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The purpose of this prospective study was to (1) evaluate the impact of retirement, (2) monitor the change in adjustment across time, and (3) identify the resources predictive of short- and long-term adjustment in retirement. A sample of 117 male retirees was assessed on indices of physical and psychological health, perceived control, retirement satisfaction, and life satisfaction at 2-4 months preretirement, 1 year post-, and 6-7 years postretirement. The results provided support for a positive impact of retirement, as retirees evidenced increases in well-being during the first year. There was also evidence of a retirement adjustment process, in that aspects of well-being (i.e., psychological health) changed from short- to long-term retirement. Finally, physical health, income, and voluntary retirement status predicted short-term adjustment, while internal locus of control was an additional resource for long-term adjustment. Changes in resources over time also differentially predicted short- and long-term adjustment (e.g., an increase in internal locus of control predicted an increase in activity satisfaction at 1 year but not at 6-7 years postretirement). A LTHOUGH retirement has received extensive study, the •**• nature of the impact of retirement and the resources important for a successful adjustment in retirement remain unclear. The length of time in retirement may be one factor that accounts for the inconsistency in results pertaining to the impact of retirement in particular (Jonsson, 1993). For example, studies have reported the existence of a negative association of well-being with time in retirement (Bosse, Aldwin, Levenson, Spiro, & Mroczek, 1993; Conner, Dorfman, & Tompkins, 1985; Knesek, 1992). However, the process of retirement adjustment may be more complex, reflecting specific patterns of change in a retiree's well-being at different points in time (Atchley, 1976). Atchley's stage model of retirement has received some support in recent studies (Bosse, Aldwin, Levenson, & Workman-Daniels, 1991; Ekerdt,. Bosse, & Levkoff, 1985; Richardson & Kilty, 1991; The"riault, 1994). There is also indication that the predictors of well-being or potential resources for a successful adjustment differ depending on the time postretirement (Bosse et al., 1991; Cherry, Zarit, & Krauss, 1984; Romsa, Bondy, & Blenman, 1985). The present research involves a prospective, longitudinal assessment of the retiree's well-being from 2-4 months preretirement to 1 year post- and 6-7 years postretirement. This study was designed to address the effects of time on the impact and process of retirement as well as on the importance of specific resources for a successful adjustment.

International audience; Elevated hydrostatic pressure was used to probe conformational changes of Aquifex aeolicus dihydroorotase (DHO), which catalyzes the third step in de novo pyrimidine biosynthesis. The isolated protein, a 45-kDa monomer, lacks catalytic activity but becomes active upon formation of a dodecameric complex with aspartate transcarbamoylase (ATC). X-ray crystallographic studies of the isolated DHO and of the complex showed that association induces several major conformational changes in the DHO structure. In the isolated DHO, a flexible loop occludes the active site blocking the access of substrates. The loop is mostly disordered but is tethered to the active site region by several electrostatic and hydrogen bonds. This loop becomes ordered and is displaced from the active site upon formation of DHO-ATC complex. The application of pressure to the complex causes its time-dependent dissociation and the loss of both DHO and ATC activities. Pressure induced irreversible dissociation of the obligate ATC trimer, and as a consequence the DHO is also inactivated. However, moderate hydrostatic pressure applied to the isolated DHO subunit mimics the complex formation and reversibly activates the isolated subunit in the absence of ATC, suggesting that the loop has been displaced from the active site. This effect of pressure is explained by the negative volume change associated with the disruption of ionic interactions and exposure of ionized amino acids to the solvent (electrostriction). The interpretation that the loop is relocated by pressure was validated by site-directed mutagenesis and by inhibition by small peptides that mimic the loop residues.

FLASH (FLICE-associated huge protein or CASP8AP2) is a large multifunctional protein that is involved in many cellular processes associated with cell death and survival. It has been reported to promote apoptosis, but we show here that depletion of FLASH in HT1080 cells by siRNA interference can also accelerate the process. As shown previously, depletion of FLASH halts growth by down-regulating histone biosynthesis and arrests the cell cycle in S-phase. FLASH knockdown followed by stimulating the cells with Fas ligand or anti-Fas antibodies was found to be associated with a more rapid cleavage of PARP, accelerated activation of caspase-8 and the executioner caspase-3 and rapid progression to cellular disintegration. As is the case for most anti-apoptotic proteins, FLASH was degraded soon after the onset of apoptosis. Depletion of FLASH also resulted in the reduced intracellular levels of the anti-apoptotic proteins, MCL-1 and the short isoform of cFLIP. FLASH knockdown in HT1080 mutant cells defective in p53 did not significantly accelerate Fas mediated apoptosis indicating that the effect was dependent on functional p53. Collectively, these results suggest that under some circumstances, FLASH suppresses apoptosis.

