No major differences in perinatal and maternal outcomes between uninterrupted embryo culture in time-lapse system and conventional embryo culture.

STUDY QUESTION: Is embryo culture in a closed time-lapse system associated with any differences in perinatal and maternal outcomes in comparison to conventional culture and spontaneous conception? SUMMARY ANSWER: There were no significant differences between time-lapse and conventional embryo culture in preterm birth (PTB, <37 weeks), low birth weight (LBW, >2500 g) and hypertensive disorders of pregnancy for singleton deliveries, the primary outcomes of this study. WHAT IS KNOWN ALREADY: Evidence from prospective trials evaluating the safety of time-lapse incubation for clinical use show similar embryo development rates, implantation rates, and ongoing pregnancy and live birth rates when compared to conventional incubation. Few studies have investigated if uninterrupted culture can alter risks of adverse perinatal outcomes presently associated with IVF when compared to conventional culture and spontaneous conceptions. STUDY DESIGN, SIZE, DURATION: This study is a Swedish population-based retrospective registry study, including 7379 singleton deliveries after fresh embryo transfer between 2013 and 2018 from selected IVF clinics. Perinatal outcomes of singletons born from time-lapse-cultured embryos were compared to singletons from embryos cultured in conventional incubators and 71 300 singletons from spontaneous conceptions. Main perinatal outcomes included PTB and LBW. Main maternal outcomes included hypertensive disorders of pregnancy (pregnancy hypertension and preeclampsia). PARTICIPANTS/MATERIALS, SETTING, METHODS: From nine IVF clinics, 2683 singletons born after fresh embryo transfer in a time-lapse system were compared to 4696 singletons born after culture in a conventional incubator and 71 300 singletons born after spontaneous conception matched for year of birth, parity, and maternal age. Patient and treatment characteristics from IVF deliveries were cross-linked with the Swedish Medical Birth Register, Register of Birth Defects, National Patient Register and Statistics Sweden. Children born after sperm and oocyte donation cycles and after Preimplantation Genetic testing cycles were excluded. Odds ratio (OR) and adjusted OR were calculated, adjusting for relevant confounders. MAIN RESULTS AND THE ROLE OF CHANCE: In the adjusted analyses, no significant differences were found for risk of PTB (adjusted OR 1.11, 95% CI 0.87-1.41) and LBW (adjusted OR 0.86, 95% CI 0.66-1.14) or hypertensive disorders of pregnancy; preeclampsia and hypertension (adjusted OR 0.99, 95% CI 0.67-1.45 and adjusted OR 0.98, 95% CI 0.62-1.53, respectively) between time-lapse and conventional incubation systems. A significantly increased risk of PTB (adjusted OR 1.31, 95% CI 1.08-1.60) and LBW (adjusted OR 1.36, 95% CI 1.08-1.72) was found for singletons born after time-lapse incubation compared to singletons born after spontaneous conceptions. In addition, a lower risk for pregnancy hypertension (adjusted OR 0.72 95% CI 0.53-0.99) but no significant difference for preeclampsia (adjusted OR 0.87, 95% CI 0.68-1.12) was found compared to spontaneous conceptions. Subgroup analyses showed that some risks were related to the day of embryo transfer, with more adverse outcomes after blastocyst transfer in comparison to cleavage stage transfer. LIMITATIONS, REASONS FOR CAUTION: This study is retrospective in design and different clinical strategies may have been used to select specific patient groups for time-lapse versus conventional incubation. The number of patients is limited and larger datasets are required to obtain more precise estimates and adjust for possible effect of additional embryo culture variables. WIDER IMPLICATIONS OF THE FINDINGS: Embryo culture in time-lapse systems is not associated with major differences in perinatal and maternal outcomes, compared to conventional embryo culture, suggesting that this technology is an acceptable alternative for embryo incubation. STUDY FUNDING/COMPETING INTEREST(S): The study was financed by a research grant from Gedeon Richter. There are no conflicts of interest for all authors to declare. TRIAL REGISTRATION NUMBER: N/A.

