Dopamine release in ventral striatum of pathological gamblers losing money

OBJECTIVE

To investigate dopaminergic neurotransmission in relation to monetary reward and punishment in pathological gambling. Pathological gamblers (PG) often continue gambling despite losses, known as 'chasing one's losses'. We therefore hypothesized that losing money would be associated with increased dopamine release in the ventral striatum of PG compared with healthy controls (HC).

METHOD

We used Positron Emission Tomography (PET) with [(11)C]raclopride to measure dopamine release in the ventral striatum of 16 PG and 15 HC playing the Iowa Gambling Task (IGT).

RESULTS

PG who lost money had significantly increased dopamine release in the left ventral striatum compared with HC. PG and HC who won money did not differ in dopamine release.

CONCLUSION

Our findings suggest a dopaminergic basis of monetary losses in pathological gambling, which might explain loss-chasing behavior. The findings may have implications for the understanding of dopamine dysfunctions and impaired decision-making in pathological gambling and substance-related addictions.

Secondhand smoke exposure in Alaskan households with children

INTRODUCTION

Secondhand smoke (SHS) exposure causes premature death and disease in children and non-smoking adults; the home is the primary source of SHS exposure. The aim of this study was to assess variance in the prevalence of children's SHS exposure in Alaskan households with an adult smoker according to rurality, race/ethnicity, income and education, household age composition, marital status, amount smoked each day, and beliefs in SHS health consequences.

METHOD

Telephone interviews were conducted between 2004 and 2007 on a population-based random sample of 1119 Alaskan adult smokers with children living in the household.

RESULTS

Respondents living with children over 5 years of age reported a significantly (p <0.05) higher prevalence of home SHS exposure, compared with those living with younger children. Respondents 40 years and older reported significantly more exposure than others. Alaska Native smokers reported significantly lower SHS exposure in their homes than those of other races, as did those living in very rural areas. Respondents' heavier smoking was significantly associated with more SHS exposure. The sub-population of adults living without other adults was approximately 1.5 times more likely to report SHS exposure than those living with other adults. As expected, having a no-smoking rule in the home greatly lowered the risk of SHS exposure in the home.

CONCLUSIONS

Although most smokers with children believed that SHS is harmful, some need to convert those beliefs into actions. The results from this study suggest that those with school-aged children, and moderate to heavy smokers should be targeted for intervention, given their high prevalence of home SHS exposure. Future work should examine reasons for low exposure levels among Alaska Native people to inform programmatic efforts in other communities.

Change in teachers' ratings of attention problems and subsequent change in academic achievement: a prospective analysis

BACKGROUND

Recent research has documented a link between attention problems at school entry and later academic achievement. Little is known about the association of change in attention problems during the early school years with subsequent change in academic achievement.

METHOD

A community-based cohort was followed up and assessed for attention problems at ages 6 and 11 (Teacher Report Form; TRF) and for academic achievement in math and reading at ages 11 and 17 (Woodcock-Johnson Psycho-Educational Battery). Complete data were available on 590 children (72% of the initial sample). Ordinary least squares regressions were used to estimate change in academic achievement from age 11 to age 17 in relation to change in TRF-attention problems from age 6 to age 11. Children's IQ and family factors were statistically controlled.

RESULTS

Change in teachers' ratings of attention problems from age 6 to age 11 was negatively associated with change in math and reading from age 11 to age 17, controlling for children's IQ and family factors. Externalizing problems had no significant association with change in math or reading, when added to the multivariable model.

CONCLUSIONS

Increases in teacher-rated attention problems from age 6 to age 11 were followed by declines in academic achievement from age 11 to age 17; decreases were followed by gains. The results underscore the need for research on the course of attention problems, the testing of interventions to address children's early attention problems and the evaluation of their effects on subsequent academic achievement.

Probing unfolded acoustic phonons with X rays

Ultrafast laser excitation of an InGaAs/InAlAs superlattice (SL) creates coherent folded acoustic phonons that subsequently leak into the bulk (InP) substrate. Upon transmission, the phonons become "unfolded" into bulk modes and acquire a wave vector much larger than that of the light. We show that time-resolved x-ray diffraction is sensitive to this large-wave vector excitation in the substrate. Comparison with dynamical diffraction simulations of propagating strain supports our interpretation.