The results of liver transplantation are now well established in terms of graft and patient survival, but there is surprisingly little data on the quality of life attained. The authors mailed questionnaires to 32 consecutive adult liver recipients to assess their quality of life. Thirty-one patients (14 males, 17 females) with a mean age of 37 years (range 16 to 55), responded (97%). The mean time since transplantation was 19 months (range three to 50). Eighty percent of the respondents functioned at normal or near normal levels as measured by the Karnofsky Performance Index. Sixty-five per cent (20 patients) indicated they were currently able to live and function as they did before they became ill with liver disease. The respondents' scores were similar to normative scores on all of the following measures: life satisfaction, well being, and general affect (Campbell); and material well being, personal growth, marital relations, family relations and friendships (Evans). It is concluded that liver transplantation restores physical, mental and social well being in most patients with endstage liver disease.

This study compares the digestibility of a series of lupin and soybean protein products when fed to either rainbow trout or Atlantic salmon. The test ingredients in the study, from one of two key grain resources (lupins: Lupinus angustifolius and soybeans), represented various levels of processing of each grain in order to increase the protein content of the meals. A reference ingredient of enzymatically hydrolyzed casein (EHC) was also included in the study. The rainbow trout (266±18 g) were housed in freshwater tanks (250 l, salinity

Pyrococcus abyssi, a hyperthermophilic archaeon found in the vicinity of deep-sea hydrothermal vents, grows optimally at temperatures around 100 degrees C. Carbamoyl phosphate synthetase (CPSase) from this organism was cloned and sequenced. The active 34-kDa recombinant protein was overexpressed in Escherichia coli when the host cells were cotransformed with a plasmid encoding tRNA synthetases for low-frequency Escherichia coli codons. Sequence homology suggests that the tertiary structure of P. abyssi CPSase, resembling its counterpart in Pyrococcus furiosus, is closely related to the catabolic carbamate kinases and is very different from the larger mesophilic CPSases. P. furiosus CPSase and carbamate kinase form carbamoyl phosphate by phosphorylating carbamate produced spontaneously in solution from ammonia and bicarbonate. In contrast, P. abyssi CPSase has intrinsic bicarbonate-dependent ATPase activity, suggesting that the enzyme can catalyze the phosphorylation of the isosteric substrates carbamate and bicarbonate.

The temperature induced melting transition of a self-complementary DNA strand covalently attached at the 5' end to the surface of a gold interdigitated microelectrode (GIME) was monitored in a novel, label-free, manner. The structural state of the hairpin was assessed by measuring four different electronic properties of the GIME (capacitance, impedance, dissipation factor and phase angle) as a function of temperature from 25 degrees C to 80 degrees C. Consistent changes in all four electronic properties of the GIME were observed over this temperature range, and attributed to the transition of the attached single-stranded DNA (ssDNA) from an intramolecular, folded hairpin structure to a melted ssDNA. The melting curve of the self-complementary single strand was also measured in solution using differential scanning calorimetry (DSC) and UV absorbance spectroscopy. Temperature dependent electronic measurements on the surface and absorbance versus temperature values measured in solution experiments were analyzed assuming a two-state process. The model analysis provided estimates of the thermodynamic transition parameters of the hairpin on the surface. Two-state analyses of optical melting data and DSC measurements provided evaluations of the thermodynamic transition parameters of the hairpin in solution. Comparison of surface and solution measurements provided quantitative evaluation of the effect of the surface on the thermodynamics of the melting transition of the DNA hairpin.

The allosteric enzyme aspartate transcarbamoylase (EC 2.1.3.2) was previously shown to consist of two functionally distinct types of polypeptide chains. X-ray diffraction and chemical studies showed that there are six copies of both catalytic (C) and regulatory (R) chains, and that the intact molecular complex (C 6 R 6 ) has D 3 symmetry. Organomercurials react preferentially with the four thiol groups on each R chain, dissociating the molecular complex. We show that 2-chloromercuri-4-nitrophenol reacts specifically and rapidly with the single C-chain thiol, which is believed to be near the catalytic site. This reaction inactivates the enzyme in solution and does not dissociate the molecular complex. Spectrophotometric titration and mercury analysis indicates that six molecules of this mercurial are firmly bound to the enzyme (R 6 C 6 ), and crystallographic studies establish that only six sites, related by D 3 symmetry, are modified. The known low reactivity of this C-chain thiol with other sulfhydryl reagents, the unusual structural requirements in the reaction with 2-chloromercuri-4-nitrophenol, and the spectral properties of the resulting derivative provide insight into the environment of this thiol. Probably, at least one positively charged group of the enzyme is nearby, and the environment of this thiol is at least partially hydrophobic.