Increased salience of gains versus decreased associative learning differentiate bipolar disorder from schizophrenia during incentive decision making.

BACKGROUND: Abnormalities in incentive decision making, typically assessed using the Iowa Gambling Task (IGT), have been reported in both schizophrenia (SZ) and bipolar disorder (BD). We applied the Expectancy-Valence (E-V) model to determine whether motivational, cognitive and response selection component processes of IGT performance are differentially affected in SZ and BD. METHOD: Performance on the IGT was assessed in 280 individuals comprising 70 remitted patients with SZ, 70 remitted patients with BD and 140 age-, sex- and IQ-matched healthy individuals. Based on the E-V model, we extracted three parameters, 'attention to gains or loses', 'expectancy learning' and 'response consistency', that respectively reflect motivational, cognitive and response selection influences on IGT performance. RESULTS: Both patient groups underperformed in the IGT compared to healthy individuals. However, the source of these deficits was diagnosis specific. Associative learning underlying the representation of expectancies was disrupted in SZ whereas BD was associated with increased incentive salience of gains. These findings were not attributable to non-specific effects of sex, IQ, psychopathology or medication. CONCLUSIONS: Our results point to dissociable processes underlying abnormal incentive decision making in BD and SZ that could potentially be mapped to different neural circuits.

Linguistic production and syntactic comprehension in schizophrenia and bipolar disorder.

OBJECTIVE: To explore linguistic abilities in schizophrenia and bipolar disorder. Specifically, the aims of this study were to: i) investigate microlinguistic (lexicon, morphology, syntax) and macrolinguistic (discourse coherence, pragmatics) dimensions of speech production and ii) evaluate syntactic comprehension skills in both schizophrenia and bipolar disorder. METHOD: Linguistic performance of 30 Italian-speaking patients with schizophrenia, 30 participants with bipolar disorder and 30 healthy controls comparable for age and educational level has been assessed using a story-telling task and a computer-based test of syntactic comprehension. RESULTS: In narrative production, compared with healthy participants, those with schizophrenia had slight problems in speech rate and deficits at both local and global discourse coherence, whereas patients with bipolar disorder showed reduced mean length of utterance. As regards syntactic comprehension, both groups of patients collected more grammatical errors than controls, but they differed with regard to the number and kind of grammatical construction they missed. CONCLUSION: Linguistic deficits have been detected in both groups of patients, being, however, more severe and generalized in schizophrenia than in bipolar disorder. Such results help us in improving our understanding of the potential psychopathological overlapping between these disorders.

Effects of fasting and hypoxic preconditioning on the hypoxic-reoxygenated ventricular strips of the rat heart.

The investigation aimed to assess the effects of hypoxic preconditioning in right ventricle strips of fed and 24-h fasted rats, which display a fast fatty acid catabolism, and to ascertain whether these effects are associated with changes in the tissue levels of long-chain acylCoA and acyl carnitine and glycolytic activity. Strips were mounted isometrically in Krebs-bicarbonate solution with 10 mM dextrose and paced at 1 Hz. Strips were exposed to 30 min hypoxia and 60 min reoxygenation with or without a previous preconditioning cycle of 5 min hypoxia followed by a 10 min reoxygenation. During hypoxia the fasted rat strips underwent a greater contracture with respect to the fed group. Preconditioning reduced the contracture strength and accelerated the post-hypoxic recovery only in the fasted rat strips. Hypoxia evoked an increase in the acylCoA and acyl carnitine tissue-contents of the strips which reached higher levels in the fasted than in the fed rat groups. Preconditioning had no effects on the content of these metabolites. During hypoxia lactate output was lower in the fasted than in the fed rat strips and preconditioning abolished this decrease. These data suggest that the protective effects of hypoxic preconditioning occur in the heart tissue predisposed to the oxidation of fatty acid and can not be ascribed to changes in the accumulation of acylCoA and acyl carnitine but could be due, at least in part, to an activation of glycolysis.

