Comparative Assessment of Response to Cadmium in Heavy Metal-Tolerant Shrubs Cultured In Vitro.

Two species of Pb-adapted shrubs, Alyssum montanum and Daphne jasminea, were evaluated in vitro for their tolerance to elevated concentrations of cadmium. Shoot cultures were treated with 0.5, 2.5, and 5.0 µM CdCl2 for 16 weeks and analyzed for their organogenic response, biomass accretion, pigment content, and macronutrient status. Cadmium accumulation and its root-to-shoot translocation were also determined. In both species, rooted microplantlets, suitable for acclimatization, were obtained in the presence of Cd applied as selection agent. In A. montanum, low and moderate dose of Cd stimulated multiplication, rooting, and biomass production. Growth tolerance index (GTI) in Cd-treated shoots ranged from 120 to 215%, while in the roots 51-202%. In turn, in Cd-treated D. jasminea proliferation and rooting were inhibited, and GTI for shoots decreased with increasing doses of Cd. However, roots exposed to Cd had higher biomass accretion. Both species accumulated Cd in developed organs, and its content increased with increasing CdCl2 dose. Interestingly, D. jasminea accumulated higher amounts of Cd in the roots than A. montanum and immobilized this metal in the root system. On the contrary, A. montanum translocated some part of accumulated Cd to the shoots, but with low efficiency. In the presence of Cd, A. montanum maintained macronutrient homeostasis and synthesized higher amounts of phytosynthetic pigments in the shoots. D. jasminea accumulated root biomass, immobilized Cd, and restricted its translocation at the expense of nutrient balance. Considering remediation potential, A. montanum could be exploited in phytoextraction, while D. jasminea in phytostabilization of polluted substrate.

Coagulation protein function. II. Influence of thiols upon acetaldehyde effects.

It has been reported that prolonged prothrombin time may be a result of the interaction of acetaldehyde (AcH) with clotting proteins to form alkylated inactive products. The current investigation focuses on the influence of L-cysteine (CysH), DL-homocysteine (HC), D-penicillamine, N-acetyl-L-cysteine (NAC), L-serine and L-alanine at 0.01 M concentrations, lactalbumin hydrolysate (2 mg/ml), and 1.0 mM dithiothreitol (DTT) on clotting time as well as their interaction with AcH. The sulfhydryl amino acids, as well as DTT prolonged clotting upon preincubation with plasma. Cysteine and NAC, upon addition to plasma prior to the addition of AcH, exhibited a prolongation of clotting time compared to that of AcH alone. On sequential addition of serine, alanine, or lactalbumin hydrolysate to plasma followed by the addition of acetaldehyde, a prolongation of clotting time comparable to that of AcH alone was exhibited. When HC and penicillamine were added to plasma prior to the addition of AcH, a prolonged clotting time was observed, which was significantly less than that of AcH alone. Premixing of serine, alanine, and lactalbumin hydrolysate with AcH for 20 min prior to addition to the plasma reduced the effectiveness of AcH in prolonging clotting time as compared to successive additions of the amino acid and AcH. Since CysH and penicillamine have been reported to form cyclic adducts with AcH, it is suggested that a similar possibility exists for penicillamine and for HC. The reversible cyclic adduct formation reported for CysH may explain why cysteine did not lower the prolonged clotting time induced by AcH.(ABSTRACT TRUNCATED AT 250 WORDS)

Acetaldehyde alters coagulation protein function.

Acetaldehyde is the first metabolite of ethanol and has the potential to react with proteins and alter their function. This study evaluated the function of clotting proteins that had been preincubated with acetaldehyde as compared to those incubated with buffer or ethanol as controls. Thrombin, fibrinogen, thromboplastin, or whole plasma were preincubated with 1.8-447 mM acetaldehyde, 1.7-429 mM ethanol, or buffer for varying time periods prior to use in a clotting assay. Clot formation was measured with an automatic fibrometer. Acetaldehyde prolonged the clotting time but ethanol did not. These experiments indicate that circulating acetaldehyde would have the potential to react with proteins of the clotting system and alter their function. Therefore, it is possible that not all of the abnormalities in coagulation in alcohol abusers result from inadequate hepatic synthesis. Perhaps some of the deranged coagulation may be the result of the interaction of acetaldehyde with coagulation proteins.

Superheated drop detector for determination of neutron dose equivalent to patients undergoing high-energy x-ray and electron radiotherapy.

The superheated drop detector (SDD) consists of thousands of superheated drops dispersed in a small vial of gel, which vaporize upon exposure to high LET radiation, thereby providing a directly observable indication of neutron dose. This detector possesses high sensitivity to neutrons and insensitivity to high-energy photons and electrons, making it suitable for the determination of neutron dose equivalent rates around high-energy photon and electron radiotherapy beams. In the present work, the SDD was used to measure the neutron dose equivalent in and around the radiotherapy beams produced by a 32-MeV linear accelerator. For both x-ray and electron beams, the neutron dose profiles were observed to follow the photon/electron radiotherapy beam profiles. For 25-MV x rays, the neutron dose equivalent per photon dose on the central axis increased by a factor of about 3 as field size increased from 5 x 5 to 30 x 30 cm. However, the neutron dose equivalent rate at 50 cm off-axis in the patient plane was essentially independent of field size. The neutron dose equivalent per electron dose was essentially zero for electron beams with energies below 15 MeV, but increased rapidly above 15 MeV. For 25-MeV electrons, neutron dose equivalent on the central axis was about 1/5 that for 25-MV x rays. Analogous to the data for 25-MV x rays, the neutron dose equivalent rate on the central axis of a 25-MeV electron beam exhibited a similar field size dependence and outside the beam it was essentially independent of field size.(ABSTRACT TRUNCATED AT 250 WORDS)

The action approach. Integrating a community's needs into the corporate planning process.

With the city of Detroit in turmoil, Mercy Hospitals and Health Services of Detroit (MHHSD) is trying to assimilate the community's unmet needs into the corporate planning process. Through the Community Assessment of Human Needs process, MHHSD identified the needs of the poor in three of Michigan's most impoverished areas. On the basis of these findings, MHHSD collaborated with the Poverty and Social Reform Institute to form the East Side Initiative, a community planning effort to address the community's unmet needs. An advisory group was established to oversee the East Side Initiative's planning process. The East Side Initiative participants met as one group and in smaller groups to focus on specific needs in the areas of healthcare, crime prevention, substance abuse, education, housing, economic development, and family (social) supports. The proposed action plans of each small group have received approval. In the second phase of the East Side Initiative participants will attempt to obtain the necessary resources to implement the groups' proposed actions.

Treatment decisions in a skilled-nursing facility: discordance with nurses' preferences.

Hospitalization transfers from a skilled-nursing facility were studied. A hierarchically arranged questionnaire on acute medical deterioration and treatment aggressiveness was used to study the degree of discordance between the transfers actually made and the preferences of nursing home head nurses. According to the nurses, 37 per cent of the patients involved should not have been hospitalized even under the most compelling circumstances; however, 76 per cent of this subgroup had in fact been hospitalized under physician's orders. The nurses would have refrained from instituting any new treatment in 14 per cent of the cases, all of which involved chronic neurological impairments; 36 per cent of this subgroup had nevertheless been hospitalized in the 12 months prior to the study.