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Vickrey auctions (VA) and Becker-DeGroot-Marschak auctions (BDM) are strategically equivalent demand-revealing mechanisms, differentiated only by a human opponent in the VA, and a random-number-generator opponent in the BDM. Game parameters are such that players are incentivized to reveal their private subjective values (SV) and behavior should be identical in both tasks. However, this has been repeatedly shown not to be the case. In this study, the neural correlates of outcome feedback processing during VA and BDM were directly compared using electroencephalography. Twenty-eight healthy participants bid for household products which were then divided into high- and low-SV categories. The VA included a human opponent deception to induce a social environment, while in reality a random-number-generator was used in both tasks. A P3 component peaking at 336 ms over midline parietal sites showed more positive amplitudes for high bid values, and for win outcomes in the VA but not the BDM. Both auctions also elicited a Reward Positivity potential, maximal at 275 ms along the central midline electrodes, that was not modulated by auction task or SV. Further, an exploratory N170 potential in the right occipitotemporal electrodes and a vertex positive potential component were stronger in the VA relative to the BDM. Results point to an enhanced cortical response to bid outcomes during VA task in a potential component associated with emotional control, and to the occurrence of face-sensitive potentials in VA but not in BDM auction. These findings suggest modulation of bid outcome processing by the social-competitive aspect of auction tasks. Directly comparing two prominent auction paradigms affords the opportunity to isolate the impact of social environment on competitive, risky decision-making. Findings suggest that feedback processing as early as 176 ms is facilitated by the presence of a human competitor, and later processing is modulated by social context and subjective value.

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Two cases of intestinal perforation associated with inguinal hernia or incisional hernia are presented along with a review of the literature. The great majority are men over the age of 45 with a reducible and usually right-sided inguinal hernia. When a loop of bowel lies opposite a point of weakness in the abdominal wall, such as a hernial orifice, and intraabdominal pressure suddenly rises, the resulting intraluminal pressure ruptures the bowel where it is unsupported. Perforation results in diffuse peritonitis in a few hours. The treatment consists in laparotomy, simple closure of the perforation and drainage of the abdomen. Repair of the hernia is recommended 2 months after healing of the peritonitis. If the complication is early detected and treated the outcome is good.

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Snowboarding has become increasingly popular in recent years. A prospective multicenter study was therefore performed during the winter 1992/93. 345 injuries were analysed and compared with 305 healthy snowboarders on the slopes. Preliminary results show predominantly injuries of the upper extremity comparative to those suffered from alpine skiing. Protection of the hand and wrist is recommended as well as an instruction for a special technique for falling as measurements for accident prevention.

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In 1983, a chromosome analysis was carried out in a newborn preterm infant with minor anomalies (preauricular skin tag, maldescensus testis). All analysed metaphases showed a small extra chromosome, which was symmetric, dicentric and bi-satellited. In spite of in depth analysis, its origin remained obscure. Recent re-evaluation using fluorescence in situ hybridization (FISH) led to the diagnosis of a dicentric chromosome 22. The FISH technique is an important new tool in chromosome diagnostics. The phenotype of this infant only vaguely resembles the cat eye syndrome. The syndrome should be diagnosed clinically and not only based on the results of chromosome analysis.

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The effects of adenosine, the Ri site adenosine receptor agonist (-)-N6-phenylisopropyladenosine (PIA), the Ra site agonist 5'-N-ethylcarboxamideadenosine (NECA) and the P site agonist 2',5'-dideoxyadenosine (DIDA) on force of contraction, cyclic AMP (cAMP) and cyclic GMP (cGMP) content and on transmembrane action potential were studied in isolated electrically driven left auricles and papillary muscles from guinea pigs. Furthermore, the effects on adenylate cyclase activity in a particulate membrane preparation were investigated. In the auricles, adenosine, PIA and NECA had negative inotropic effects which were accompanied by a shortening of the action potential. Theophylline antagonized these effects which are likely mediated by R site adenosine receptors. DIDA was ineffective. Except for a small positive inotropic effect of adenosine the analogs were ineffective in the papillary muscles. None of the mechanical effects was accompanied by a change in cAMP and cGMP content in the intact preparations. In the broken cell preparation PIA and NECA had no effect on adenylate cyclase activity. Adenosine and DIDA inhibited the enzyme. The latter effects can be classified as P site-mediated effects. In conclusion, distinct mechanical, i.e., negative inotropic effects of adenosine and its analogs in the heart are observed in auricular preparations only. These effects are unlikely to be related to the cAMP and/or cGMP system. Instead, they are probably due to a direct shortening of the action potential which, in turn, is conceivably due to an increase in K+ outward current and a secondary decrease in Ca++ inward current. This effect is apparently mediated by cardiac R site adenosine receptors which are not detectably coupled to adenylate cyclase.

