Attentional load of the primary task influences the frontal but not the temporal generators of mismatch negativity

According to the model hypothesized by N??t?nen and Michie, the generation of the mismatch negativity (MMN) requires a mismatch detection, taking place in temporal areas, followed by the activation of frontal generators, underlying attention switching toward the deviant stimulus. We aimed at verifying whether the activation of temporal and frontal regions is dependent on the amount of attentional resources allocable toward the deviant stimulus. We recorded event-related potentials (ERPs) in nine healthy subjects while reading and during a demanding visual task (Multiple Features Target Cancellation, MFTC). Raw data were further evaluated by Brain Electrical Source Analysis (BESA). During the Reading condition, distraction toward the unattended auditory stimuli was reflected by the enhancement of the N1 response to frequent stimuli and by the elicitation of a P3a response to deviant ones. The MMN distribution was explained by bilateral temporal dipoles. During the MFTC condition, no P3a was detected, while source analysis showed the activation of a right frontal generator. Temporal dipoles showed no change between the two conditions: we thus conclude that the earlier mismatch detection is independent on the attentional load. By contrast, the activation of a right frontal subcomponent occurred only during the high-load task, independently on any actual attention shift reflected by the P3a component. We thus discuss the hypothesis whether the right frontal MMN generator, rather than subserving a simple attention switching toward the deviant stimulus, plays a role in modulating the auditory change detection system ("contrast enhancement" model).     

Polycystic ovary syndrome and type 2 diabetes mellitus

Polycystic ovary syndrome (PCOS) is a medical condition that has brought multiple specialists together. Gynecologists, endocrinologists, cardiologists, pediatricians, and dermatologists are all concerned with PCOS patients and share research data and design clinical trials to learn more about the syndrome. Insulin resistance is a common feature of PCOS and is more marked in obese women, suggesting that PCOS and obesity have a synergistic effect on the magnitude of the insulin disorder. It leads to increased insulin secretion by beta-cells and compensatory hyperinsulinemia. Hyperinsulinemia associated with insulin resistance has been causally linked to all features of the syndrome, such as hyperandrogenism, reproductive disorders, acne, hirsutism and metabolic disturbances. If beta-cell compensatory response declines, relative or absolute insulin insufficiency develops which may lead to glucose intolerance and type 2 diabetes. Moreover, insulin resistance in PCOS may be considered a risk factor for gestational diabetes (GD).     

Multiple leiomyomas of the vagina in a premenopausal woman

Case report A 32-year-old multiparous woman was seen for a history of dyspareunia and vaginal pain. She presented with two firm masses on the lower-medium left lateral wall of the vagina. Transvaginal ultrasonography showed two spherical smooth-walled masses, respectively of 33 and 35 mm in diameter. A transvaginal approach was used to remove the two tumors en bloc.Conclusion Histologically, the tumors were leiomyomas.     

Prolonged asystolia in a young athlete: a case of sinus arrest during REM sleep

A young asymptomatic male athlete came to our laboratory to be enrolled in a research protocol on physical fatigue. Routine clinical and cardiological evaluations including echocardiogram were in the normal range. Several consecutive cardiopulmonary tests showed a fairly good tolerance to exercise, with no symptoms even when the effort was abruptly arrested. On the other hand, Holter ECG recordings showed long nocturnal sinus pauses. As he was absolutely asymptomatic and free from any structural heart disease, he underwent a follow-up with repeated Holter monitorings for one year. During this period he decided on his own to stop practising sports; in spite of this sharp reduction in his overall physical activity, consecutive Holter monitorings showed that the sinus pauses were progressively increasing in duration (up to 9.2 seconds). With the hypothesis of a malignant vagotonia, he underwent a tilt test; however, we could not elicit any pauses or symptoms. The pauses grew longer over time; a endocavitary electrophysiologic test was performed, which showed no evidence of disease. To rule out the hypothesis of a sleep apnoea syndrome, he also underwent a polysomnography, including EEG, eye movement electromyography, arterial blood oxygen saturation and thoracic impedance: no alterations were detected with the exception of the sinus pauses, which appeared to be strictly linked to REM sleep, as suggested by the concurrent increase in rapid eye movements and desynchronized EEG. We hence made a diagnosis of sinus arrest during REM sleep (SAdRS), a very uncommon disease belonging to the parasomnias. Pauses were then quantified for one month by implanting a ECG loop recorder. As the patient became more and more upset and worried, and the pauses increased to nearly 12 seconds, we decided to implant a pacemaker, which is the only therapeutic option established in the literature for patients with SAdRS.     

