Effect of age of onset of temporal lobe epilepsy on the severity and the nature of preoperative memory deficits

The nature and severity of pre-operative memory deficits observed in unilateral temporal lobe epilepsy depend upon a number of variables. Among these variables, age of seizure onset seems to be important. The age at which the lesion is sustained could modify the normal functional organization of the brain. Many studies have examined the effect of age of onset on the severity of memory deficits but have seldom focused on the nature of such deficits (verbal/nonverbal) as a function of epileptic focus laterality. This study investigates the effect of age of onset on the nature and severity of memory impairments. Fifty-six epileptics with unilateral temporal lobe epilepsy and 20 normal subjects were administered a neuropsychological evaluation. Four groups of patients were constituted: left or right temporal lobe epilepsy with early (0-5 years) or late (10 years and over) age of seizure onset. The early group showed major verbal and nonverbal memory deficits. The late group presented minor specific deficits: essentially verbal deficits with left temporal lobe seizures and nonverbal deficits with right temporal lobe seizures. These results may be interpreted in the framework of ontogenesis theories of hemispheric specialization.     

Cannabis use correlates with schizotypal personality traits in healthy students

The literature suggests that cannabis use and schizotypal traits both constitute risk factors for the later development of schizophrenia. However, their interrelationships remain to be evaluated. The present study examined the association between cannabis use and schizotypal traits in 232 healthy students who ranged in age from 18 to 25 years. All the students had completed the Schizotypal Personality Questionnaire and four of the Chapman Psychosis Proneness Scales: the Magical Ideation Scale; the Perceptual Aberration Scale; the Revised Physical Anhedonia Scale; and the Revised Social Anhedonia Scale. Subjects were divided into three groups according to cannabis use typology: those who had never used cannabis, those who were past or occasional users, and those who were regular users. Higher scores on the Schizotypal Personality Questionnaire and the Magical Ideation Scale characterized the regular and past or occasional users compared with those who had never used cannabis. The co-occurrence of cannabis use and schizotypal traits appeared to be independent of anxiety and depression dimensions. These data suggest that cannabis use and schizotypal traits have to be jointly considered in further longitudinal studies of schizophrenia risk factors.     

Comparison between macaques' and humans' kinematics of prehension: the role of morphological differences and control mechanisms

Reaching and grasping has been widely studied in both macaques and humans, mainly with the aim of finding similar patterns of behavior in the two species. Little attention has yet been given to how morphological and behavioral differences between the two species might affect the kinematics of the movement. In this study, we present a careful analysis of the similarities and differences between humans' and macaques' prehension movements and discuss these with respect to both the control system and the biomechanics of the arm. Five humans and five macaques performed the same task, namely grasping small feeding objects using a precision grip. Macaques were observed in unconstrained conditions, free to adjust their body posture. The behavioral protocol for macaques revealed a postural preference for sitting and keeping the elbow slightly flexed when applying a precision grip. In agreement with the literature, kinematics revealed general features of movement common to both humans and macaques. However, within a similar timeframe, macaques produced steeper and wider excursion of the elbow and of the wrist, smaller abduction of the shoulder joint and larger displacement of the torso than humans did. The three-joint limb revealed stronger irregularities for the macaques. We hypothesize that the larger kinematic irregularities and the specific elbow--shoulder posture in macaques result in part from an effort of the control system to compensate for different biomechanical constraints, namely for limited shoulder-joint excursion, in order to achieve a similar range of comfort of motion. Finally, we briefly consider the influence of primitive neural circuits responsible for arm motion during locomotion and speculated on their influence on the control of reaching in macaques.     

Contribution of solid-state properties to the aqueous solubility of drugs.