Interplay of water and reactive elements in oxidation of alumina-forming alloys.

High-temperature alloys are crucial to many important technologies that underpin our civilization. All these materials rely on forming an external oxide layer (scale) for corrosion protection. Despite decades of research on oxide scale growth, many open questions remain, including the crucial role of the so-called reactive elements and water. Here, we reveal the hitherto unknown interplay between reactive elements and water during alumina scale growth, causing a metastable 'messy' nano-structured alumina layer to form. We propose that reactive-element-decorated, hydroxylated interfaces between alumina nanograins enable water to access an inner cathode in the bottom of the scale, at odds with the established scale growth scenario. As evidence, hydride-nanodomains and reactive element/hydrogen (deuterium) co-variation are observed in the alumina scale. The defect-rich alumina subsequently recrystallizes to form a protective scale. First-principles modelling is also performed to validate the RE effect. Our findings open up promising avenues in oxidation research and suggest ways to improve alloy properties.

Arginine deiminase in Staphylococcus epidermidis functions to augment biofilm maturation through pH homeostasis.

Allelic replacement mutants were constructed within arginine deiminase (arcA1 and arcA2) to assess the function of the arginine deiminase (ADI) pathway in organic acid resistance and biofilm formation of Staphylococcus epidermidis 1457. A growth-dependent acidification assay (pH ∼5.0 to ∼5.2) determined that strain 1457 devoid of arginine deiminase activity (1457 ΔADI) was significantly less viable than the wild type following depletion of glucose and in the presence of arginine. However, no difference in viability was noted for individual 1457 ΔarcA1 (native) or ΔarcA2 (arginine catabolic mobile element [ACME]-derived) mutants, suggesting that the native and ACME-derived ADIs are compensatory in S. epidermidis. Furthermore, flow cytometry and electron paramagnetic resonance spectroscopy results suggested that organic acid stress resulted in oxidative stress that could be partially rescued by the iron chelator dipyridyl. Collectively, these results suggest that formation of hydroxyl radicals is partially responsible for cell death via organic acid stress and that ADI-derived ammonia functions to counteract this acid stress. Finally, static biofilm assays determined that viability, ammonia synthesis, and pH were reduced in strain 1457 ΔADI following 120 h of growth in comparison to strain 1457 and the arcA1 and arcA2 single mutants. It is hypothesized that ammonia synthesis via the ADI pathway is important to reduce pH stress in specific microniches that contain high concentrations of organic acids.

Parascaris equorum in foals and in their environment on a Swedish stud farm, with notes on treatment failure of ivermectin.

Environmental contamination and the egg excretion pattern of the ascarid Parascaris equorum (Nematoda) was investigated in relation to anthelmintic treatment on a Swedish stud farm. Faecal samples from 15 foals, dewormed every 8th-week with a paste formulation of ivermectin at the standard dose rate of 0.2 mg/kg bodyweight, were collected at five sampling occasions between August and November 2006. In addition, soil samples were obtained from four paddocks used by these foals in November 2006. The number of eggs per gram (epg) was counted in both faeces and soil. Egg excretion started when the foals were 3-4 months, and reached the highest levels when they were approximately 5-month-old, and was then followed by a decline. Egg excretion seemed to be unaffected by ivermectin despite these foals were dewormed at regular intervals. In four out of five foals examined 10 days after treatment, epg actually increased. In contrast, when either fenbendazol or pyrantel embonate were used instead of ivermectin, treatments were effective. The number of eggs in soil was significantly higher in the permanent paddock compared to in the temporarily used soil paddock and in the summer paddocks.

Changes in natriuretic peptides, apelin and adrenomedullin after off-pump and on-pump coronary artery bypass surgery.