Robust population management under uncertainty for structured population models

Structured population models are increasingly used in decision making, but typically have many entries that are unknown or highly uncertain. We present an approach for the systematic analysis of the effect of uncertainties on long-term population growth or decay. Many decisions for threatened and endangered species are made with poor or no information. We can still make decisions under these circumstances in a manner that is highly defensible, even without making assumptions about the distribution of uncertainty, or limiting ourselves to discussions of single, infinitesimally small changes in the parameters. Suppose that the model (determined by the data) for the population in question predicts long-term growth. Our goal is to determine how uncertain the data can be before the model loses this property. Some uncertainties will maintain long-term growth, and some will lead to long-term decay. The uncertainties are typically structured, and can be described by several parameters. We show how to determine which parameters maintain long-term growth. We illustrate the advantages of the method by applying it to a Peregrine Falcon population. The U.S. Fish and Wildlife Service recently decided to allow minimal harvesting of Peregrine Falcons after their recent removal from the Endangered Species List. Based on published demographic rates, we find that an asymptotic growth rate lambda > 1 is guaranteed with 5% harvest rate up to 3% error in adult survival if no two-year-olds breed, and up to 11% error if all two-year-olds breed. If a population growth rate of 3% or greater is desired, the acceptable error in adult survival decreases to between 1% and 6% depending of the proportion of two-year-olds that breed. These results clearly show the interactions between uncertainties in different parameters, and suggest that a harvest decision at this stage may be premature without solid data on adult survival and the frequency of breeding by young adults.

pT1 SUBSTAGING IN RENAL CELL CARCINOMA: VALIDATION OF THE 2002 TNM STAGING MODIFICATION OF MALIGNANT RENAL EPITHELIAL TUMORS

PURPOSE

Tumor size has been used as one of the criteria to stratify renal cell carcinoma (RCC) into different pathological stages (pT). The recent 2002 UICC/TNM classification of malignant epithelial renal tumors is modified to substratify pT1 RCC into pT1a (less than 4.0 cm) and pT1b (greater than 4.0 but less than 7.0 cm). In this study we ascertained if this stage modification has prognostic relevance.

MATERIALS AND METHODS

A total of 259 consecutive radical nephrectomy specimens of organ confined RCC from 1970 to 1997 at 1 institution, including 153 of conventional RCC (CRCC), 71 of papillary RCC, 28 of chromophobe RCC, 1 of collecting duct carcinoma and 6 of RCC not otherwise specified, with a mean clinical followup of 7.5 years (median 6.4) were included in the study.

RESULTS

There were 115 pT1a (44.4%), 95 pT1b (36.7%) and 49 pT2 tumors (18.9%). Disease recurrences (DR) and disease specific death occurred in 2 (1.7%) and 0 cases (0%) of pT1a, 7 (7.3%) and 5 (5.3%) of pT1b, and 16 (32.6%) and 12 (24.5%) of pT2. DR for pT1b was higher compared with pT1a (all histological subtypes RR 3.68), although this difference was not statistically significant (p = 0.106). If only CRCCs were analyzed, DR in the pT1b group was statistically higher compared with pT1a (RR 8.54, p = 0.047). Disease specific survival in pT1a could not be evaluated because no deaths occurred in this subgroup. DR and disease specific survival were significantly different between pT1b and pT2 tumors for all histological subtypes (RR 5.51, p = 0.001 and 5.49, p = 0.001) and for the CRCC subtype (RR 5.50, p = 0.001 and 5.18, p = 0.005, respectively). Using size as a continuous variable the logarithmic change in tumor size was a significant predictor of DR (RR 8.82, p = 0.001). All statistical analyses were adjusted for age and sex.

CONCLUSIONS

Substaging RCC into pT1a and pT1b yields prognostically important information, validating the 2002 TNM modification for malignant renal epithelial malignancies. The substratification of pT1 is particularly useful in tumors with CRCC histology.

First-generation linkage map of the warningly colored butterfly Heliconius erato

We report the first genetic linkage map of Heliconius erato, a species that shows remarkable variation in its warningly colored wing patterns. We use crosses between H. erato and its sister species, H. himera, to place two major color pattern genes, D and Cr, on a linkage map containing AFLP, allozyme, microsatellite and single-copy nuclear loci. We identified all 21 linkage groups in an initial genetic screen of 22 progeny from an F1 female x male H. himera family. Of the 229 markers, 87 used to identify linkage groups were also informative in 35 progeny from a sibling backcross (H. himera female x F1 male). With these, and an additional 33 markers informative in the second family, we constructed recombinational maps for 19 of the 21 linkage groups. These maps varied in length from 18.1 to 431.1 centimorgans (cM) and yielded an estimated total length of 2400 cM. The average distance between markers was 23 cM, and eight of the 19 linkage groups, including the sex chromosome (Z) and the chromosome containing the Cr locus, contained two or more codominant anchor loci. Of the three potential candidate genes mapped here, Cubitus interruptus (Ci), Decapentaplegic (Dpp) and Wingless (Wg), only Ci was linked, although loosely, to a known Heliconius color pattern locus. This work is an important first step for constructing a denser genetic map of the H. erato color pattern radiation and for a comparative genomic study of the architecture of mimicry in Heliconius butterflies.

