Rediscovering Chemical Gardens: Self-Assembling Cytocompatible Protein-Intercalated Silicate-Phosphate Sponge-Mimetic Tubules.

The classic chemical garden experiment is reconstructed to produce protein-intercalated silicate-phosphate tubules that resemble tubular sponges. The constructs were synthesized by seeding calcium chloride into a solution of sodium silicate-potassium phosphate and gelatin. Sponge-mimetic tubules were fabricated with varying percentages of gelatin (0-15% w/v), in diameters ranging from 200 μm to 2 mm, characterized morphologically and compositionally, functionalized with biomolecules for cell adhesion, and evaluated for cytocompatibility.

Neuroprotective role of taurine during aging.

Aging of the brain is characterized by several neurochemical modifications involving structural proteins, neurotransmitters, neuropeptides and related receptors. Alterations of neurochemical indices of synaptic function are indicators of age-related impairment of central functions, such as locomotion, memory and sensory performances. Several studies demonstrate that ionotropic GABA receptors, glutamate decarboxylase (GAD), and somatostatinergic subpopulations of GABAergic neurons are markedly decreased in experimental animal brains during aging.

Taurine's effects on the neuroendocrine functions of pancreatic β cells.

Taurine plays significant physiological roles, including those involved in neurotransmission. Taurine is a potent γ-aminobutyric acid (GABA) agonist and alters cellular events via GABA(A) receptors. Alternately, taurine is transported into cells via the high affinity taurine transporter (TauT), where it may also play a regulatory role.

The effects of chronic taurine supplementation on motor learning.

Taurine is one of the most abundant nonprotein amino acids shown to be essential for the development, survival, and growth of vertebrate neurons. We previously demonstrated that chronic taurine supplementation during neonatal development results in changes in the GABAergic system (El Idrissi, Neurosci Lett 436:19-22, 2008). The brains of mice chronically treated with taurine have decreased levels of GABA(A)β subunits and increased expression of GAD and GABA, which contributes to hyperexcitability.

Assimilation of elements and digestion in grass shrimp pre-exposed to dietary mercury.

Grass shrimp Palaemonetes pugio were fed mercury (Hg)-contaminated oligochaetes for 15 days and analyzed for Hg, cadmium (Cd), and carbon assimilation efficiencies (AE) as well as toxicological end points related to digestion. Disproportionate increases in stable Hg concentrations in shrimp did not appear to be related to partitioning to trophically available Hg in worms. Hg AE by pre-exposed shrimp reached a plateau (approximately 53 %), whereas Cd AE varied (approximately 40-60 %) in a manner that was not dose-dependent.

Carbon assimilation and digestive toxicity in naïve grass shrimp (Palaemonetes pugio) exposed to dietary cadmium.

Naïve grass shrimp Palaemonetes pugio were pulse-fed cadmium-contaminated meals containing carbon-14, fluorescent or near-infrared markers and analyzed for carbon assimilation efficiency, gut residence time, feces elimination rate, extracellular digestive protease activity or gut pH. Carbon assimilation efficiency (~83%), minimum gut residence time (~435 min) and proventriculus pH (~5.29 to ~6.

Neuroendocrine alterations in the fragile X mouse.

The expression of GABA(A) receptors in the fragile X mouse brain is significantly downregulated. We additionally found that the expression of somatostatin and voltage-sensitive calcium channels (VSCCs) is also reduced. GABA(A) and the VSCCs, through a synergistic interaction, perform a critical role in mediating activity-dependent developmental processes.

Digestive toxicity in grass shrimp collected along an impact gradient.

Ingested pollutants may elicit digestive toxicity following incorporation into consumer tissues. This post-assimilatory toxicity may include tissue damage influencing synthesis of digestive enzymes, gut transit time and absorption of nutrients as well as pollutants by the gut epithelium. This study investigated impacts of chronic field exposure on gut residence time (GRT), feces elimination rate (FER), extracellular digestive protease activities and gut pH in grass shrimp Palaemonetes pugio.

