The dexamethasone suppression test in affective illnesses and schizophrenia: Relationship with psychotic symptoms

The authors studied the dexamethasone suppression test (DST) on a series of 112 inpatients including 65 patients with major depressive disorder (21 bipolars: 4 with, 17 without psychotic symptoms; 44 unipolars: 13 with, 31 without psychotic symptoms), 15 patients with depressive disorder, 10 schizoaffective and 22 schizophrenic patients. Using different diagnostic criteria, they confirm the best performances of the DST in depression for the diagnosis of a major depressive disorder, primarily endogenous. They also examined the potential influence of psychotic symptoms, suicidal behavior and family history of affective illness on the DST. The only significant difference found is in the cortisol plasma level at 4 p.m. in bipolar patients with psychotic symptoms. That fact and the high rate of abnormality of the DST in schizoaffective and schizophrenic patients indicate that psychotic symptoms per se may play a role in a dysregulation of the hypothalamo-pituitary adrenal axis.SCOPUS: ar.jinfo:eu-repo/semantics/publishe

Differential computation analysis:hiding your white-box designs is not enough

\u3cp\u3eAlthough all current scientific white-box approaches of standardized cryptographic primitives are broken, there is still a large number of companies which sell “secure” white-box products. In this paper, we present a new approach to assess the security of white-box implementations which requires neither knowledge about the look-up tables used nor any reverse engineering effort. This differential computation analysis (DCA) attack is the software counterpart of the differential power analysis attack as applied by the cryptographic hardware community. We developed plugins to widely available dynamic binary instrumentation frameworks to produce software execution traces which contain information about the memory addresses being accessed. To illustrate its effectiveness, we show how DCA can extract the secret key from numerous publicly (non-commercial) available white-box programs implementing standardized cryptography by analyzing these traces to identify secret-key dependent correlations. This approach allows one to extract the secret key material from white-box implementations significantly faster and without specific knowledge of the white-box design in an automated manner.\u3c/p\u3

Tetany Due to Hypomagnesaemia with Secondary Hypocalcaemia

The case is described of a 5-month-old boy who had convulsions and persistent tetany, associated with hypomagnesaemia and hypocalcaemia. Vitamin D treatment corrected the hypocalcaemia without modifying the clinical status; parenteral magnesium was given, but the child died shortly thereafter. The pathological examination showed calcinosis of the myocardium, kidneys and in one of the cerebral arteries

Differential computation analysis: hiding your white-box designs is not enough

Although all current scientific white-box approaches of standardized cryptographic primitives are broken, there is still a large number of companies which sell “secure” white-box products. In this paper, we present a new approach to assess the security of white-box implementations which requires neither knowledge about the look-up tables used nor any reverse engineering effort. This differential computation analysis (DCA) attack is the software counterpart of the differential power analysis attack as applied by the cryptographic hardware community. We developed plugins to widely available dynamic binary instrumentation frameworks to produce software execution traces which contain information about the memory addresses being accessed. To illustrate its effectiveness, we show how DCA can extract the secret key from numerous publicly (non-commercial) available white-box programs implementing standardized cryptography by analyzing these traces to identify secret-key dependent correlations. This approach allows one to extract the secret key material from white-box implementations significantly faster and without specific knowledge of the white-box design in an automated manner

The dexamethasone suppression test and sleep electroencephalogram in nonbipolar major depressed inpatients: A multivariate analysis

Background: The present study further examined relationships between postdexamethasone cortisol plasma values and sleep electroencephalogram (EEG) parameters. Methods: The dexamethasone suppression test (DST) and polysomnographic recordings were performed in a sample of 300 inpatients with primary major depressive disorder (MDD) (102 men and 198 women, mean age 44 +/- 12 years, range 20-74 years) consecutively admitted to Erasme Hospital (Brussels, Belgium) between 1981 and 1992. Results: The DST was abnormal in 40% of the sample. Postdexamethasone cortisol plasma values at 4:00 PM were significantly influenced by age, but not by gender. They were also significantly and positively correlated with weight loss, total scares on the Hamilton Depression Rating Scale, total scores on the Newcastle Scale, percentage of awakenings during sleep, and percent of stage 1. They were significantly and negatively correlated with percent of stage 2, slow-wave sleep, and REM sleep. Multiple regression analyses were conducted in two successive steps. First among clinical variables, only age and depressive symptom severity remained correlated with postdexamethasone plasma cortisol values. In the second step, with age and severity held constant, postdexamethasone plasma cortisol values were positively associated with amount of wake time and stage 1, and negatively with amount of slow-wave sleep. Conclusions: These findings provide further indirect support for an overarousal state in MDD with sympathoadrenal system hyperactivity and impaired sleep continuity. They also underline the importance of taking into account various clinical confounding factors in the interpretation of both DST and sleep EEG results. (C) 1998 Society of Biological Psychiatry