Secretion of vascular endothelial growth factor/vascular permeability factor from human luteinized granulosa cells is human chorionic gonadotrophin dependent

Vascularization is a prominent event during corpus luteum formation, providing low density lipoproteins for steroid biosynthesis and enabling transport of secreted steroids. The process of vascularization is controlled by specific regulators. Vascular endothelial growth factor (VEGF), otherwise named vascular permeability factor (VPF), induces endothelial cell proliferation as well as angiogenesis in vivo and increases capillary permeability. Here we report the expression of VEGF/VPF mRNA by cultured human luteinized granulosa cells (GC) for at least 10 days. Without HCG VEGF/VPF expression declined after day 4 and by day 10 was reduced to approximately 30% of the value at day 4. However, after culture in the presence of 1 U/ml human chorionic gonadotrophin (HCG), expression of VEGF/VPF mRNA by GC was four times greater than control experiments by day 10, and increased 100% from day 4 to day 10. Simultaneously, HCG supplementation increased VEGF/VPF secretion by GC. Medium VEGF/VPF on day 3 was 13 pM without and 11 pM with HCG. Medium VEGF/VPF on day 10 was 6 pM without HCG and 29 pM with HCG. These results suggest that vascularization of the corpus luteum is induced by HCG-mediated effects of VEGF/VPF.      

A basis for electronic cognitive simulation: the heuristic patient

Although medical trainees are expected to become expert quickly and safely, limited electronic methods are available to rehearse medical cognition for common outpatient and non-emergent inpatient problems. We conducted a series of formal observational sessions designed to determine what interaction requirements are desirable for student rehearsal of medical management by using an electronic patient. The studies utilized both manual and electronic methods for a student to evaluate and manage patients with medical and surgical problems. We observed the following major requirements for an effective simulation experience: the user must have a trial-and-error experience with the patient; the user must have unconstrained access to query and treat the patient; anatomic and physiologic values in the patient must change appropriately in response to user actions; and the user must be able to control certain time-related aspects of the simulation. When these requirements are implemented within a simulation, user-directed management of an electronic patient, by itself, becomes a strong aid to learning by trial- and-error techniques. We conclude that the heuristic patient is a practical and useful concept. Once fully developed, it would allow rehearsal of patient care decision making, intrinsically demonstrating trainee knowledge deficits, and resulting in self-directed learning.     

Streufunktionen polymolekularer substanzen bei der inelastischen lichtstreuung

The behaviour of polydisperse substances in inelastic light scattering is examined theoretically. Normalized relations for the spectrum and the corresponding autocorrelation function as observed by a photomultiplier are given. The relations contain sums of products of the scattering functions with Lorentz functions or exponential functions which represent z-averages. Examples for polymers with Schulz distributions of the molecular weight are calculated and the influence of the relaxation time is determined. For the inverse problem, namely to find the molecular weight distribution from scattering experiments, different analytical and numerical solutions are given. The influence of experimental errors on the molecular weight and the width of the distribution is discussed.     

White matter microstructural abnormalities in the frontal lobe of adults with antisocial personality disorder

Antisocial personality disorder (ASPD) and psychopathy involve significant interpersonal and behavioural impairments. However, little is known about their underlying neurobiology and in particular, abnormalities in white matter (WM) microstructure. A preliminary diffusion tensor magnetic resonance imaging (DT-MRI) study of adult psychopaths employing tractography revealed abnormalities in the right uncinate fasciculus (UF) (Craig et al., 2009), indicating fronto-limbic disconnectivity. However, it is not clear whether WM abnormalities are restricted to this tract or are or more widespread, including other tracts which are involved in connectivity with the frontal lobe.We performed whole brain voxel-based analyses on WM fractional anisotropy (FA) and mean diffusivity (MD) maps acquired with DT-MRI to compare 15 adults with ASPD and healthy age, handedness and IQ-matched controls. Also, within ASPD subjects we related differences in FA and MD to measures of psychopathy.Significant WM FA reduction and MD increases were found respectively in ASPD subjects relative to controls. FA was bilaterally reduced in the genu of corpus callosum while in the right frontal lobe FA reduction was found in the UF, inferior fronto-occipital fasciculus (IFOF), anterior corona radiata and anterior limb and genu of the internal capsule. These differences negatively correlated with measures of psychopathy. Also in the right frontal lobe, increased MD was found in the IFOF and UF, and the corpus callosum and anterior corona radiata. There was a significant positive correlation between MD and psychopathy scores.ConclusionsThe present study confirms a previous report of reduced FA in the UF. Additionally, we report for the first time, FA deficits in tracts involved in interhemispheric as well as frontal lobe connectivity in conjunction with MD increases in the frontal lobe. Hence, we provide evidence of significant WM microstructural abnormalities in frontal brain regions in ASPD and psychopathy.     

The relationship of movement time to hand-foot laterality patterns

Asymmetries in movement times of the hands in 60 healthy participants with different patterns of hand-foot dominance were investigated. Handedness and footedness were assessed by means of questionnaires and verified by simple motor tasks. Psychomotor performance was evaluated by the use of selected tests from the computerised Vienna Test System (VST, Vienna, Austria). Movement time (MT) was assessed separately for dominant and non-dominant hands in a unimanual simple reaction task. Participants performed significantly better with their preferred hand, and differences in performance between right- and left-handers were not significant, neither was there a main effect of foot dominance on MT of the hands. However there was a significant effect of laterality pattern in hand-foot combination on hands MT: participants with cross-lateral dominance patterns of hands and feet performed significantly better than those with congruent hand-foot dominance. No significant interaction with sex was found. These results provide evidence for a lack of independence of hand and foot dominance in motor performance, suggesting the functional significance of limb laterality pattern in the motor control system. The results support the hypothesis that the quality of human hand movements may be influenced not only by central information processing (hemispheric specialisation) but also by other structures and processes of motor control, such as central pattern generators (CPGs) and biomechanical factors.