AIM: The authors have evaluated the postoperative changes of natriuretic peptides, apelin and adrenomedullin after off-pump (OPCAB) and on-pump coronary artery bypass surgery (CCAB) to assess the impact of these techniques on the myocardium. METHODS: Twenty-two patients underwent OPCAB and 24 patients underwent CCAB. Plasma levels of NT-proANP, NT-proBNP, apelin and adrenomedullin were measured preoperatively, and on the 1st, 3rd, and 5th postoperative day. RESULTS: Natriuretic peptides, apelin and adrenomedullin increased significantly postoperatively. Natriuretic peptides were markedly elevated on the fifth postoperative day. Apelin was still increasing, but adrenomedullin, although elevated, clearly decreased toward baseline levels on the fifth postoperative day. CCAB was associated with significantly higher postoperative cTnI, but levels of natriuretic peptides, adrenomedullin and apelin did not differ significantly after CCAB and OPCAB. cTnI, echocardiographic parameters, cardiac index, and degree of postoperative pericardial effusion did not correlate with levels of natriuretic peptides, apelin and adrenomedullin. Postoperative levels of natriuretic peptides were significantly associated with parameters of renal function, age, and extracardiac arteriopathy. The correlation between preoperative estimated glomerular filtration rate and natriuretic peptides increased along the study intervals (NT-proANP rho: -0.181, -0.350, -0.364, and -0.442; NT-proBNP rho: -0.112, -0.420, -0.405 and -0.550). Also adrenomedullin correlated with parameters of renal function. The postoperative levels of apelin were not associated with any variable. CONCLUSION: A marked, sustained and similar increase in these five markers of cardiac adaptation was detected after OPCAB and CCAB. The upregulation of these peptides should be further investigated to evaluate their potential beneficial/harmful impact on the outcome after coronary surgery.

Differential effects of lead exposure on components of verbal memory.

AIMS: To determine if verbal learning and memory requiring acquisition and retention of information is differentially affected by lead exposure. METHODS: The Rey Auditory Verbal Learning Test (RAVLT), a test of verbal learning and memory, was administered to 256 English speaking lead smelter workers who had a mean (SD) age of 41 (9.4) years and employment duration of 17 (8.1) years. Lead exposure variables, based on up to 25 years of prior blood lead data, included a mean (SD) current blood lead (PbB) of 28 (8.8) microg/dl, working lifetime time weighted average blood lead (TWA) of 39 (12.3) microg/dl, and working lifetime integrated blood lead index (IBL) of 728 (434.4) microg-y/dl. Associations of these chronic and recent lead exposure variables with measures from the RAVLT were modelled through multiple linear regressions after controlling for age and educational achievement. RESULTS: PbB was not associated with any of the RAVLT variables. However, TWA and IBL contributed significantly to the explanation of variance of measures of encoding/storage and retrieval but not to immediate memory span, attention, and learning. Grouping study participants by RAVLT performance according to three recognised clinical memory paradigms showed significantly higher TWA and IBL in the group with "generalised memory impairment" after adjusting for age and educational achievement. We examined recall mechanisms in each group by serial position in the word list and found stronger primacy (recall of words from the beginning of the list) in the "no impairment" and "retrieval difficulties" groups while the "generalised memory impairment" group had better performance on recency (recall of words from the end of the list). CONCLUSIONS: Lead exposure over years and not PbB interfered with the organisation and recall of previously learned verbal material. Chronic lead exposure affects encoding/storage and retrieval of verbal information.

Troglitazone effects on gene expression in human skeletal muscle of type II diabetes involve up-regulation of peroxisome proliferator-activated receptor-gamma.

