alpha-cardiac actin (ACTC) binds to the band 3 (AE1) cardiac isoform

The band 3 protein is the major integral protein present in the erythrocyte membrane. Two tissue-specific isoforms are also expressed in kidney alpha intercalated cells and in cardiomyocytes. It has been suggested that the cardiac isoform predominantly mediates the anion exchange in cardiomyocytes, but the role of the cytoplasmic domain of the band 3 (CDB3) protein in the cardiac tissue is unknown. In order to characterize novel associations of the CDB3 in the cardiac tissue, we performed the two-hybrid assay, using a bait comprising the region from leu 258 to leu 311 of the erythrocyte band 3, which must also be present in the cardiac isoform. The assay revealed two clones containing the C-terminal region of the alpha-cardiac actin. Immunoprecipitation of whole rat heart using an anti-actin antibody, immunoblotted with anti-human band 3, showed that actin binds to band 3 which was confirmed in the reverse assay. The confocal microscopy showed band 3 in the intercalated discs. Thus, besides the in vivo physical interaction in the Saccharomyces cerevisiae cell, we demonstrated using immunopreciptation that there is a physical association of band 3 with alpha-cardiac actin in cardiomyocyte, and we suggest that the binding occur "in situ," in the intercalated disc, a site of cell-cell contact and attachment of the sarcomere to the plasma membrane.     

Production of pectinesterase and polygalacturonase by Aspergillus niger in submerged and solid state systems

Production of pectinesterase and polygalacturonase by Aspergillus niger was studied in submerged and solid-state fermentation systems. With pectin as a sole carbon source, pectinesterase and polygalacturonase production were four and six times higher respectively in a solid state system than in a submerged fermentation system and required a shorter time for enzyme production. The addition of glucose increased pectinesterase and polygalacturonase production in the solid state system but in submerged fermentation the production was markedly inhibited. A comparison of enzyme productivities showed that those determined for pectinesterase and polygalacturonase with pectin as a carbon source were three and five times higher by using the solid state rather than the submerged fermentation system. The productivities of the two enzymes were affected by glucose in both fermentation systems. The membranes of cells from the solid state fermentation showed increased levels of C18:1, C16:0 and C18:0 fatty acids. Differences in the regulation of enzyme synthesis by Aspergillus niger depended on the fermentation system, favoring the solid state over the submerged fermentation for pectinase production. Received 12 May 1997/ Accepted in revised form 19 September 1997     

Using the Fast Fourier Transform to Accelerate the Computational Search for RNA Conformational Switches

Using complex roots of unity and the Fast Fourier Transform, we design a new thermodynamics-based algorithm, FFTbor, that computes the Boltzmann probability that secondary structures differ by base pairs from an arbitrary initial structure of a given RNA sequence. The algorithm, which runs in quartic time and quadratic space , is used to determine the correlation between kinetic folding speed and the ruggedness of the energy landscape, and to predict the location of riboswitch expression platform candidates. A web server is available at http://bioinformatics.bc.edu/clotelab/FFTbor/.     

Toxicity of hexachlorobenzene in Meriones unguiculatus: effects on thyroid and liver

The effect of in vivo administered hexachlorobenzene (HCB) on liver and thyroid was studied on Meriones unguiculatus. HCB (1.6, 4, and 16 mg/kg of body weight) has been administered orally to meriones for 30 days. At the end of the experiment, the body weight of the animals did not show significant change. However, the higher dose of HCB treatment led to a pronounced hepatic hypertrophy comparatively to controls. Histological observations revealed many cytomorphological alterations. Cellular necrosis, periportal, and centrolobular vein congestion and cytoplasmic vacuolisation were noted and correlated with the administered doses of HCB. The higher dose of HCB induced modifications in the activities of hepatic transaminases and on thyroid hormones levels: ALAT activity level was more pronounced in males (170+/-24.7 U/l vs. 52.66+/-8.29 U/l in controls) than in females (120+/-12.47 U/l vs. 56+/-5 U/l in controls). However, ASAT activity increased significantly only in females (259+/-29 U/l vs. 244.66+/-18 U/l in controls). Plasma total triiodothyronine (TT3) and total thyroxine (TT4) levels seemed to be sex-dependent in intoxicated animals, since TT4 decreased significantly in males (21.95+/-7.46 nmol/l vs. 40.59+/-1.08 nmol/l in controls) and TT3 in females (1.42+/-0.11 nmol/l vs. 3.96+/-0.48 nmol/l in controls).     

