Recognition memory of newly learned faces

We used event-related fMRI to study recognition memory of newly learned faces. Caucasian subjects memorized unfamiliar, neutral and happy South Korean faces and 4 days later performed a memory retrieval task in the MR scanner. We predicted that previously seen faces would be recognized faster and more accurately and would elicit stronger neural activation than novel faces. Consistent with our hypothesis, novel faces were recognized more slowly and less accurately than previously seen faces. We found activation in a distributed cortical network that included face-responsive regions in the visual cortex, parietal and prefrontal regions, and the hippocampus. Within all regions, correctly recognized, previously seen faces evoked stronger activation than novel faces. Additionally, in parietal and prefrontal cortices, stronger activation was observed during correct than incorrect trials. Finally, in the hippocampus, false alarms to happy faces elicited stronger responses than false alarms to neutral faces. Our findings suggest that face recognition memory is mediated by stimulus-specific representations stored in extrastriate regions; parietal and prefrontal regions where old and new items are classified; and the hippocampus where veridical memory traces are recovered.     

Recognition memory is modulated by visual similarity

We used event-related fMRI to test whether recognition memory depends on visual similarity between familiar prototypes and novel exemplars. Subjects memorized portraits, landscapes, and abstract compositions by six painters with a unique style, and later performed a memory recognition task. The prototypes were presented with new exemplars that were either visually similar or dissimilar. Behaviorally, novel, dissimilar items were detected faster and more accurately. We found activation in a distributed cortical network that included face- and object-selective regions in the visual cortex, where familiar prototypes evoked stronger responses than new exemplars; attention-related regions in parietal cortex, where responses elicited by new exemplars were reduced with decreased similarity to the prototypes; and the hippocampus and memory-related regions in parietal and prefrontal cortices, where stronger responses were evoked by the dissimilar exemplars. Our findings suggest that recognition memory is mediated by classification of novel exemplars as a match or a mismatch, based on their visual similarity to familiar prototypes.     

Caramiphen and scopolamine prevent soman-induced brain damage and cognitive dysfunction

Exposure to soman, a toxic organophosphate nerve agent, causes severe adverse effects and long term changes in the peripheral and central nervous systems. The goal of this study was to evaluate the ability of prophylactic treatments to block the deleterious effects associated with soman poisoning. scopolamine, a classical anticholinergic agent, or caramiphen, an anticonvulsant anticholinergic drug with anti-glutamatergic properties, in conjunction with pyridostigmine, a reversible cholinesterase inhibitor, were administered prior to sbman (1 LD50). Both caramiphen and scopolamine dramatically attenuated the process of cell death as assessed by the binding of [3H]RoS-4864 to peripheral benzodiazepine receptors (omega3 sites) on microglia and astrocytes. In addition, caramiphen but not scopolamine, blocked the soman-evoked down-regulation of [3H]AMPA binding to forebrain membrane preparations. Moreover, cognitive tests utilizing the Morris water maze, examining learning and memory processes as well as reversal learning, demonstrated that caramiphen abolished the effects of soman intoxication on learning as early as the first trial day, while scopolamine exerted its effect commencing at the second day of training. Whereas the former drug completely prevented memory deficits, the latter exhibited partial protection. Both agents equally blocked the impairment of reversal learning. In addition, there is a significant correlation between behavioral parameters and [3H]RoS-4864 binding to forebrain membrane preparations of rats, which participated in these tests (r(21) = 0.66, P < 0.001; r(21) = 0.66, P < 0.001, -0.62, P < 0.002). These results demonstrate the beneficial use of drugs exhibiting both anti-cholinergic and anti-glutamatergic properties for the protection against changes in cognitive parameters caused by nerve agent poisoning. Moreover, agents such as caramiphen may eliminate the need for multiple drug therapy in organophosphate intoxications.     

Elevated levels of CRP in ovarian hyperstimulation syndrome: an unrecognised potential hazard?

OBJECTIVE: Elevated levels of C-reactive protein (CRP) were found recently to be a crucial marker for cardiovascular disease. This protein might have a role in endothelial cell activation, vascular damage and a thrombotic tendency. We sought to determine whether concentrations of CRP are altered in women with controlled ovarian hyperstimulation (COH) or hyperstimulation syndrome (OHSS). DESIGN: A prospective cohort study. SETTING: The gynecology department and IVF unit of the Lis maternity hospital. POPULATION: Twenty women with OHSS, 20 women undergoing COH and 20 women who participated as controls were included in the study. METHODS: Venous blood was withdrawn for analysis of high sensitive C-reactive protein (hs-CRP) using the Boering BN-II nephelometer. MAIN OUTCOME MEASURES: hs-CRP levels were determined. RESULTS: There was a significant (P < 0.05) difference in the hs-CRP concentrations in women with OHSS compared with women with COH and controls. The respective values for hs-CRP were 19.0 [4.0], 7.0 [1.7] and 4.6 [1.1] mg/L. CONCLUSIONS: Women with OHSS have elevated concentrations of hs-CRP. This finding, previously believed to merely represent an acute phase response, may actually represent a yet unrecognised pathophysiological factor of this syndrome and pave the way for new investigational directions of this potentially hazardous condition.     