Troglitazone, besides improving insulin action in insulin-resistant subjects, is also a specific ligand for the nuclear receptor peroxisome proliferator-activated receptor-gamma (PPARgamma). To determine whether troglitazone might enhance insulin action by stimulation of PPARgamma gene expression in muscle, total PPARgamma messenger RNA (mRNA), and protein were determined in skeletal muscle cultures from nondiabetic control and type II diabetic subjects before and after treatment of cultures with troglitazone (4 days +/- troglitazone, 11.5 microM). Troglitazone treatment increased PPARgamma mRNA levels up to 3-fold in muscle cultures from type II diabetics (277 +/- 63 to 630 +/- 100 x 10(3) copies/microg total RNA, P = 0.003) and in nondiabetic control subjects (200 +/- 42 to 490 +/- 81, P = 0.003). PPARgamma protein levels in both diabetic (4.7 +/- 1.6 to 13.6 +/- 3.0 AU/10 microg protein, P < 0.02) and nondiabetic cells (7.4 +/- 1.0 to 12.7 +/- 1.8, P < 0.05) were also upregulated by troglitazone treatment. Increased PPARgamma was associated with stimulation of human adipocyte lipid binding protein (ALBP) and muscle fatty acid binding protein (mFABP) mRNA, without change in the mRNA for glycerol-3-phosphate dehydrogenase, PPARdelta, myogenin, uncoupling protein-2, or sarcomeric alpha-actin protein. In summary, we showed that troglitazone markedly induces PPARgamma, ALBP, and mFABP mRNA abundance in muscle cultures from both nondiabetic and type II diabetic subjects. Increased expression of PPARgamma protein and other genes involved in glucose and lipid metabolism in skeletal muscle may account, in part, for the insulin sensitizing effects of troglitazone in type II diabetes.

Thalamic metabolic rate predicts EEG alpha power in healthy control subjects but not in depressed patients.

BACKGROUND: EEG alpha power has been demonstrated to be inversely related to mental activity and has subsequently been used as an indirect measure of brain activation. The hypothesis that the thalamus serves as a neuronal oscillator of alpha rhythms has been supported by studies in animals, but only minimally by studies in humans. METHODS: In the current study, PET-derived measures of regional glucose metabolism, EEG, and structural MRI were obtained from each participant to assess the relation between thalamic metabolic activity and alpha power in depressed patients and healthy controls. The thalamus was identified and drawn on each subject's MRI. The MRI was then co-registered to the corresponding PET scan and metabolic activity from the thalamus extracted. Thalamic activity was then correlated with a 30-min aggregated average of alpha EEG power. RESULTS: Robust inverse correlations were observed in the control data, indicating that greater thalamic metabolism is correlated with decreased alpha power. No relation was found in the depressed patient data. CONCLUSIONS: The results are discussed in the context of a possible abnormality in thalamocortical circuitry associated with depression.

Plasma carnitine and renal-carnitine clearance during pregnancy.

This study assessed the time course of decrease in plasma carnitine during pregnancy and compared the renal clearance of carnitine during late pregnancy with nonpregnant women. As early as the 8th wk of pregnancy, the mean (+/- SD) value of total plasma-carnitine concentration in 19 women was significantly decreased from 39.0 +/- 6.3 to 32.8 +/- 4.6 mumol/l and the values continued to fall to 17.3 mumol/l by the 36th wk. The pattern was due to a fall in free-carnitine level; acylcarnitine remained unchanged. In 12 other women examined during late pregnancy, the renal clearance of acylcarnitine was significantly higher than in nonpregnant women, 53.9 +/- 29.4 versus 13.3 +/- 3.0 ml/min, in contrast to free carnitine, 3.5 +/- 2.8 versus 2.8 +/- 1.9 ml/min. Urinary excretion of carnitine (expressed per mol creatinine) did not differ between the two groups. Pregnant women showed sustained excretion of carnitine in the presence of low plasma-carnitine concentrations.

Memory complaints in older adults. Fact or fiction?

Complaints of poor memory by patients may be an early symptom of a pathologic process like Alzheimer's disease. It is therefore important to determine if patients' complaints of memory impairments are an accurate reflection of real memory disturbance. The relationship between memory complaints (metamemory) and objective memory performance, mood, age, verbal intelligence, and sex was examined in a group of 199 healthy, community dwelling adults (39 to 89 years old). Memory complaints demonstrated a stronger association with depressed mood than with performance on memory tests. Increasing reports of depressive symptoms were associated with more overall memory complaints. Verbal intelligence, age, and sex also contributed to memory complaints. Patients with higher verbal intelligence reported fewer complaints and placed less emphasis on forgetting. Older individuals reported greater frequency of forgetting and greater frequency of using memory techniques. Specific types of memory complaints, seriousness of forgetting, and types of memory aids employed are also described. These results showed that self-rating of memory disturbance by older adults may be related more to depressed mood than to poor performance on memory tests.

