Anti-calcification of bovine pericardium for bioprosthetic heart valves after surface modification with hyaluronic acid derivatives

Surface modification of glutaraldehyde fixed bovine pericardium (GFBP) was successfully carried out with hyaluronic acid (HA) derivatives. At first, HA was chemically modified with adipic dihydrazide (ADH) to introduce hydrazide functional group into the carboxyl group of HA backbone. Then, GFBP was surface modified by grafting HA-ADH to the free aldehyde groups on the tissue and the subsequent HA-ADH hydrogel coating. HA-ADH hydrogels could be prepared through selective crosslinking at low pH between hydrazide groups of HA-ADH and crosslinkers containing succinimmidyl moieties with minimized protein denaturation. When HA-ADH hydrogels were prepared at low pH of 4.8 in the presence of erythropoietin (EPO) as a model protein, EPO release was continued up to 85% of total amount of loaded EPO for 4 days. To the contrary, only 30% of EPO was released from HA-ADH hydrogels prepared at pH=7.4, which might be due to the denaturation of EPO during the crosslinking reaction. Because the carboxyl groups on the glucuronic acid residues are recognition sites for HA degradation by hyaluronidase, the HA-ADH hydrogels degraded more slowly than HA hydrogels prepared by the crosslinking reaction of divinyl sulfone with hydroxyl groups of HA. Following a two-week subcutaneous implantation in osteopontin-null mice, clinically significant levels of calcification were observed for the positive controls without any surface modification. However, the calcification of surface modified GFBP with HA-ADH and HA-ADH hydrogels was drastically reduced by more than 85% of the positive controls. The anti-calcification effect of HA surface modification was also confirmed by microscopic analysis of explan ted tissue after staining with Alizarin Red S for calcium, which followed the trend as observed with calcium quantification.     

Foregut Mesenchyme Contributes Cells to Islets during Pancreatic Development in a 3-Dimensional Avian Model

Current interest in the potential use of pancreatic stem-cells in the treatment of insulin dependent diabetes mellitus has led to increased research into normal pancreatic development. Pancreatic organogenesis involves branching morphogenesis of undifferentiated epithelium within surrounding mesenchyme. Current understanding is that the pancreatic islets develop exclusively from the epithelium of the embryonic buds. However, a cellular contribution to islets by mesenchyme has not been conclusively excluded. We present evidence that the mesenchyme of both the dorsal pancreatic bud and stomach rudiment make a substantial contribution of cells to islets during development in a three-dimensional avian model. These data suggest that mesenchyme can be a source not only of signals but also of cells for the definitive epithelia, making pancreatic organogenesis more akin to that of the kidney than to other endodermal organs. This raises the possibility for the use of mesenchymal cells as stem-or progenitor-cells for islet transplantation.Key Words: islets, stem-cells, development, epithelium, mesenchyme, pancreas, stomach, chick-quail, 3-dimensional, endocrine     

Neurological Response to cART vs. cART plus Integrase Inhibitor and CCR5 Antagonist Initiated during Acute HIV

Objective

To compare central nervous system (CNS) outcomes in participants treated during acute HIV infection with standard combination antiretroviral therapy (cART) vs. cART plus integrase inhibitor and CCR5 antagonist (cART+).

Design

24-week randomized open-label prospective evaluation.

Method

Participants were evaluated then randomized to initiate cART (efavirenz, tenofovir, and either emtricitabine or lamivudine) vs. cART+ (cART plus raltegravir and maraviroc) during acute HIV and re-evaluated at 4, 12 and 24 weeks. We examined plasma and CSF cytokines, HIV RNA levels, neurological and neuropsychological findings, and brain MRS across groups and compared to healthy controls.

Results

At baseline, 62 participants were in Fiebig stages I-V. Randomized groups were similar for mean age (27 vs. 25, p = 0.137), gender (each 94% male), plasma log₁₀ HIV RNA (5.4 vs. 5.6, p = 0.382), CSF log₁₀ HIV RNA (2.35 vs. 3.31, p = 0.561), and estimated duration of HIV (18 vs. 17 days, p = 0.546). Randomized arms did not differ at 24 weeks by any CNS outcome. Combining arms, all measures concurrent with antiretroviral treatment improved, for example, neuropsychological testing (mean NPZ-4 of -0.408 vs. 0.245, p<0.001) and inflammatory markers by MRS (e.g. mean frontal white matter (FWM) choline of 2.92 vs. 2.84, p = 0.045) at baseline and week 24, respectively. Plasma neopterin (p<0.001) and interferon gamma-induced protein 10 (IP-10) (p = 0.007) remained elevated in participants compared to controls but no statistically significant differences were seen in CSF cytokines compared to controls, despite individual variability among the HIV-infected group.

Conclusions

A 24-week course of cART+ improved CNS related outcomes, but was not associated with measurable differences compared to standard cART.     

Molecular differentiation of Chenopodium album complex and some related species using ISSR profiles and ITS sequences

The present study was undertaken to understand the genetic differentiation and relationships in various components of C. album complex, C. giganteum and some related species using inter simple sequence repeats (ISSR) profiles and internal transcribed spacer (ITS) sequences. The relationships based on UPGMA dendrograms have shown the heterogenous nature of C. album complex. The 2x taxa while showing close relation among themselves are sharply segregated from 4x and 6x taxa belonging to C. album and C. giganteum. Among the three cytotypes from North Indian plains the 4x shows greater similarity to 6x than to 2x which is corroborated by the karyotypic studies. Furthermore, the 6x C. album and C. giganteum accessions of American and European origin are clearly segregated from those of Indian origin which may show their separate origin. Other related species show relationships according to their taxonomic position. The present study based on ISSR profiles and ITS sequences has therefore been very useful in explaining the relationships between various components of C. album complex and related species. However, more work needs to be done using different CpDNA loci to define correct species boundary of the taxa under C. album complex from Himalayas and North Indian Plains.     