Tranexamic acid decreases external blood loss but not hidden blood loss in total knee replacement

BACKGROUND

Total knee arthroplasty (TKA) is often carried out using a tourniquet and shed blood is collected in drains. Tranexamic acid decreases the external blood loss. Some blood loss may be concealed, and the overall effect of tranexamic acid on the haemoglobin (Hb) balance is not known.

METHODS

Patients with osteoarthrosis had unilateral cemented TKA using spinal anaesthesia. In a double-blind fashion, they received either placebo (n=24) or tranexamic acid 10 mg kg(-1) (n=27) i.v. just before tourniquet release and 3 h later. The decrease in circulating Hb on the fifth day after surgery, after correction for Hb transfused, was used to calculate the loss of Hb in grams. This value was then expressed as ml of blood loss.

RESULTS

The groups had similar characteristics. The median volume of drainage fluid after placebo was 845 (interquartile range 523-990) ml and after tranexamic acid was 385 (331-586) ml (P<0.001). Placebo patients received 2 (0-2) units and tranexamic acid patients 0 (0-0) units of packed red cells (P<0.001). The estimated blood loss was 1426 (1135-1977) ml and 1045 (792-1292) ml, respectively (P<0.001). The hidden loss of blood (calculated as loss minus drainage volume) was 618 (330-1347) ml and 524 (330-9620) ml, respectively (P=0.41). Two patients in each group developed deep vein thrombosis.

CONCLUSIONS

Tranexamic acid decreased total blood loss by nearly 30%, drainage volume by approximately 50% and drastically reduced transfusion. However, concealed loss was only marginally influenced by tranexamic acid and was at least as large as the drainage volume.

Timer to shut off portable air samplers

Portable air samplers used at Los Alamos National Laboratory produce noise levels that make it difficult to conduct classes or tours in their vicinity. If air samplers are shut off during a class or tour, it may not be restarted at the end of the class or tour, preventing detection of low level airborne contamination or the measurement of a more significant release during a later operation. To enable clear communication during tours and classes a timer was designed and constructed that allows an air sampler to be shut of for a short, fixed duration and automatically restarted. A schematic and parts list is included.

How reliable are light traps in estimating biting rates of adult Anopheles gambiae s.l. (Diptera: Culicidae) in the presence of treated bed nets?

The sampling efficiency of light trap catches relative to human bait catches in estimating biting rates of the mosquito Anopheles gambiae Giles was investigated in two types of community in southern Sierra Leone: (i) where most of the inhabitants slept under treated bed nets; and (ii) where most of the inhabitants slept without bed nets. The number of female A. gambiae mosquitoes caught in these communities by light trap was strongly correlated (r > or = 0.72) with those from corresponding human biting catches performed either on the same or adjacent nights. It was found that the relative sampling efficiency of light traps varied slightly but significantly with mosquito abundance in villages with treated bed nets, but not in those without them. Nevertheless, the relationship between relative sampling efficiency and mosquito abundance did not differ significantly between the two types of village. Overall, there was insufficient evidence to show that the presence of treated nets altered the relative efficiency of light traps and any bias was only slight, and unlikely to be of any practical importance. Hence, it was concluded that light traps can be used as a surrogate for human bait catches in estimating biting rates of A. gambiae mosquitoes in the two communities.

Early goal-directed therapy in the treatment of severe sepsis and septic shock

BACKGROUND

Goal-directed therapy has been used for severe sepsis and septic shock in the intensive care unit. This approach involves adjustments of cardiac preload, afterload, and contractility to balance oxygen delivery with oxygen demand. The purpose of this study was to evaluate the efficacy of early goal-directed therapy before admission to the intensive care unit.

METHODS

We randomly assigned patients who arrived at an urban emergency department with severe sepsis or septic shock to receive either six hours of early goal-directed therapy or standard therapy (as a control) before admission to the intensive care unit. Clinicians who subsequently assumed the care of the patients were blinded to the treatment assignment. In-hospital mortality (the primary efficacy outcome), end points with respect to resuscitation, and Acute Physiology and Chronic Health Evaluation (APACHE II) scores were obtained serially for 72 hours and compared between the study groups.