Influence of fasting on the effects of ischemic preconditioning in the ischemic-reperfused rat heart.

The effects of fasting and ischemic preconditioning (IP) on heart function of Langendorff-perfused rat hearts exposed to 25 min global ischemia plus 30 min reperfusion (RP), were correlated with lactate release and tissue-levels of long-chain acyl carnitine (LCCa) and CoA (LCCoA). IP was achieved by a 3 min ischemia plus a 5 min reperfusion cycle. Creatine kinase leakage was measured to assess the extent of cardiac injury. Fasting reduced the ischemic-induced contracture, improved RP recovery of mechanical function, reduced lactate release and increased the end-ischemia LCCoA and LCCa levels. Both in the fed and the fasted rat hearts IP delayed the pacemaker depression, reduced the amplitude of ischemic contracture and improved the RP recovery of contraction. However, IP reduced creatine kinase and lactate release only in the fed rat hearts. IP had no effects on tissue LCCa and LCCoA in both groups. These data suggest that: 1) beneficial effects of fasting may be ascribed, at least in part, to a reduced lactate production which may attenuate ischemic myocyte acidification and to the accumulation of fatty acyl esters which would favour citric acid cycle replenishment during RP. 2) beneficial effects of IP could be in part explained by the reduction of lactate production in the fed group although data obtained with the fasted rat heart indicate that another mechanisms must also be involved in the effects of IP. 3) accumulation of LCCoA and LCCa is not involved in the noxious effects of ischemia as well as in the protection effected by IP.

Effects of hypoxic preconditioning on the hypoxic-reoxygenated atria from fed and fasted rats.

Hypoxic preconditioning (PC) was studied using rat atria set up isometrically in 10 mM dextrose medium and paced at 1 Hz, applying three different protocols wherein fed and 24-h fasted rats were used in protocols 1 and 2 and only the fed in protocol 3. In protocol 1, PC was achieved applying a 5 min hypoxia followed by 10 min of reoxygenation before the onset of a 60 min hypoxia and 60 min reoxygenation. In protocol 2 the 5 min and a posterior 45 min hypoxia were applied in the absence of dextrose whereas in the 10 min and 60 min reoxygenation periods dextrose was present. In protocol 3, two cycles of 5 min dextrose-free hypoxic periods were applied before the sustained hypoxia (dextrose-free) and reoxygenation periods (10 min and final 45 min, both in the presence of dextrose). In the control groups of all protocols, the equilibration periods were prolonged to compensate the duration of PC. In the control groups of protocols 1 and 2, the sustained hypoxia evoked greater disturbances of contractility and a smaller post-hypoxic recovery in the fasted than in the fed rat atria. In protocol 1, PC markedly reduced the rise in resting tension and improved the post-hypoxic recovery in the fasted rat atria whereas in the fed rat atria protective effects were small and brief. In protocol 2, PC evoked a small reduction of contracture only in the atria from fasted rats and in protocol 3, PC exacerbated the hypoxic disturbances. These data suggest that PC effects depend both on the severity of the PC stress and the sustained hypoxia; and that PC does not require coronary flow.

Reliability of applanation tonometry readings obtained with a disposable latex cap.

BACKGROUND: To verify the accuracy of applanation tonometry through disposable latex caps used to prevent transmission of infectious diseases. METHODS: Tonometry was performed in 80 patients. Each patient underwent two intraocular pressure (IOP) measurements with and without the latex. In group A patients tonometry was performed first without the cap; in group B tonometry was performed first with the cap. Each group was also divided into patients with IOP, >/=20 mm Hg (A1; B1) and patients with IOP <20 mm Hg (A2; B2). RESULTS: The mean difference of tonometry readings was equal to -0.36 +/- 1. 62 mm Hg in group A, -0.03 +/- 1.77 mm Hg in group A1, -0.61 +/- 1. 45 mm Hg in group A2, 0.23 +/- 1.44 in group B, 0.64 +/- 1.41 mm Hg in group B1, 0.05 +/- 1.42 in group B2. A statistically significant correlation was found in group A, in group A2, B, B1 and B2; a less significant correlation was found in group A1. CONCLUSIONS: The use of the latex caps does not alter the reliability of tonometry readings as long as the cap is applied tightly. Measurement variation in our study is comparable to published data on applanation tonometry.