This study investigates the influence of the solid-state properties melting point (T(m)), enthalpy of melting (DeltaH(m)) and entropy of melting (DeltaS(m)) of a drug on its intrinsic solubility (S(0)). For this purpose, 26 chemically and structurally diverse drugs covering the oral drug space were selected and the S(0), T(m), DeltaH(m) and DeltaS(m) were determined experimentally. The influence of T(m), DeltaH(m) and DeltaS(m) on S(0) was studied using regression analysis. The overall improvement of the predictions were 0.3 log units, however, five compounds (astemizole, glyburide, fenbufen, gliclazide and griseofulvin) were improved by more than one log unit. T(m) and DeltaH(m) had a larger effect than DeltaS(m) on the solubility predictions. The well-known general solubility equation (GSE) and the Dannenfelser semi-empirical equation for the calculation of DeltaS(m) were evaluated using our data set. While predictions of drug solubility obtained using the GSE were acceptable, the use of the experimental DeltaS(m) values instead of the constant 56.5 J mol(-1)K(-1) improved the accuracy of the prediction. The Dannenfelser equation underestimated the DeltaS(m) for most compounds with on average 15 J mol(-1)K(-1). Our results show that solid-state properties should be considered for improved performance of future models for prediction of drug solubility. In addition our study provides accurate experimental data on intrinsic solubility for 26 compounds, supplying a useful external data set for validation of drug solubility models.     

Identity development, coping, and adjustment in emerging adults with a chronic illness: the sample case of type 1 diabetes

PURPOSE: The present study focused on identity development in emerging adults (aged 18-30 years) with type 1 diabetes. The three study aims were to examine the following: (1) whether identity development was affected by having diabetes, as compared with development in a nondiabetic sample; (2) how identity development was related to depressive symptoms, coping with diabetes, and diabetes-related problems in the diabetic sample; and (3) whether the pathways from identity development to problems with diabetes and depressive symptoms were mediated through coping strategies in the diabetic sample. METHODS: A total of 194 emerging adults with type 1 diabetes and 344 nondiabetic emerging adults participated. RESULTS: First, using analyses of variance, some mean identity differences between the diabetic and comparison samples were found, with emerging adults with diabetes scoring lower on proactive identity exploration. Using cluster analysis, we found that the same identity types or statuses emerged in both the diabetic and nondiabetic samples. Second, in emerging adults with diabetes, these identity statuses were differentially related to diabetes-related problems, depressive symptoms, and illness coping, with the identity statuses representing a strong sense of identity being accompanied by less diabetes-related problems and depressive symptoms and more adequate coping strategies. Third, using structural equation modeling, the pathways from a strong sense of identity to diabetes-related problems and depressive symptoms were mediated through adaptive and maladaptive coping. CONCLUSIONS: Clinicians should be sensitive to the normative task of identity development in emerging adults with diabetes because identity development can function as a resource in coping with and adjusting to diabetes.     

Enhancement of the bacterial degradation of phenoxyalkanoate herbicides by the use of modified polyurethane foam as a support

The enhancement of the degradative behaviour of Flavobacterium sp. MH concerning the phenoxyalkanoate herbicides 2,4-D, 2,4-DP, 2,4-DB, MCPA, MCPP, and MCPB, respectively, was achieved by the use of an inert polyurethane (PU)-foam. In comparative batch-degradation experiments with and without the addition of the PU-carrier (1.25 % w/v), respectively, the advantages of the PU-supply were demonstrated. When 2,4-D, 2,4-DP, and MCPP, respectively, was used as a growth substrate by strain MH the PU-supply led to a reduced lag-phase. In the case of the stronger toxic phenoxyalkanoates 2,4-DB and MCPB, respectively, the inital substrate concentration (0.1 g/1) was significantly reduced to a minor toxic concentration due to a distinct adsorption to the PU-carrier, thus enabling the biodegradation. Finally, the total initially supplied amount of the phenoxyalkanoates was detoxified as verified by thechloride balance. After several steps of subcultivation, even a five-fold increased MCPB concentration (0.5 g/1) could be detoxified by strain MH in a PU-supplied bubble reactor within several days.     

Formation of PAH-DNA adducts after in vivo and vitro exposure of rats and lung cells to different commercial carbon blacks