Decreased expression of tissue inhibitor of matrix metalloproteinases in follicular fluid from women with polycystic ovaries compared with normally ovulating patients undergoing in vitro fertilization

OBJECTIVE: To compare activity of matrix metalloproteinases (MMP) and expression of their tissue-specific inhibitor (TIMP) in the follicular fluid of normally ovulating women and women with the polycystic ovary syndrome (PCOS). DESIGN: Prospective study. SETTING: IVF unit and endocrine research unit. PATIENT(S): Fourteen patients undergoing IVF treatment (seven with normal ovulation and seven with PCOS). MAIN OUTCOME MEASURE(S): Activity of MMP-2 and MMP-9 and expression of MMP-1, TIMP-1, and TIMP-2 was measured in follicular fluid of the leading follicles by using gel zymography and immunoblot analysis. RESULT(S): The activity of MMP-2 and MMP-9 and expression of MMP-1 was similar in follicular fluid of normally ovulating patients and patients with PCOS. Significantly lower expression of TIMP-1 was found in follicular fluid of patients with PCOS women compared with normally ovulating patients. CONCLUSION(S): Because MMPs and TIMPs play a role in the physical and chemical structure of the follicular compartment, the decreased expression of TIMP in patients with PCOS may be part of a compensatory process to overcome the physical properties of the thick ovarian capsule.     

Human papilloma virus testing in patient follow-up post cone biopsy due to high-grade cervical intraepithelial neoplasia

OBJECTIVE: We evaluated the contribution of the human papilloma virus (HPV) load in planning follow-up and management of women post cone biopsy for high-grade cervical intraepithelial neoplasia (CIN2-3). METHODS: Ninety-six suitable women were followed-up by Pap smears: two consecutive abnormal smears dictated referral for colposcopy-directed biopsy. Before colposcopy, HPV tests determined high-risk HPV DNA type and load (Hybrid Capture System type I). Patients histologically diagnosed with CIN1 or CIN2-3 underwent repeat conization or hysterectomy for residual disease. HPV load was compared to cytology for the detection of residual disease. RESULTS: At follow-up, 20/89 (22.4%) studied women had positive cytology reports of either low- (n = 11) or high-grade (n = 9) squamous intraepithelial lesion (SIL). Colposcopic biopsies diagnosed 9 CIN1 and 8 CIN2-3 cases. Residual disease was corroborated in 16/17 (94.1%) women and the status was readjusted based on cone biopsy/hysterectomy: CIN2-3 in 9 and CIN1 in 7. The positive prediction values for CIN2-3 residual disease with high-grade SIL, CIN2-3 on colposcopic punch biopsy, and high HPV load were 89, 100, and 100%, respectively. For CIN1 residual disease with low-grade SIL, CIN1 on colposcopic punch biopsy, and low and borderline HPV load, they were 54.5, 77.7, and 100%. The HPV load was a more accurate predictor for CIN1 or CIN2-3 on the cervical specimen in cases with low-grade SIL or CIN1 on colposcopic biopsy. CONCLUSIONS: Evaluating HPV loads after a positive cytology report may assist in triaging women post conization biopsy for CIN2-3 to appropriate treatment. Its high positive predictive value, specificity, and sensitivity for CIN1 and CIN2-3 and supplementary information could be especially pertinent for clinical management of low-grade SIL cases.     

Analyzing Factors Affecting the Success Rate of Frozen–Thawed Embryos

PURPOSE: In recent years the infertile population applying for IVF treatments was changed and so the indications for performing intracellular sperm injection (ICSI). The aim of this study was to analyze predicting factors of our thawing cycles. METHODS: From December 1998 to July 2001, 440 consecutive thawing cycles were performed. Patient characteristics were examined. The number of cryopreserved embryos, number of transferred embryos, the timing of cryopreservation (48 h vs. 72 h), and embryo survival rate were analyzed as a possible predictor for pregnancies achievement. RESULTS: Conventional IVF patient's characteristic was significantly different from ICSI population and analysis has been performed for every population separately. In the IVF population the women age, the number of transferred embryos, and timing of cryopreservation were factors significantly influencing the pregnancy rate. Interestingly, in the ICSI population only the number of transferred embryos was found to be a predictive factor. CONCLUSION: ICSI and IVF cycles should be analyzed separately. Not all the factors influencing the success rate in the conventional IVF population are valid in the ICSI population.     

A system for monitoring the position and time of feet contact during walking

An analogue time/distance measurement for use in walking studies and based on foot contact is presented. The system utilizes a d.c.current source, feeding resistance wires bonded longitudinally to a walkway, and shorted by conducting strips on the shoe. An example of an application of the system is included: a comparison of the walking performance of an amputee with two different knee systems.     

Visual imagery of famous faces: effects of memory and attention revealed by fMRI

Complex pictorial information can be represented and retrieved from memory as mental visual images. Functional brain imaging studies have shown that visual perception and visual imagery share common neural substrates. The type of memory (short- or long-term) that mediates the generation of mental images, however, has not been addressed previously. The purpose of this study was to investigate the neural correlates underlying imagery generated from short- and long-term memory (STM and LTM). We used famous faces to localize the visual response during perception and to compare the responses during visual imagery generated from STM (subjects memorized specific pictures of celebrities before the imagery task) and imagery from LTM (subjects imagined famous faces without seeing specific pictures during the experimental session). We found that visual perception of famous faces activated the inferior occipital gyri, lateral fusiform gyri, the superior temporal sulcus, and the amygdala. Small subsets of these face-selective regions were activated during imagery. Additionally, visual imagery of famous faces activated a network of regions composed of bilateral calcarine, hippocampus, precuneus, intraparietal sulcus (IPS), and the inferior frontal gyrus (IFG). In all these regions, imagery generated from STM evoked more activation than imagery from LTM. Regardless of memory type, focusing attention on features of the imagined faces (e.g., eyes, lips, or nose) resulted in increased activation in the right IPS and right IFG. Our results suggest differential effects of memory and attention during the generation and maintenance of mental images of faces.     

Complicated Clinical Course and Poor Reproductive Outcomes of Women with Tubo-Ovarian Abscess after Fertility Treatments

Study Objective

To assess the clinical course and surgical and fertility outcomes of patients diagnosed with tubo-ovarian abscess (TOA) after fertility treatment.