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Short term alterations of plasma corticotrophin immunoreactivity (ACTH) and cortisol were studied in healthy men under basal conditions and during intravenous administration of metyrapone. In the intravenous experiment, a low dose (1 g/5 h) and a high dose (4 g/5 h) of metyrapone ditartrate were infused. In the early phase of the metyrapone experiments, plasma ACTH fell from 9.46 +/- 0.95 (SE) pmol/l at 08.00 h to 7.7 +/- 1.1 pmol/l at 09.00 h (P greater than 0.05) in the low-dose experiment, and from 7.0 +/- 1.6 pmol/l to 4.6 +/- 0.9 pmol/l (P less than 0.05) in the high-dose experiment. A significant delayed increase of plasma ACTH secondary to the hypocortisolaemic stimulus was apparent in the high-dose experiment, in which plasma cortisol was maximally suppressed to 14 +/- 3 nmol/l at 13.00 h. No significant increase was observed in the low-dose experiment, the maximal suppression of plasma cortisol being 46 +/- 9 nmol/l at 14.00 h. The present data suggest dual effects of metyrapone on plasma ACTH: 1) a suppressive effect, the mechanism of which is not yet understood, and 2) the known increasing effect of 'feed-back' stimulation, which seems to be very sensitive to alterations of plasma cortisol only at cortisol levels lower than about 50 nmol/l. The suppressive effect of metyrapone may account for the frequently described inadequate response of plasma ACTH to metyrapone-induced hypocortisolaemia. Particularly, the diagnostic validity of the very short versions of the metyrapone test would seem to be seriously questioned.

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Monitoring of serum glucose levels in 60 asymptomatic overweight (4.000-4.499 g) and giant (greater than 4.500 g) newborns of non-diabetic mothers during the first 72 hours of life did not reveal pathological values. The mean result of giant infants was lower than that of the group less than 4.500 g. In mothers of overweight infants diabetes mellitus should always be kept in mind. However, the diagnosis may be difficult particularly in its latent form due to metabolic alterations caused by pregnancy. For this reason it is necessary to monitor blood glucose levels for hypoglycemia in these newborns just as in infants of mothers having a manifest diabetes mellitus.

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The diurnal variations of the plasma concentrations of eleven steroid hormones and of corticotropin (ACTH) were studied in ten young healthy males. The plasma steroids progesterone, pregnenolone, deoxycorticosterone, 17-OH-progesterone, 17-OH-pregnenolone, deoxycortisol, 18-OH-deoxycorticosterone, corticosterone, aldosterone, cortisol and 18-OH-corticosterone, as well as plasma ACTH, were measured at 30-min intervals in the morning and in the evening and at 2-h intervals during the rest of the day. Steroids were extracted from 1 ml plasma, fractionated by high-pressure liquid chromatography (HPLC) and finally quantified by radioimmunoassay (RIA). Plasma concentrations of ACTH were radioimmunoassayed after extraction from 2 ml plasma. More or less pronounced circadian and episodic variations were apparent for plasma levels of all steroids studied, as well as of ACTH. According to related profiles of diurnal variations of plasma concentrations, three different categories of steroids were tentatively crystallized. Category 1 includes 17-OH-pregnenolone, deoxycortisol, corticosterone, 18-OH-deoxycorticosterone, deoxycorticosterone, cortisol and 18-OH-corticosterone, exhibiting a rhythm partly synchronous with that of the pituitary secretory activity of ACTH. Category 2, including progesterone, pregnenolone and 17-OH-progesterone, exhibited a time course of plasma concentrations assuming a regulation predominantly dictated by the testicular secretory activity. Lastly, aldosterone exerted a variation of plasma concentrations which was obviously regulated by the renin-angiotensin system under the present conditions.

