Impact of video games on plasticity of the hippocampus.

The hippocampus is critical to healthy cognition, yet results in the current study show that action video game players have reduced grey matter within the hippocampus. A subsequent randomised longitudinal training experiment demonstrated that first-person shooting games reduce grey matter within the hippocampus in participants using non-spatial memory strategies. Conversely, participants who use hippocampus-dependent spatial strategies showed increased grey matter in the hippocampus after training. A control group that trained on 3D-platform games displayed growth in either the hippocampus or the functionally connected entorhinal cortex. A third study replicated the effect of action video game training on grey matter in the hippocampus. These results show that video games can be beneficial or detrimental to the hippocampal system depending on the navigation strategy that a person employs and the genre of the game.

Individual connectivity-based parcellations reflect functional properties of human auditory cortex.

Neuroimaging studies of the functional organization of human auditory cortex have focused on group-level analyses to identify tendencies that represent the typical brain. Here, we mapped auditory areas of the human superior temporal cortex (STC) in 30 participants by combining functional network analysis and 1-mm isotropic resolution 7T functional magnetic resonance imaging (fMRI). Two resting-state fMRI sessions, and one or two auditory and audiovisual speech localizer sessions, were collected on 3-4 separate days. We generated a set of functional network-based parcellations from these data. Solutions with 4, 6, and 11 networks were selected for closer examination based on local maxima of Dice and Silhouette values. The resulting parcellation of auditory cortices showed high intraindividual reproducibility both between resting state sessions (Dice coefficient: 69-78%) and between resting state and task sessions (Dice coefficient: 62-73%). This demonstrates that auditory areas in STC can be reliably segmented into functional subareas. The interindividual variability was significantly larger than intraindividual variability (Dice coefficient: 57%-68%, p<0.001), indicating that the parcellations also captured meaningful interindividual variability. The individual-specific parcellations yielded the highest alignment with task response topographies, suggesting that individual variability in parcellations reflects individual variability in auditory function. Connectional homogeneity within networks was also highest for the individual-specific parcellations. Furthermore, the similarity in the functional parcellations was not explainable by the similarity of macroanatomical properties of auditory cortex. Our findings suggest that individual-level parcellations capture meaningful idiosyncrasies in auditory cortex organization.

Laparoscope-assisted appendectomy in children: the two-trocar technique.

UNLABELLED: The conventional cannulae position in laparoscopic appendectomy does not permit good visualization of the appendix, especially if it is in a retrocaecal or pelvic position. In children, the smaller dimension of the peritoneal cavity aggravates this problem. METHOD: In order to optimize appendix visualization, we propose a modification of the cannulae position associated with extraabdominal appendectomy. Two trocars are inserted, one in the umbilicus under direct vision and one in the midline above the pubic symphysis. The telescope is inserted in the second cannula. The appendix is delivered via the umbilical trocar incision and a conventional appendectomy is performed. RESULTS: During a one-year period, 38 appendectomies were performed. In 29 cases (76.3 %) the technique was successful. In 9 patients (4 with peritonitis, 4 with a retrocaecal and one with a pelvic appendix) a third trocar was necessary to complete the operation. We had two conversions (5.2 %), one to open surgery and one to intraabdominal laparoscopic appendectomy. Mean operation time was 19 min. There were two infectious complications (one parietal and one intraabdominal). CONCLUSIONS: The excellent visualization permitted considerable time gain. Infectious complications were also low. This method is suggested as an alternative procedure for appendectomy, especially in children, because of their favorable anatomy.

[Sentinel surveillance of diarrhea in Ksar-Hellal (Tunisia)]. / Surveillance sentinelle de la diarrhée à Ksar-Hellal (Tunisie).

BACKGROUND: In order to simplify the national data collection related to diarrhea, a sentinel surveillance system was implemented in the Ksar-Hellal district (Tunisia). POPULATION AND METHODS: This system was based on 461 cases of diarrhea collected from health centers and hospitals between June 1994 and December 1995. RESULTS: The collected information confirmed the previous data provided by the national system: frequency of diarrhea in health centers (4.14%), occurrence of the disease especially in the summer period, rate of hospitalization (10%) and low proportion of severe dehydration. The system also gave some new information related to the proportion of persistent diarrhea (7.1%), the low frequency of malnutrition (11%) and the etiology. CONCLUSION: The sentinel surveillance system validates information previously provided by the National Surveillance System. It also gave new information not obtained by the classical surveillance system.

Obesity in relation to prostate cancer risk: comparison with a population having benign prostatic hyperplasia.

OBJECTIVE: To analyse the relationship between obesity and prostate cancer, when compared with men with benign prostatic hyperplasia (BPH). PATIENTS AND METHODS: The records were reviewed of consecutive patients with histologically confirmed prostate cancer admitted for prostate surgery between January 1993 and February 1999. Controls were selected from patients who were hospitalized at the same time for the surgical treatment of BPH. One control was matched to each case by age. Obesity was defined as a body mass index (BMI) of> 29 kg/m2. RESULTS: The study included 194 cases and 194 controls; their median (range) age at operation was 69.5 (50-88) years in both groups, and the BMI 26.1 (16.6-38.1) kg/m2 in the cancer and 25.7 (15.1-36.8) kg/m2 in the BPH group. The difference between the groups was not significant (P = 0.06). Obesity was significantly associated with prostate cancer, with an odds ratio (95% confidence interval) of 2.47 (1.41-4.34). Cases with advanced disease had a higher BMI than those with localized disease, but when age was considered the difference was not significant. CONCLUSION: In general the BMI was not significantly associated with prostate cancer when compared with men having BPH. However, obese men had 2.5 times the risk of having prostate cancer.