Neuro-endocrine basis for altered plasma glucose homeostasis in the Fragile X mouse.

Background: The fragile X mouse model shows an increase in seizure susceptibility, indicating an involvement of the GABAergic system via an alteration in cellular excitability. In the brain, we have previously described a reduction in GABAA receptor expression as a likely basis for this susceptibility. In the brains of fragile X mice, this reduction in receptor expression culminates with a concomitant increase in the expression of glutamic acid decarboxylase (GAD), the enzyme responsible for GABA synthesis.

Taurine regulation of short term synaptic plasticity in fragile X mice.

Background: Fragile X Syndrome is the most common known genetic cause of autism. The Fmr1-KO mouse, lacks the fragile X mental retardation protein (FMRP), and is used as a model of the syndrome. The core behavioral deficits of autism may be conceptualized either as excessive adherence to patterns as seen in repetitive actions and aberrant language, or as insensitivity to subtle but socially important changes in patterns.

Pharmacological characterization of GABAA receptors in taurine-fed mice.

Background: Taurine is one of the most abundant free amino acids especially in excitable tissues, with wide physiological actions. Chronic supplementation of taurine in drinking water to mice increases brain excitability mainly through alterations in the inhibitory GABAergic system. These changes include elevated expression level of glutamic acid decarboxylase (GAD) and increased levels of GABA.

Taurine regulates insulin release from pancreatic beta cell lines.

Background: Pancreatic beta-cells release insulin via an electrogenic response triggered by an increase in plasma glucose concentrations. The critical plasma glucose concentration has been determined to be approximately 3 mM, at which time both insulin and GABA are released from pancreatic beta-cells. Taurine, a beta-sulfonic acid, may be transported into cells to balance osmotic pressure.

A general methodology toward drug/dye incorporated living copolymer-protein hybrids: (NIRF dye-glucose) copolymer-avidin/BSA conjugates as prototypes.

Azide-terminated poly(tert-butyl acrylate) was synthesized via atom transfer radical polymerization (ATRP). Subsequent deprotection was performed to yield poly(acrylic acid) (PAA) possessing a reactive chain-end. A one-pot sequential amidation of the PAA with the amine derivatives of a near-infrared fluorescent dye (ADS832WS) and glucose produced NIRF dye-incorporated water-soluble copolymers.

Dibutylphthalate and Tween 80 alter ultrastructure in Candida albicans: implications for peroxisome proliferation.

Phthalates are ubiquitous environmental pollutants associated with endocrine disruption and peroxisome proliferation in experimental animals. In yeasts exposed to environmental chemicals, including phthalates, alterations in cell growth, cellular morphology, and H2O2 detoxification occur. Nutrient availability also influences diverse cellular processes.

Taurine supplementation and pancreatic remodeling.

Taurine is a semi-essential sulphur containing amino acid derived from methionine and cysteine metabolism. Taurine has several biological processes such as hypoglycemic action, antioxidation, and detoxification. In this study we evaluated the role of taurine in pancreatic islets development, since the endocrine pancreas undergoes significant modifications during neonatal life.

Functional implication of taurine in aging.

Age-related impairment of central functions is though to result from alterations of neurochemical indices of synaptic function. These neurochemical modifications involve structural proteins, neurotransmitters, neuropeptides and related receptors. Several studies demonstrated that GABA receptors, glutamic acid decarboxylase (GAD65&67), and different subpopulations of GABAergic neurons are markedly decreased in experimental animal brains during aging.

Synthesis of monofunctional curcumin derivatives, clicked curcumin dimer, and a PAMAM dendrimer curcumin conjugate for therapeutic applications.

Curcumin, the primary active ingredient in the spice turmeric, was converted to reactive monofunctional derivatives (carboxylic acid/azide/alkyne). The derivatives were employed to produce a 3 + 2 azide-alkyne "clicked" curcumin dimer and a poly(amidoamine) (PAMAM) dendrimer-curcumin conjugate. The monofunctional curcumin derivatives retain biological activity and are efficient for labeling and dissolving amyloid fibrils.