Differential contribution of current and cumulative indices of lead dose to neuropsychological performance by age.

We examined measures of lead dose that reflect intensity of exposure and cumulative exposure for differential association with neuropsychological functional domains and with neuropsychological performance by age. Eighty active lead smelter workers assessed for verbal memory and visuomotoric skills had a mean (range) age of 44 (24-64) years, duration of employment of 20 (4-26) years, education of 8 (0-13) grades, current blood lead (B-Pb) of 26 microgPb dl(-1) (13-43), working lifetime weighted average blood lead (TWA) of 42 microgPb dl(-1) (17-57), working lifetime integrated blood lead (IBL) of 903 microgPb-yr dl(-1) (81-1,436) and bone lead (bone-Pb) of 41 microgPb (g bone mineral)(-1) (-12-90). Multiple linear regression after adjusting for age and education showed a significant amount of variance in verbal memory (Rey Auditory Verbal Learning Test and Verbal Paired Associates) explained only by measures of lead dose intensity, B-Pb, and TWA. Visuomotoric ability (Grooved Pegboard [GP] and Digit Symbol) had significant variance accounted for by measures of both lead dose intensity, TWA, and of cumulative lead dose, IBL, and bone-Pb. The relationship between bone-Pb and GP was curvilinear in older workers, with increasingly slower performance above a bone-Pb threshold of 20 microgPb (g bone mineral)(-1). Examination of age-related change in GP with exposure using IBL, a surrogate for cumulative lead dose in the brain, showed enhanced age-related change in older workers with high IBL. These findings suggest that the older nervous system provides a substrate more susceptible to the effects of chronic lead exposure.

A new oral slow release form of isosorbide dinitrate. Effect on the hemodynamics and exercise capacity of patients with angina.

To assess the bioavailability of a new oral and slow release form of isosorbide dinitrate (ISDN-SR), we evaluated 12 patients with confirmed coronary artery disease, chronic stable angina pectoris and abnormal maximal exercise tests (angina-limited and associated with greater than or equal to 0.1 mV ST displacement). Each patient was known to have an increased exercise time after 0.4 mg of sublingual nitroglycerin. Patient responses to exercise on the treadmill at two, four, six, and eight hours after the double-blind administration of 40 mg of ISDN-SR were compared to an identical placebo. It is concluded that 40 mg of this slow release form of isosorbide dinitrate is bioavailable for at least eight hours as demonstrated by significantly improved exercise capacity of the majority (64 percent) of angina patients in this study, each of whom demonstrated anginal limitation to exercise and favorable responses to 0.4 mg of sublingual nitroglycerin.

Seasonal, geographic and individual variation of okadaic acid content in cultivated mussels in Sweden.

In Western Europe the dinoflagellate toxin, okadaic acid (OA) has been the main cause of diarrheic shellfish poisoning (DSP). Chemical determination of OA in mussels by homogenization of the hepatopancreas, extraction, purification, reaction with 9-anthryldiazomethane (ADAM), HPLC-separation, and fluorometric quantification has been used for weekly monitoring of mussel growing farms and to control harvested mussels. Within a week, substantial rises (from 0.41 to 5.4 micrograms OA/g hepatopancreas) as well as great reductions (from 7.2 to 1.8 micrograms/g hepatopancreas) were recorded. The rapid rise implies that weekly sampling is not sufficient to ensure that mussels are free from toxic levels of OA. The rapid decrease reveals that efficient toxin clearance mechanisms exist in the mussels. Substantial OA clearance occurs also at low temperatures (1.4-3 degrees C). Within a mussel growing site the OA concentrations could differ considerably between adjacent mussels (0.63 and 4.2 micrograms OA/g hepatop.) and even more between mussels grown at different depths along the same rope (0.63 and 10 micrograms OA/g hepatop.). These data emphasize the importance of sampling in studies on DST in mussels. Great differences between the different mussel growing sites were also observed. These data have been discussed with respect to the spread of the toxin by the sea, and the possibilities of reducing the exposure of the mussels to the toxic algae.