Parthenocarpy of watermelon cultivars induced by γ-irradiation

We found that diploid seedless watermelon can be produced by pollination with partially functional pollen, which was irradiated with γ-rays at the doses of 600 and 800 Gy. The diploid seedless fruits were almost similar to normal fruits in development from pollination to maturity. The number of empty seeds in the diploid seedless fruits varied among the cultivars used. Seedless watermelon cultivars revealed a significant increase in total sugar and carotenoids (lycopene and gb-carotene) contents. The pollen tubes of the pollen subjected to γ-radiation penetrated normally into the synergid, and sperm cells were discharged. Subsequently, the egg nucleus and sperm nucleus became attached to each other in the egg cell and a globular embryo was formed. However, the embryo failed to differentiate the tissues and degenerated. It is suggested that seedless watermelon fruits induced by γ-rays are characterized by increasing yield and better quality due to higher carotenoid and total sugar contents and fruit weight. In some cultivars, there is a tendency in decreasing the thickness of rind.     

Same species,different population dynamics: Spatio-temporal differences of Undaria pinnatifida (Ochrophyta,Phaeophyceae) in the intertidal of North Patagonia,Argentina

Population dynamics can be influenced by physical and biological factors, particularly in stressful environments. Introduced species usually have great physiological plasticity, resulting in populations with different traits. Undaria pinnatifida, a macroalga originally described from northeast Asia, was introduced in Northern Patagonia, Argentina (San Matías Gulf) around 2010. To describe the spatio-temporal variability in population structure and morphometry of U. pinnatifida, we conducted monthly field samplings for 2 years at the intertidal area of two contrasting sites in the San Matías Gulf. Individuals of U. pinnatifida were classified by developmental stage, and their morpho-gravimetric variables were measured. In both intertidal sites juveniles were found in higher proportion during austral autumn and grew and matured during the autumn-winter months (from May onwards), and individuals senesced during early austral summer (December and January). Conversely, density and biomass were largely different between sites, and individuals showed slight morphological variability between sites. Environmental (e.g., nutrient concentration, available substrate) and biological factors (e.g., facilitation, competition) may explain the observed differences. Since there is not a macroalga with U. pinnatifida morphometrical characteristics in the intertidal environments of San Matías Gulf, studying this recent introduction gives us a better understanding of its potential ecological effects.     

Interaction between TGF-β1 (869C/T) polymorphism and biochemical risk factor for prediction of disease progression in rheumatoid arthritis

Objectives

Rheumatoid arthritis (RA) is a chronic inflammatory disease. Transforming growth factor-β1 (TGF-β1) may be a promising candidate gene for susceptibility and severity in RA. We aimed to determine whether TGF-β1 polymorphism is associated with susceptibility to RA and progression of joint destruction, as well as to identify the interaction between TGF-β1 polymorphism and biochemical risk factor.

Methods

A total of 160 RA patients and 168 healthy unrelated controls were tested for the TGF-β1 (869C/T) polymorphism using polymerase chain reaction.

Results

The TGF-β1 T allele was associated with susceptibility to RA. Within the RA group, TGF-β1 T allele carriers had a significant increased risk to develop osteoporosis (OR = 4.4, 95% CI = - 2. 4 – 8.1, P < 0.001), as well as more likely to develop bone erosion (OR = 1.7, 95% CI = 0. 99–2.7, P = 0. 034). Better prediction was achieved when the TGF-β1 TT genotype was used in combination with either elevated, rheumatoid factor (RF) or C-reactive protein (CRP) (OR = 6.8, 3.7 respectively). Also, they increased the risk to develop bone erosion in patients with rheumatoid arthritis (OR = 3.3, 9.8, P = 0.017, 0.001 respectively).

Conclusion

Our results suggest that TGF-β1 TT genotype may determine the development of osteoporosis and bone erosion in RA. Also, our results points to a synergism between TGF-β1 TT genotype and elevated serum RF or elevated CRP that lead to the development of osteoporosis and bone erosion in patients with rheumatoid arthritis.     

