Durable power of attorney for health care. Are we ready for it?

Health care professionals need to be well informed about advance directives for medical care in the event a patient becomes incapacitated. The Patient Self-Determination Act requires that all patients be advised of their options at the time of hospital admission. Hospitals and health care professionals will need to work together to plan for implementing this law. We surveyed 215 physicians, nurses, and social workers at a Veterans Affairs Medical Center about the California advance directive, the Durable Power of Attorney for Health Care. Attitudes were generally positive. All of the social workers had heard of the durable power of attorney directive, but 36% of physicians and nurses had never heard of it and an additional 20% had no experience with one. For respondents who had heard of the directive, the mean knowledge score was 6.35 of a possible 10 (5 predicted by chance). Respondents brought up the issue of durable power of attorney with patients before a crisis only 19% of the time and determined whether one had been signed for only 16% of older patients in hospital. The most commonly cited reasons for failure to discuss this with patients were lack of proper forms, pamphlets, or a place to refer a patient. Of those who had ever seen such a document in use, 42% were aware of a problem with it at some time. Whereas attitudes toward advance directives are positive, many physicians and nurses had little knowledge of the Durable Power of Attorney for Health Care and were poorly equipped to discuss it with patients. We encourage educating hospital staff to prepare for the enactment of the Patient Self-Determination Act. We also recommend that the concerns raised by professionals about the use of a durable power of attorney be addressed.     

Aeschynanthus hildebrandii Hemsl. ex Hook. f. (Gesneriaceae)—A new record for China

Aeschynanthus hildebrandii Hemsl. ex Hook. f. is reported as a new record for China.     

Importance of S. M. Razumovskií's theories for the vegetation science

Publication of S.M. Razumovsky collection works (including some unknown articles) shows his theoretical legacy for current vegetation science. Concepts of S.M. Razumovsky are in the frame of organismic paradigm. He believed that plant communities and associations are natural and continuum concept is only the result of methodical mistakes. Monoclimax (in the meaning of F. Clements) was considered by Razumovsky as the fundamental low of vegetation. Now these statements are very doubtful, but some of his ideas (succession systems, cenophyllous and cenofobous species, the principle and experience of vegetation regionalisation on the base of floristic criteria) are very useful for current vegetation science.     

Radiolabeled octreotide. What lessons for antibody-mediated targeting?

Octreotide is a synthetic analog of the peptide hormone somatostatin (SMS). A wide variety of tumors express enhanced numbers of SMS receptors, notably neuroendocrine tumors and lymphomas, but also some of the more common adenocarcinomas. Octreotide contains only eight amino acids, some of which are in the (D) configuration in order to enhance the stability of the molecule in vivo. Tyrosine and DTPA-containing analogs of octreotide have been synthesized and labeled with iodine-123 and indium-111, respectively, with the intention of targeting SMS receptor-containing tumors for diagnostic purposes. Both radiopharmaceuticals demonstrate a high sensitivity and specificity for these tumors, indicating a clinical role for these agents in management of these diseases. Lessons can be learned from the success of these agents when designing improved antibody-based molecules. Tumor uptake of radiolabeled octreotide is very rapid, occurring within minutes of administration. Blood clearance is also rapid, such that tumors are soon visible even in areas of high blood background. An interesting finding has been the differences between the pharmacokinetics of the iodinated and indium-labeled species. Although the majority of 123I-Tyr3-octreotide undergoes hepatobiliary excretion, 111In-DTPAPhe1-octreotide is eliminated predominantly by the kidneys. These results suggest that the smallest possible antibody-like tracers are likely to have advantages over native immunoglobulins and conventional Fab-like fragments.     

A direct solid‐phase assay specific for heavy metal toxicity. I. methodology

We have developed a direct toxicity assay for soils, sediments and sludges that is specific for heavy‐metal toxicity. In the assay, a β‐galactosidase‐producingstrain of Escherichia coll is mixed with the solids sample together with a small volume (1.0 ml/0.5 to 1.0 g of solids) of eluent Extraction of metals from the solids sample is not required. Controls run with the assay eliminate interference due to indigenous β‐ga‐lactosidase activity or interaction between the solid matrix and the chromaphore. Use of 0.1 M sodium nitrate as eluent was found to yield somewhat higher sensitivity to heavy metals in solid‐phase samples than MilliQ water. Application of the assay to a diverse array of soils, sludges, and sediments indicated that samples from industrial sites were generally more toxic than those from residential or commercial sites. Heavy‐metal toxicity was correlated with the copper and zinc content of solids samples, but toxicity varied considerably at the lower range of metal contents. The proposed solid‐phase assay should prove useful as a screening test for heavy‐metal toxicity in soils, sediments, and sludges. It can also help distinguish between heavy metals and organic chemicals as the cause of toxicity in solid‐phase samples.     

5′-C-Tosyloxyalkylnucleosides. Models for Oligonucleotide Coupling with Nucleophiles

Abstract

5′-C-substituted nucleosides with an hydroxyalkyl chain are synthesized. The stereochemistry of the new stereogenic center is defined. After introduction of a tosyl group, dimer models are prepared to evaluate the conjugation with amines used as nucleophiles.     

Direct or indirect? Graphical models for neural oscillators.

Univariate and bivariate time series analysis techniques have enabled new insights into neural processes. However, these techniques are not feasible to distinguish direct and indirect interrelations in multivariate systems. To this aim multivariate times series techniques are presented and investigated by means of simulated as well as physiological time series. Pitfalls and limitations of these techniques are discussed.