Metabolic rate in the right amygdala predicts negative affect in depressed patients.

The role of the amygdala in major depression was investigated. Resting regional cerebral metabolic rate (rCMRglu) was measured with [18F]fluorodeoxyglucose positron emission tomography (PET) in two samples of subjects using two different PET cameras. The samples consisted of 10 and 17 medication-free depressives and 11 and 13 controls, respectively. Using coregistration of PET and magnetic resonance images, regions were individually delineated for the amygdala and thalamus, the latter of which was used as a control region. Within the depressed groups, right amygdalar rCMRglu was positively correlated with negative affect. Thalamic rCMRglu was not related to negative affect, and amygdalar rCMRglu accounted for a significant portion of variance in depressives' negative affect scores over and above the contribution of thalamic rCMRglu.

Differences in the glycosylation of recombinant and native human milk bile salt-stimulated lipase revealed by peptide mapping.

The milk of some mammals contains a bile salt-stimulated lipase (BSSL). Human milk BSSL is heavily glycosylated (30-40% carbohydrate) and present at a concentration of approximately 100-200 mg/l, thereby being one of the most abundant human whey proteins. BSSL has been shown to have an important role in the uptake of energy from human milk. The risk of HIV contamination has restricted the use of banked human milk for nutritional purposes. This has evoked an interest in the production of a recombinant form of the protein for supplementation of formula. We have produced BSSL in mouse C127 and hamster CHO cells, and used chromatographic methods for the characterization of the products. This study was focused on study of the glycosylation of the protein by using peptide mapping and isolation of glycosylated fragments. The results show how human BSSLs from different sources differ both in extent of glycosylation, in glycan heterogeneity, and in lectin binding.

Whiplash injuries in Finland: a prospective 1-year follow-up study.

OBJECTIVES: The aim of the study was to define how many whiplash injuries occur in Finland in traffic accidents and the degree of severity of these injuries using the whiplash-associated disorders (WAD) classification presented by the Quebec Task Force, and to define possible long-term health effects caused by whiplash injury as well as the duration of whiplash-associated sick-leaves. METHODS: This was a prospective one-year-follow-up study. Fourteen insurance companies paving compensations for traffic accidents in Finland sent the accident reports and medical certificates of all neck injuries attributable to traffic accidents to the research team. The material was collected from neck injuries that had occurred in traffic accidents during the year 1998. RESULTS: The majority of those suffering a whiplash injury were women. On the basis of the WAD classification, most whiplash injuries were mild, belonging to grades WAD I and II. At one year from the accident nearly 10% considered that their health had been impaired significantly as a result of their neck injury. Over 10% of those questioned had been on sick-leave for over a month but only 1.5% had been on sick-leave associated with the injury for more than 6 months. The most common symptom after one year was neck pain or neck pain combined with headache and symptoms in the upper extremities. No major changes related to the seasons of the year were found. CONCLUSIONS: The number of reported neck injuries in proportion to all traffic accidents involving physical injuries is small, even in proportion to rear-end collisions. In a considerable proportion of collision patients, whiplash injury does result in significant impairment which can last as long as a year after the accident. The WAD classification predicts the duration of work disability and the long-term health damage caused by the injury. Since the appearance of symptoms and the individual need for rehabilitation due to impaired functional capacity do not depend solely on the tissue damage and biomechanical forces involved in the collision, in the future it will be important to determine which factors are responsible for the differences in coping after a collision.

In-hospital resuscitation: association between ACLS training and survival to discharge.