OBJECTIVE: The current study was designed to test the possible release and bioavailability of polycyclic aromatic hydrocarbons (PAHs) from a set of commercial carbon blacks (CBs) as well as the ability of these PAHs to form bulky DNA adducts. METHODS: In four commercial CBs (Printex 90, Sterling V, N330, Lampblack 101), leaching of PAH was examined through (1) release of parent PAHs in saline with or without surfactant, and (2) PAH adducts in lung epithelial cells (A549) or in rat lungs after exposure to two CBs (Printex 90, Sterling V) for 13 weeks (50 mg/m(3)). In vitro experiments were done with original and extracted particles, as well as organic extracts of CB in DMSO. As positive controls, B[a]P (0.03 microM) and a mixture of 16 PAHs (0.1 microM) were used. RESULTS: No leaching of PAHs was measured in saline or surfactant-containing saline. In vitro incubations with CB particles (30-300 microg/cm(2)) revealed no adduct spots except for Sterling V. However, the spot was not concentration dependent and remains unidentified. Lung DNA from rats after inhalation of Printex 90 or Sterling V showed no spots related to PAH-DNA adduct formation compared to sham-exposed rats. CONCLUSION: The results suggest that PAHs are very tightly bound to these CBs. Only using organic extracts or particles of low-surface Sterling V, with high PAH content, PAHs may become available to form PAH-DNA adducts. However, the in vitro conditions showing this effect will not be encountered in vivo and renders this mechanism in particle-induced lung cancer at in vivo exposures highly unlikely.     

Acute psychological stress affects glucose concentrations in patients with type 1 diabetes following food intake but not in the fasting state

OBJECTIVE: To compare the effect of acute psychosocial stress on glucose concentrations in the fasting state and following food intake in patients with type 1 diabetes. RESEARCH DESIGN AND METHODS: In study 1, 20 patients were exposed to moderate psychosocial stress by means of the Trier Social Stress Test (TSST) in the fasting state. In study 2, the TSST was applied to 20 additional patients 75 min after intake of a standard meal. Glucose concentrations (by continuous glucose monitoring system), blood pressure, and heart rate were monitored on the control day and on the stress testing day. RESULTS: In both studies, blood pressure increased in response to TSST from 122/77 +/- 14/9 mmHg at baseline to a maximum of 152/93 +/- 21/13 mmHg (P < 0.001), and heart rate increased from 80 +/- 11 to 99 +/- 19 bpm (P < 0.001). In the fasting state (study 1), glucose concentrations remained unchanged during the control day as well as during the stress testing day. In study 2, glucose concentrations were similar on both days before and up to 75 min after the intake of the standard meal. However, a significant delay (of 45 min) in the decrease of glucose concentrations was induced by psychological stress. A two-factor repeated-measures ANOVA revealed a significant difference of glucose concentrations over time (F = 646.65/P < 0.001). CONCLUSIONS: In the postprandial period, acute psychological stress induced a significantly delayed decrease of glucose concentrations, whereas in the fasting state, no effect on poststress glucose concentrations was observed.     

Moderate increase in intraabdominal pressure attenuates gastric mucosal oxygen saturation in patients undergoing laparoscopy

BACKGROUND: Perioperative disturbances of microvascular blood flow and oxygenation in the intestinal tract have been hypothesized to play an important role in development of the multiple organ dysfunction syndrome. Herein, increased intra-abdominal pressure (IAP) has been identified as a key factor in the initiation of the pathophysiologic cascade. The authors hypothesized that increasing the IAP by intraperitoneal insufflation of carbon dioxide attenuates microvascular oxygen saturation in gastric mucosa. They tested this hypothesis in a prospective, observational study in 16 patients scheduled to undergo elective diagnostic laparoscopy. METHODS: The authors continuously assessed microvascular oxygen saturation in gastric mucosa by reflectance spectrophotometry. Simultaneously systemic oxygen saturation, heart rate, arterial blood pressure, and ventilation-derived variables were measured noninvasively. During general anesthesia and controlled mechanical ventilation, baseline values were obtained. Thereafter, the IAP was increased to 8 and 12 mmHg, respectively, followed by a control period after desufflation. RESULTS: The increase in IAP from baseline to 8 mmHg decreased microvascular oxygen saturation in gastric mucosa from 69+/-7% (mean +/- SD) to 63+/-8% at 8 mmHg IAP (P <0.05), with a further significant reduction to 54+/-13% at 12 mmHg IAP (P <0.01). Microvascular oxygen saturation in gastric mucosa recovered rapidly to baseline level (66 +/- 10%) after release of increased IAP. In striking contrast to regional mucosal oxygen saturation, systemic oxygenation did not change with either of the interventions. CONCLUSIONS: The results suggest that increasing intraabdominal pressure to moderate levels, commonly applied to induce a surgical pneumoperitoneum, decreases gastric mucosal oxygen saturation.