Liposome/water lipophilicity: methods, information content, and pharmaceutical applications

This review discusses liposome/water lipophilicity in terms of the structure of liposomes, experimental methods, and information content. In a first part, the structural properties of the hydrophobic core and polar surface of liposomes are examined in the light of potential interactions with solute molecules. Particular emphasis is placed on the physicochemical properties of polar headgroups of lipids in liposomes. A second part is dedicated to three useful methods to study liposome/water partitioning, namely potentiometry, equilibrium dialysis, and (1)H-NMR relaxation rates. In each case, the principle and limitations of the method are discussed. The next part presents the structural information encoded in liposome/water lipophilicity, in other words the solutes' structural and physicochemical properties that determine their behavior and hence their partitioning in such systems. This presentation is based on a comparison between isotropic (i.e., solvent/water) and anisotropic (e.g., liposome/water) systems. An important factor to be considered is whether the anisotropic lipid phase is ionized or not. Three examples taken from the authors' laboratories are discussed to illustrate the factors or combinations thereof that govern liposome/water lipophilicity, namely (a) hydrophobic interactions alone, (b) hydrophobic and polar interactions, and (c) conformational effects plus hydrophobic and ionic interactions. The next part presents two studies taken from the field of QSAR to exemplify the use of liposome/water lipophilicity in structure-disposition and structure-activity relationships. In the conclusion, we summarize the interests and limitations of this technology and point to promising developments.     

The cardiovascular risk factor homocysteine is not elevated in young women with hyperandrogenism or hypoestrogenism

The aim of the present study was to determine whether the plasma concentrations of homocysteine (Hcy) are elevated in women with hypogonadotropic hypogonadism (a condition of chronic hypoestrogenism) and in women with polycystic ovarian syndrome (PCOS, a syndrome characterized by hyperandrogenemia). A cross-sectional study was performed. The plasma concentrations of Hcy were determined in 12 normal-cycling women, in 14 women with hypogonadotropic amenorrhea (HA), and in 20 women with PCOS. The plasma LH, FSH, E(2), testosterone, free testosterone, and androstenedione levels were measured. The blood samples analyzed were taken during the early follicular phase in controls and without regard to the menstrual phase in the patients. Twelve normal-cycling women were compared with 14 women with HA and with 20 women with PCOS. Women with HA or PCOS have plasma concentrations of Hcy similar to those of healthy women with normal menstrual cycles. The results suggest that young women with chronic hypoestrogenism (HA) or hyperandrogenism (PCOS) have plasma concentrations of Hcy similar to those of healthy women with normal menstrual cycles.     

Effects of the selective estrogen receptor modulator, raloxifene, on carotid artery pulsatility index in postmenopausal women

OBJECTIVE: Estrogen replacement therapy after menopause reduces the incidence of arterial disease and cerebrovascular events. The reduced incidence also seems to be due to a positive effect of estrogens on brain blood flow as shown by a decrease in the carotid artery pulsatility index. Raloxifene, a second-generation selective estrogen receptor modulator, has aroused considerable interest because of its tissue-specific agonist-antagonist effect on estrogen receptors. However, there have been no studies on the effect of raloxifene on carotid blood flow after menopause. METHODS: A total of 66 healthy women in postmenopause for more than a year were divided randomly into 2 groups: the first group (n = 33; mean age +/- SD, 53.3 +/- 5.2 years) was treated with raloxifene (one 60-mg capsule per day) for 6 months, and the other group (n = 33; mean age +/- SD, 51.9 +/- 4 years) was untreated. Doppler ultrasonography was used to measure carotid artery pulsatility index (PI) at the beginning of the study and at 2-month intervals. RESULTS: A reduction in carotid artery PI was observed in all patients receiving raloxifene. No significant changes were observed in the control group. The reduction with respect to baseline values was 6.1%(P <.05) after 2 months, 11.2% (P <.05) after 4 months, and 13.2% (P <.05) after 6 months of therapy.The higher the baseline PI, the greater was its reduction after therapy. CONCLUSIONS: After 6 months of therapy, raloxifene induced a reduction in PI similar to that reported after estrogen therapy. The present results further our understanding of the mechanisms by which raloxifene might reduce the incidence of cardiovascular disease in postmenopausal women.     

Neurogenic bladder,neurogenic bowel,and sexual dysfunction in people with spinal cord injury

The purpose of this article is to review the literature related to the effects of spinal cord injuries on genitourinary, gastrointestinal, and sexual function. These important areas of function are profoundly affected by spinal cord injuries, with the effects of injury being dependent on the specific level and degree of neurologic dysfunction. Our ability to manage neurogenic bladder dysfunctions and neurogenic bowel dysfunctions has improved over the past few years; however, in general the techniques used have not significantly changed. In contrast, a significant amount of new information has been made available regarding the effects of specific neurologic injuries on sexual response, particularly female sexual response. Moreover, techniques to remediate erectile dysfunction and infertility in the male have vastly improved the fertility potential of men with spinal cord injuries. Further research is warranted in all of these areas.