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Using reversed-phase "high-performance" liquid chromatography and hydrophilic ion-pairing reagents, we studied the chromatographic profiles of corticotropin immunoreactivities in human plasma, cerebrospinal fluid, and urine. The chromatographic system we applied provides excellent separation of peptide molecules, with reproducibility (CV) of retention times better than 0.5%, and makes feasible the subsequent immunological quantitation of eluted fractions. Profiles of corticotropin immunoreactivities exhibited several chemically different compounds in each of the three body fluids studied. A considerable portion of these immunoreactive compounds is more hydrophilic and probably of lower molecular mass than the human corticotropin 1-39 molecule itself. These hydrophilic molecules are more predominant in urine and plasma than in cerebrospinal fluid.

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A convenient solid phase method for extracting and fractionating steroid hormones from serum or urine is presented. The influence of the solvent used for extraction, of the body fluid to be extracted, and of the degree of sample dilution on the efficiency of extraction was studied for progesterone and cortisol. The potency of fractionation was demonstrated by the separation of the steroid pairs, deoxycortisol--cortisol and oestradiol--oestriol, from a urine sample. Influence of ionic strength, pH and temperature on the reproducibility was assessed for deoxycortisol in undiluted urine. With respect to practicability and efficiency, this method has proved to be considerably superior to conventional liquid-liquid techniques.

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A radioimmunological method for the sensitive estimation of plasma corticotropin immunoreactivity (ACTH) using commercially available reagents is presented. The method involves silica extraction of corticotropin from plasma, desorption with acid protein solution, neutralization and subsequent radiomimmunoassay (RIA). [125I]corticotropin is added as internal standard to the plasma sample. The amounts of corticotropin extractable with silica differed considerably between the plasma samples of individual subjects. There were marked differences in the affinity of five different corticotropin standards to the antiserum used. The detection limit of the method was found to be 1.47 pmol/l. Blanks arising in water and in charcoal stripped serum were lower than the detection limit. Precision and accuracy were within the range commonly achieved for RIA-methods. Morning levels of normal subjects ranged from 6.5-10.9-18.5 pmol/l. Hydrocortisone infusion suppressed plasma corticotropin from 12.6 +/- 6.4 (S.D.) to 4.4 +/- 3.1 (S.D.) pmol/l. Infusion of metyrapone increased corticotropin levels from 7.3 +/- 4.2 (S.D.) to 15.3 +/- 6.0 (S.D.) pmol/l.

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An assay for the specific measurement of urinary free cortisol excretion is described. The method involves a simple solid-phase extraction, automatic high pressure liquid chromatography (HPLC) and radioimmunological quantification. The concurrent study on antigenically interfering compounds in the organic extract of urine revealed that non-specific immunoreactivities with a chromatographic behaviour very similar to cortisol are present in urine, which are not attributable to the steroids commonly studied for cross-reactivity. Non-chromatographed values are about twice as high as those chromatographed by HPLC. Correlation between them was significant (r = 0.98). Precision and accuracy of the present method are within the range commonly achieved by radioimmunoassay methods. The normal range of urinary free cortisol excretion was found to be 28--117 nmol/24 h (n = 128). The present method, suitable for routine purposes, provides a basis for external quality control of urinary cortisol estimations, which is inadequate with the non-specific methods usually applied.

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In a retrospective study of 150 twins born between 1970-1977, birth weight, length, and head circumference was plotted against gestational age. In comparison to singletons, all 3 parameters were low normal. While length and head circumference values follow the growth pattern of singletons, prenatal birth weight shows a progressive decline toward maturity. The intrauterine growth pattern of twins resembles that of intrauterine growth retardation of singletons.

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