RESULTS

Of the 263 enrolled patients, 130 were randomly assigned to early goal-directed therapy and 133 to standard therapy; there were no significant differences between the groups with respect to base-line characteristics. In-hospital mortality was 30.5 percent in the group assigned to early goal-directed therapy, as compared with 46.5 percent in the group assigned to standard therapy (P = 0.009). During the interval from 7 to 72 hours, the patients assigned to early goal-directed therapy had a significantly higher mean (+/-SD) central venous oxygen saturation (70.4+/-10.7 percent vs. 65.3+/-11.4 percent), a lower lactate concentration (3.0+/-4.4 vs. 3.9+/-4.4 mmol per liter), a lower base deficit (2.0+/-6.6 vs. 5.1+/-6.7 mmol per liter), and a higher pH (7.40+/-0.12 vs. 7.36+/-0.12) than the patients assigned to standard therapy (P < or = 0.02 for all comparisons). During the same period, mean APACHE II scores were significantly lower, indicating less severe organ dysfunction, in the patients assigned to early goal-directed therapy than in those assigned to standard therapy (13.0+/-6.3 vs. 15.9+/-6.4, P < 0.001).

CONCLUSIONS

Early goal-directed therapy provides significant benefits with respect to outcome in patients with severe sepsis and septic shock.

Hsp27 protects mitochondria of thermotolerant cells against apoptotic stimuli

Enhanced cell survival and resistance to apoptosis during thermotolerance correlates with an increased expression of heat shock proteins (Hsps). Here we present additional evidence in support of the hypothesis that the induction of Hsp27 and Hsp72 during acquired thermotolerance in Jurkat T-lymphocytes prevents apoptosis. In thermotolerant cells, Hsp27 was shown to associate with the mitochondrial fraction, and inhibition of Hsp27 induction during thermotolerance in cells transfected with hsp27 antisense potentiated mitochondrial cytochrome c release after exposure to various apoptotic stimuli, despite the presence of elevated levels of Hsp72. Caspase activation and apoptosis were inhibited under these conditions. In vitro studies revealed that recombinant Hsp72 more efficiently blocked cytochrome c-mediated caspase activation than did recombinant Hsp27. A model is presented for the inhibition of apoptosis during thermotolerance in which Hsp27 preferentially blocks mitochondrial cytochrome c release, whereas Hsp72 interferes with apoptosomal caspase activation.

Off-pump coronary artery bypass grafting decreases risk-adjusted mortality and morbidity

BACKGROUND

The purpose of this study was to determine whether coronary artery bypass grafting without cardiopulmonary bypass (off-pump CABG) decreases risk-adjusted operative death and major complications after coronary artery bypass grafting in selected patients.

METHODS

Using The Society of Thoracic Surgeons (STS) National Adult Cardiac Surgery Database, procedural outcomes were compared for conventional and off-pump CABG procedures from January 1, 1998, through December 31, 1999. Mortality and major complications were examined, both as unadjusted rates and after adjusting for known base line patient risk factors.

RESULTS

A total of 126 experienced centers performed 118,140 total CABG procedures. The number of off-pump CABG cases was 11,717 cases (9.9% of total cases). The use of an off-pump procedure was associated with a decrease in risk-adjusted operative mortality from 2.9% with conventional CABG to 2.3% in the off-pump group (p < 0.001). The use of an off-pump procedure decreased the risk-adjusted major complication rate from 14.15% with conventional CABG to 10.62% in the off-pump group (p < 0.0001). Patients receiving off-pump procedures were less likely to die (adjusted odds ratio 0.81, 95% CI 0.70 to 0.91) and less likely to have major complications (adjusted odds ratio 0.77, 95% CI 0.72 to 0.82).

CONCLUSIONS

Off-pump CABG is associated with decreased mortality and morbidity after coronary artery bypass grafting. Off-pump CABG may prove superior to conventional CABG in appropriately selected patients.

Outpatient laparoscopic cholecystectomy. A prospective study with 100 consecutive patients

One hundred patients with cholelithiasis were included in a prospective consecutive follow-up study to evaluate laparoscopic cholecystectomy in a day surgical setting. The median operating time was 70 min. In 96% of the patients, it was possible to perform peroperative cholangiography. The median time off work was 7 days and the median time to full recovery was 14 days. Five patients were admitted due to weakness/nausea. Six patients were admitted due to conversion to open surgery or choledocholithiasis. Eighty-nine patients were treated in ambulatory surgery. We conclude that laparoscopic outpatient cholecystectomy can be performed safely with a low unplanned admission rate.