, and correlated these maps to the epigenome. In all cell lines, the majority of BrdU peaks were enriched in euchromatin and at DNA repetitive elements, especially at microsatellite repeats, and coincided with previously determined replication origins. The most prominent BrdU peaks were shared between all cells but a sizable fraction of the peaks were specific to each cell type and associated with cell type-specific genes. Surprisingly, the BrdU peaks that were common to all cell lines were associated with H3K18ac, H3K56ac, and H4K20me1 histone marks only in hESCs but not in normal fibroblasts or cancer cells. Depletion of the histone acetyltransferases for H3K18 and H3K56 dramatically decreased the number and intensity of BrdU peaks in hESCs. Our data reveal a unique epigenetic signature that distinguishes active replication loci in hESCs from normal somatic or malignant cells.