Effects of double ligation of Stensen's duct on the rabbit parotid gland

Salivary gland duct ligation is an alternative to gland excision for treating sialorrhea or reducing salivary gland size prior to tumor excision. Duct ligation also is used as an approach to study salivary gland aging, regeneration, radiotherapy, sialolithiasis and sialadenitis. Reports conflict about the contribution of each salivary cell population to gland size reduction after ductal ligation. Certain cell populations, especially acini, reportedly undergo atrophy, apoptosis and proliferation during reduction of gland size. Acini also have been reported to de-differentiate into ducts. These contradictory results have been attributed to different animal or salivary gland models, or to methods of ligation. We report here a bilateral double ligature technique for rabbit parotid glands with histologic observations at 1, 7, 14, 30, 60 days after ligation. A large battery of special stains and immunohistochemical procedures was employed to define the cell populations. Four stages with overlapping features were observed that led to progressive shutdown of gland activities: 1) marked atrophy of the acinar cells occurred by 14 days, 2) response to and removal of the secretory material trapped in the acinar and ductal lumens mainly between 30 and 60 days, 3) reduction in the number of parenchymal (mostly acinar) cells by apoptosis that occurred mainly between 14–30 days, and 4) maintenance of steady-state at 60 days with a low rate of fluid, protein, and glycoprotein secretion, which greatly decreased the number of leukocytes engaged in the removal of the luminal contents. The main post- ligation characteristics were dilation of ductal and acinar lumens, massive transient infiltration of mostly heterophils (rabbit polymorphonuclear leukocytes), acinar atrophy, and apoptosis of both acinar and ductal cells. Proliferation was uncommon except in the larger ducts. By 30 days, the distribution of myoepithelial cells had spread from exclusively investing the intercalated ducts pre-ligation to surrounding a majority of the residual duct-like structures, many of which clearly were atrophic acini. Thus, both atrophy and apoptosis made major contributions to the post-ligation reduction in gland size. Structures also occurred with both ductal and acinar markers that suggested acini differentiating into ducts. Overall, the reaction to duct ligation proceeded at a considerably slower pace in the rabbit parotid glands than has been reported for the salivary glands of the rat.     

Different natural biomasses for lead cation removal

It is believed that some wastes play an important role on the pollution prevention. In this paper, three different natural biomasses were investigated as biosorbent. Salsola green plant which grown at Jubail (industrial area) in KSA, it is phyto remediation plant. Salsola is metal hyper accumulation plant, it adsorbed (23.5, 25.7 mg lead per gram stem or leaf) from soil. Also it can be reused as ion exchanger for pb²⁺ from solution. Shrimp shell’s used for extraction of chitosan in laboratory with degree of substitution 81%. Chitosan and crosslinked carboxymethyl chitosan were investigated for pb²⁺ adsorption and compared with crosslinked carboxymethyl corn cob. The adsorption experiments demonstrated that the three biomasses have high adsorption capacity for pb²⁺, good reusability and stability for three cycles.     

Stability-enhanced Hot-melt Extruded Amorphous Solid Dispersions via Combinations of Soluplus? and HPMCAS-HF

The aim of this study was to evaluate a novel combination of Soluplus® and hypromellose acetate succinate (HPMCAS-HF) polymers for solubility enhancement as well as enhanced physicochemical stability of the produced amorphous solid dispersions. This was accomplished by converting the poorly water-soluble crystalline form of carbamazepine into a more soluble amorphous form within the polymeric blends. Carbamazepine (CBZ), a Biopharmaceutics Classification System class II active pharmaceutical ingredient (API) with multiple polymorphs, was utilized as a model drug. Hot-melt extrusion (HME) processing was used to prepare solid dispersions utilizing blends of polymers. Drug loading showed a significant effect on the dissolution rate of CBZ in all of the tested ratios of Soluplus® and HPMCAS-HF. CBZ was completely miscible in the polymeric blends of Soluplus® and HPMCAS-HF up to 40% drug loading. The extrudates were characterized by differential scanning calorimetry (DSC), X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy and dissolution studies. DSC and XRD data confirmed the formation of amorphous solid dispersions of CBZ in the polymeric blends of Soluplus® and HPMCAS-HF. Drug loading and release of CBZ was increased with Soluplus® (when used as the primary matrix polymer) when formulations contained Soluplus® with 7–21% (w/w) HPMCAS-HF. In addition, this blend of polymers was found to be physically and chemically stable at 40°C, 75% RH over 12 months without any dissolution rate changes.KEY WORDS: carbamazepine, hot-melt extrusion, HPMCAS-HF, Soluplus®, stability