CONTEXT: No data have been published on the relationship between advanced cardiac life support (ACLS) training of the individual who initiates resuscitation efforts and survival to discharge. OBJECTIVE: To determine whether patients whose arrests were discovered by nurses trained in ACLS had survival rates different from those discovered by nurses not trained in ACLS. DESIGN: Cohort case-comparison. SETTING: A 550-bed, tertiary care center in central Georgia. SUBJECTS: Patients whose cardiopulmonary arrest was discovered by a nurse who activated the in-hospital resuscitation mechanism. MAIN OUTCOME MEASURE: Patient survival to discharge. RESULTS: Initial rhythm was strongly related to survival to discharge and individually associated with 57% of the variability in survival. Nurse's training in advanced cardiac life support was also strongly related to survival and individually associated with 29% of the variability. Combining both the variables determined 62% of the variability in survival to discharge. Patients discovered by an ACLS-trained nurse (n=88) were about four times more likely to survive (33 survivors, 38%) than were patients, discovered by a nurse without training in ACLS (n=29, three survivors, 10%). CONCLUSION: Arrest discovery by nurses trained in ACLS is significantly and dramatically associated with higher survival-to-discharge rates.

Effects of habitual caffeine use and acute ingestion: testing a biobehavioral model.

A recently proposed model of the biobehavioral effects of caffeine suggests that acute ingestion impacts physiology and behavior differentially depending on the level of habitual usage of the drug. Acute ingestion and habitual usage are particularly expected to affect arousal and attentional processes. Subjects in the present study were preselected for high and low habitual caffeine use, given caffeine or a placebo, exposed to white noise or no white noise, and asked to perform on several tasks. Included were an arousal/habituation task (pure tones), reaction time, paired associates, anagrams, and vigilance. Electrodermal activity and performance were recorded. As predicted, virtually all effects were on the arousal/habituation and attentional (vigilance) tasks. Both acute ingestion and habitual use increased tonic EDA, and chronic use also reduced phasic responding, especially in the presence of a strong habituating stimulus. Both acute and habitual use also liberalized the vigilance response criterion, in that subjects risked more false alarms in order to attain more hits. In addition, habitual use increased sensitivity and reduced accuracy, and acute ingestion increased vigilance response time in the presence of white noise. Overall, the model was partially supported by these early results, though considerable further research is needed.

Syndromal versus contextualized personality assessment: differentiating environmental and dispositional determinants of boys' aggression.

Two studies examined how "syndromal" approaches to assessment confound differences between individuals in the person and situation variables that contribute to their behavior. In a field study, a widely used instrument was found to be sensitive to the base rates of boys' aggression but, as expected, did not discriminate between boys who were similar in their behavior base rates but different in their social environments and how they responded to them. A laboratory experiment replicated this finding and demonstrated that social observers discriminated between targets on the basis of their functional properties even though syndrome scores did not. The results clarify how syndromal methods can obscure situational factors, conflict with people's social knowledge, and reinforce the view that syndromes exist "in the individual" rather than in person-environment interactions. Implications for developing more contextually sensitive instruments are discussed.

Long-term outcome of surgery for thoracic outlet syndrome.

BACKGROUND: Thoracic outlet syndrome (TOS) is one of the most controversial symptom complexes in surgery today. Even the existence of TOS is questioned and where it seems to exist, the incidence varies from one country to another. Surgery is often considered the primary treatment; however, the frequency of good results after surgery varies from 24% to 100%, and in recent years the surgical approach has been questioned. PATIENTS AND METHODS: In this study 45 patients who had undergone surgery for TOS symptoms over a period of 21 years were examined by an independent clinician an average of 8 years after the operation. RESULTS: Forty-three percent of the performed operations were found to have been successful. Preoperative nocturnal and neck pain were more frequent in the unsuccessful group; no other preoperative characteristics had a predictive value. Preoperative radiographic and neurophysiologic examinations were also not predictive of the outcome. CONCLUSION: It is recommended that the feasibility of conservative therapeutic approaches should be evaluated before undertaking surgery for TOS symptoms.