Response of bean to some heavy metals in sewage water.

Seed germination and early growth of bean (Phaseolus vulgaris) seedlings were significantly reduced when irrigated with a mixture of Cu, Zn, Cd and Pb at concentrations of sewage water. Leaf content of photosynthetic pigments, carbohydrates, nucleic acids and total nitrogen also decreased. Cd and Pb significantly inhibited the activity of alpha and beta-amylases and protease enzymes during germination. Treatment of the mixture solution by precipitation, rice residue or EDTA decreased its retarding effect. The effect of precipitation was more pronounced. Whilst the lower concentration of Cu and Zn stimulated germination, growth and metabolism of bean seedling, the higher concentrations showed inhibitory effects. Even at very low concentrations of Cd and Pb germination, growth and metabolism of bean significantly decreased. Precipitation treatment alleviated the adverse effects of higher concentrations of Zn, Cu, Cd and Pb. Whilst rice residue and EDTA treatments slightly enhanced germination of seeds treated with high concentrations of Zn and Cu, they did not affect germination of seeds treated with Cd or Pb.

Alterations in nitrogen metabolites after putrescine treatment in alfalfa under drought stress.

Alfalfa (Medicago sativa, Siwa 1) seeds were subjected to drought stress during germination by using polyethylene glycol (PEG 4000) for studying the changes in some enzyme activities involved in nitrogen metabolism and the content of nitrogenous compounds during the first four days of growth after putrescine (Put) treatment. Decreasing the external water potential reduced activities of glutamate-pyruvate transferase (GPT), glutamate-oxaloacetate transferase (GOT) and RNase. Some free amino acids such as proline and glycine increased, while alanine and aspartic acid decreased. Nucleic acids content also decreased. Polyamines e.g., spermidine (Spd) and spermine (Spm) increased at the water potential -0.4 MPa. Put treatment increased activities of GOT, GPT and RNase. Furthermore, Put treatment increased nucleic acids content and the endogenous polyamines under drought stress. Drought stress was imposed during seedling stage by decreasing soil moisture content. GOT, GPT and RNase activities increased in leaves of alfalfa seedlings under drought stress. Soluble nitrogenous compounds accumulated under drought stress, while nucleic acids content decreased. Except glutamic acid, all free amino acids detected increased under drought stress. Put treatment decreased activities of GOT, GPT and RNase, as well as reduced the accumulation of the total soluble nitrogenous compounds, but increased DNA, RNA and protein contents.

Cytoprotection by fructose and other ketohexoses during bile salt-induced apoptosis of hepatocytes.

Toxic bile salts cause hepatocyte necrosis at high concentrations and apoptosis at lower concentrations. Although fructose prevents bile salt-induced necrosis, the effect of fructose on bile salt-induced apoptosis is unclear. Our aim was to determine if fructose also protects against bile salt-induced apoptosis. Fructose inhibited glycochenodeoxycholate (GCDC)-induced apoptosis in a concentration-dependent manner with a maximum inhibition of 72% +/- 10% at 10 mmol/L. First, we determined if fructose inhibited apoptosis by decreasing adenosine triphosphate (ATP) and intracellular pH (pHi). Although fructose decreased ATP to <25% of basal values, oligomycin (an ATP synthase inhibitor) did not inhibit apoptosis despite decreasing ATP to similar values. Fructose (10 mmol/L) decreased intracellular pH (pHi) by 0.2 U. However, extracellular acidification (pH 6.8), which decreased hepatocyte pHi 0.35 U and is known to inhibit necrosis, actually potentiated apoptosis 1.6-fold. Fructose cytoprotection also could not be explained by induction of bcl-2 transcription or metal chelation. Because we could not attribute fructose cytoprotection to metabolic effects, alterations in the expression of bcl-2, or metal chelation, we next determined if the poorly metabolized ketohexoses, tagatose and sorbose, also inhibited apoptosis; unexpectedly, both ketohexoses inhibited apoptosis. Because bile salt-induced apoptosis and necrosis are inhibited by fructose, these data suggest that similar processes initiate bile salt-induced hepatocyte necrosis and apoptosis. In contrast, acidosis, which inhibits necrosis, potentiates apoptosis. Thus, ketohexose-sensitive pathways appear to initiate both bile salt-induced cell apoptosis and necrosis, whereas dissimilar, pH-sensitive, effector mechanisms execute these two different cell death processes.

Neurologic deficits restored after elective posterior fossa decompression.

Arnold Chiari malformation is a condition in which the contents of the posterior fossa are herniated below the level of the foramen magnum, and it occurs in three basic forms. Patients with this condition frequently have obstructive hydrocephalus which requires a ventriculo-peritoneal shunt. This article describes the case of a infant female patient with Arnold Chiari Type I, who suffered an episode of acute hydrocephalus and neurologic deterioration after ventriculo-peritoneal shunt malformation. A shunt revision did not reverse her neurologic deficits, so a posterior fossa decompression was performed which did improve her condition.