Heat shock protein induction and induced thermal tolerance are independent in adult salamanders

Ectothermic vertebrates become thermally tolerant (heat hardened) after exposure to heat shock. Eukaryotic cells show a similar response. Cellular thermal tolerance is correlated with the induction of heat shock proteins (hsps). We have investigated the relationship between heat hardening in salamanders and the induction of hsps in the tissues of these organisms. Although the synthesis of hsps can be induced in these animals by sublethal heat shocks, conditions required for hsp induction and heat hardening often do not coincide. We conclude that induced thermal tolerance in adult salamanders is independent of hsp induction in their tissues.     

Detecting coevolution without phylogenetic trees? Tree-ignorant metrics of coevolution perform as well as tree-aware metrics

Background  

Identifying coevolving positions in protein sequences has myriad applications, ranging from understanding and predicting the structure of single molecules to generating proteome-wide predictions of interactions. Algorithms for detecting coevolving positions can be classified into two categories: tree-aware, which incorporate knowledge of phylogeny, and tree-ignorant, which do not. Tree-ignorant methods are frequently orders of magnitude faster, but are widely held to be insufficiently accurate because of a confounding of shared ancestry with coevolution. We conjectured that by using a null distribution that appropriately controls for the shared-ancestry signal, tree-ignorant methods would exhibit equivalent statistical power to tree-aware methods. Using a novel t-test transformation of coevolution metrics, we systematically compared four tree-aware and five tree-ignorant coevolution algorithms, applying them to myoglobin and myosin. We further considered the influence of sequence recoding using reduced-state amino acid alphabets, a common tactic employed in coevolutionary analyses to improve both statistical and computational performance.     

Detention of British citizens as hostages in the Gulf--health,psychological, and family consequences.

OBJECTIVE--To describe the physical, psychological, and family consequences of the detention of British subjects as hostages in Kuwait or Iraq, or both, after the invasion of Kuwait on 2 August 1990 and to investigate the relation between types of trauma experienced and these reactions. DESIGN--Postal questionnaire. SUBJECTS--381 respondents. RESULTS--Many health, social, and psychological sequelae were identified. Problems with present finance, accommodation, and work are important causes of distress. Many hostages coped well and gained self esteem. CONCLUSIONS--A minority of respondents require further support and treatment. Expatriates in risk areas should retain assets in their home country.     

Brain death and organ donation in a neurosurgical unit: audit of recent practice.

OBJECTIVE--To assess the potential for increasing the yield of donors by comparing the current pattern of brain death and organ donation in a neurosurgical unit with that reported in 1981 and with a recent national audit. DESIGN--Retrospective review of all deaths for 1986, 1987, and 1988 and prospective data for 1989. SETTING--A regional neurosurgical unit serving 2.7 million population. RESULTS--Of 553 deaths, 35% (191) patients died while on a ventilator and 17% (92) after discontinuation of ventilation. Medical contraindications to donation were found in 23% (32) of 141 patients tested for brain death, in 38% (19) of 50 patients who died while being ventilated who were not tested, and in 12% (11) of 92 patients no longer being ventilated. Consent for donation was sought in 88% (96) of 109 medically suitable brain dead patients and granted in 70% (67) of these. Half those with permission for multiorgan donation had only the kidneys removed. CONCLUSIONS--More organs may be lost owing to transplant team logistics than by failure to seek consent from relatives of brain dead patients. The estimated size of the pool of potential donors depends on what types of patients might be considered. Ensuring that all who die while being ventilated are tested for brain death and considering the potential for donation before withdrawing ventilation could yield more donors. Ventilating more patients who are hopelessly brain damaged to secure more donors raises ethical and economic issues.