Effects of pentanoate, 4-pentenoate, 3-hydroxybutyrate and insulin on the tissue-levels of long-chain acyl CoA and acylcarnitine in the oxygenated and hypoxic rat atria.

Under hypoxic conditions the atrial contents of long-chain acyl CoA (LCCoA) and long-chain acylcarnitine display a close correlation with the noxious effects of fasting on the atrial functions as well as with the amelioration effected by inhibitors of carnitine palmitoyltransferase I. These findings suggested that fatty acid oxidation was detrimental for the hypoxic atria. However, since changes of the LCCoA and LCCa levels which may occur together with the hypoxic disturbances attained under some other metabolic interventions had not been assessed yet, present investigation aimed to provide information about this issue. At the end of the prehypoxic equilibration period, all the treatments tested evoked a fall of the free-CoA levels whereas free-carnitine, LCCoA and LCCa remained unchanged. In the hypoxic atria, 4-pentenoate, an inhibitor of fatty acid beta-oxidation that also can be oxidized, did not change LCCoA and LCCa levels whereas the readily oxidizable pentanoate evoked a drop of LCCoA. These effects may be due to the trapping of CoA as the short-chain acyl esters of both substances. Since 4-pentenoate and pentanoate were noxious on the hypoxic atria even though they did not increase LCCoA and LCCa contents, it may be inferred that short-chain acyl esters might be deleterious during oxygen shortage. The exposure to 3-hydroxybutyrate, an oxidizable substrate whose availability increases during fasting, did not alter the LCCoA and LCCa contents, agreeing with the weak detrimental effects that it exerts on the hypoxic atria. On the other hand, insulin elicited a rise in the LCCoA and a fall in the LCCa contents. Inasmuch insulin had been shown to improve the performance of the hypoxic atria, these findings suggest that LCCoA might not be involved in the noxious effects of fatty acid oxidation whereas LCCa would be the major toxic catabolite.

Post-operative analgesia with tramadol: a controlled study compared with an analgesic combination.

The analgesic action of tramadol in the post-operative period was compared with that of an analgesic combination (Nisidin) in a sample of 60 patients (31 male, 29 female) aged between 20 and 70 years undergoing surgical operations on the abdomen involving opening of the peritoneum. The study was carried out according to a controlled and randomized experimental design. Tramadol in 100 mg/2 ml vials and Nisidin in 2 ml vials were administered parenterally at a dosage of three vials a day during the first three days of the post-operative period. The analgesic action of tramadol was shown to be more effective than that of Nisidin both after the first dose and during the three days of observation (p < 0.01). Local and general safety were good in both groups, and respiratory and heart rates did not undergo clinically significant modifications. In conclusion, tramadol proves to be particularly indicated in the treatment of post-operative pain, given that it has analgesic action combined with good local and general safety.

[The skull in renal osteodystrophy]. / Il cranio nell'osteodistrofia renale.

Skull X-rays of 60 patients with chronic renal failure were examined. Alterations included diminished or increased bone density, radiolucent areas, pepper pot skull and the disappearance of vascular grooves and sutures. It is suggested that the radiological aspect of the skull is of very little diagnostic use in the assessment of uremic osteopathy since specific alterations are rare and tardive and show no correlation with clinical and laboratory findings. Skull X-rays can be useful in assessing the effects of treatment (vitamin D derivatives, parathyroidectomy) and for the identification of focal lesions (brown tumors).