The melanosomal protein PMEL17 as a target for antibody drug conjugate therapy in melanoma

Melanocytes uniquely express specialized genes required for pigment formation, some of which are maintained following their transformation to melanoma. Here we exploit this property to selectively target melanoma with an antibody drug conjugate (ADC) specific to PMEL17, the product of the SILV pigment-forming gene. We describe new PMEL17 antibodies that detect the endogenous protein. These antibodies help define the secretory fate of PMEL17 and demonstrate its utility as an ADC target. Although newly synthesized PMEL17 is ultimately routed to the melanosome, we find substantial amounts accessible to our antibodies at the cell surface that undergo internalization and routing to a LAMP1-enriched, lysosome-related organelle. Accordingly, an ADC reactive with PMEL17 exhibits target-dependent tumor cell killing in vitro and in vivo.     

Nuclear DNA amounts in 112 species of tropical hardwoods -- new estimates

The 4C DNA values of 112 species, belonging to 37 families have a range from 0.83 pg (Bixa orellana) to 15.54 pg (Thryallis angustifolia), showing a 18.72-fold variation. The genome size varies from 0.21 pg (Bixa orellana) to 3.32 (Thespesia populnea), with a 15.8-fold difference. The Bombacaceae has the minimum range (1.08-fold) of variation, while the maximum (5.0-fold) is shown by the Fabaceae. The Boraginaceae, Lauraceae, Malpighiaceae, and Malvaceae generally have higher 4C DNA values of > 10 pg, while the Bixaceae, Caricaceae, Oxalidaceae, and Santalaceae have lower values of < 2.0 pg. These data add further to our knowledge on variation in DNA amount in tropical hardwoods.     

Jasmonic acid-induced tolerance to root-knot nematodes in tomato plants through altered photosynthetic and antioxidative defense mechanisms

Plant parasitic nematodes cause severe damage to cultivated crops globally. Management of nematode population is a major concern as chemicals used as nematicides have negative impact on the environment. Natural plant products can be safely used for the control of nematodes. Among various plant metabolites, plant hormones play an essential role in developmental and physiological processes and also assist the plants to encounter stressful conditions. Keeping this in mind, the present study was designed to evaluate the effect of jasmonic acid (JA) on the growth, pigments, polyphenols, antioxidants, osmolytes, and organic acids under nematode infection in tomato seedlings. It was observed that nematode inoculation reduced the growth of seedlings. Treatment with JA improved root growth (32.79%), total chlorophylls (71.51%), xanthophylls (94.63%), anthocyanins (37.5%), and flavonoids content (21.11%) when compared to inoculated seedlings alone. The JA application enhanced the total antioxidant capacity (lipid- and water-soluble antioxidants) by 38.23 and 34.37%, respectively, in comparison to infected seedlings. Confocal studies revealed that there was higher accumulation of glutathione in hormone-treated seedlings under nematode infection. Treatment with JA increased total polyphenols content (74.56%) in comparison to nematode-infested seedlings. JA-treated seedlings also enhanced osmolyte and organic acid contents under nematode stress. Overall, treatment with JA improved growth, enhanced pigment levels, modulated antioxidant content, and enhanced osmolyte and organic acid content in nematode-infected seedlings.     

Procathepsin D secreted by HaCaT keratinocyte cells - A novel regulator of keratinocyte growth

Procathepsin D (pCD), the precursor form of lysosomal aspartic protease, is overexpressed and secreted by various carcinomas. The fact that secreted pCD plays an essential role in progression of cancer has been established. In this study, we describe substantial secretion of pCD by the human keratinocyte cell line HaCaT, under serum-free conditions. Moreover, exogenous addition of purified pCD enhanced the proliferation of HaCaT cells. The proliferative effect of pCD was inhibited by a monoclonal antibody against the activation peptide (AP) of pCD. Treatment of HaCaT cells with pCD or AP led to the secretion of a set of cytokines that might promote the growth of cells in a paracrine manner. The role of secreted pCD and its mechanism of action were studied in a scratch wound model and the presence of pCD and AP enhanced regeneration, while this effect was reversed by the addition of anti-AP antibody. Expression and secretion of pCD was upregulated in HaCaT cells exposed to various stress conditions. Taken together, our results strongly suggest that the secretion of pCD is not only linked to cancer cells but also plays a role in normal physiological conditions like wound healing and tissue remodeling.     

Structure-activity relationship studies of flavonoids as potent inhibitors of human platelet 12-hLO, reticulocyte 15-hLO-1, and prostate epithelial 15-hLO-2

Human lipoxygenase (hLO) isozymes have been implicated in a number of disease states and have attracted much attention with respect to their inhibition. One class of inhibitors, the flavonoids, have been shown to be potent lipoxygenase inhibitors but their study has been restricted to those compounds found in nature, which have limited structural variability. We have therefore carried out a comprehensive study to determine the structural requirements for flavonoid potency and selectivity against platelet 12-hLO, reticulocyte 15-hLO-1, and prostate epithelial 15-hLO-2. We conclude from this study that catechols are essential for high potency, that isoflavones and isoflavonones tend to select against 12-hLO, that isoflavons tend to select against 15-hLO-1, but few flavonoids target 15-hLO-2.