Renal functional contrast-enhanced magnetic resonance imaging: evaluation of a new rapid-clearance blood pool agent (p792) in sprague-dawley rats

OBJECTIVES: The objective of the present study was to compare P792, a new rapid clearance blood pool agent characterized by negligible interstitial diffusion but unrestricted glomerular filtration, with Gd-DOTA in both qualitative and quantitative aspects of renal functional magnetic resonance imaging. MATERIALS AND METHODS: Dynamic imaging was performed with a fast T1-weighted gradient-echo sequence on a 1.5-T magnet in 25 Sprague-Dawley rats, after injection of 13 micromol Gd/kg-1 of P792 (n = 10), 100 (n = 10), or 50 micromol Gd/kg-1 of Gd-DOTA (n = 5). Signal-time curves from 6 regions of interest (ROIs), including renal parenchyma and contents, were analyzed. RESULTS: Qualitative analysis depicted a typical pattern of temporal enhancement as previously described with extracellular gadolinium chelates, including early and brief enhancement of the aorta, renal vessels and cortex, quickly followed by enhancement of the medulla and then renal pelvis. However, a decrease in signal intensity was noted in the inner medulla and the renal pelvis approximately 90 seconds after bolus injection, being more marked when using the full dose of Gd-DOTA. Curve analysis showed a similar vascular phase within each parenchymal ROI, confirmed by similar upslopes, which ranged from 0.015 +/- 0.007 to 0.019 +/- 0.005. Following this initial phase, T1-enhancement appeared greater and longer within the medulla and renal pelvis, and subsequently in the whole kidney ROI with P792 (time to maximal enhancement (sec)/ enhancement rate: 85.5 +/- 15.9/3.1 +/- 0.4) as compared with Gd-DOTA full (53.0 +/- 18.9/ 2.7 +/- 0.3) or half dosage (65.2 +/- 20.1/ 2.2 +/- 0.2). The subsequent decrease in signal intensity, characterized by a downslope during the minute following maximal enhancement, was faster with Gd-DOTA (0.006 +/- 0.002) as compared either to P792 or half dosage Gd-DOTA (0.003 +/- 0.001). CONCLUSIONS: Due to its physicochemical and pharmacokinetic properties, P792 allows the use of a reduced dosage of gadolinium, resulting in less T2* effect without compromising T1 enhancement. Thus, P792 appears suitable for renal functional MR imaging.     

Comparison of functional MR imaging guidance to electrical cortical mapping for targeting selective motor cortex areas in neuropathic pain: a study based on intraoperative stereotactic navigation

PURPOSE: To assess the concordance between data from functional MR imaging (fMRI) guidance and the intraoperative electrical cortical mapping (iCM) in targeting selective motor cortex areas in refractory neuropathic pain. METHODS: Twenty-one patients (11 women and 10 men; mean age, 55.6 years) with refractory central (ischemic, 8 cases) and neuropathic pain (trigeminal neuropathy, 6 cases; syrinx/amputation/plexus trauma, 7 cases) underwent surgery for the implantation of an epidural electrode for chronic motor cortex stimulation (MCS) with general anesthesia and a frameless neuronavigation system used for the image-guided targeting procedure. All patients were studied by preoperative fMRI and epidural iCM with somatosensory evoked potentials and motor cortex stimulodetection. fMRI investigated systematically motor tasks of both hands and that related to the somatic area (foot or tongue) affected by pain. fMRI data were analyzed with the Statistical Parametric Mapping99 software (initial analysis threshold [AT] corresponding to P < .001), registered in the neuronavigation system and correlated intraoperatively with iCM. Matching of fMRI and iCM was specifically examined, focusing the study on hand mapping. RESULTS: Concordance between contours of fMRI activation area and iCM in precentral gyrus (mean distance, 3.8 mm) was found in 20/21 patients (95%). Because precision of iCM was suboptimal in 7 patients, concordance for more restrictive values of the AT (P < .0001) was found in only 13 of these 20 patients. Concordance was not found in one patient, as result of image distortion and residual motion artifact. CONCLUSIONS: In this study, fMRI guidance provides information that matches those of an independent functional method. These data illustrate the functional accuracy of fMRI guidance for the operative targeting of selective motor cortex areas in neuropathic pain.     

Mini-review: Presentation of pathogen-derived antigens in vivo

Most intracellular pathogens induce robust T cell responses upon infection of mammalian hosts. In most cases, these T cell responses are protective and result in pathogen clearance. It is therefore important to determine how T cells are primed and how they differentiate into cytokine-secreting and/or cytotoxic effector cells. In contrast to B cells, which recognize soluble Ag, CD8(+) and CD4(+) T cells react to Ag-derived peptides bound to MHC I or MHC II molecules, respectively. Therefore, elucidating the mechanisms by which pathogen-derived Ag become available for presentation is necessary to understand how pathogens trigger T cell responses in vivo. Although many excellent reviews have focused on the mechanisms involved in Ag processing, very few have pointed to the specificity of host-pathogen interactions. In this respect, it should be noticed that these interactions are very different from one pathogen to another, and may result in the involvement of different cells and molecules. Because of space limitations, we have decided to focus this review on two intracellular pathogens--vaccinia virus and Listeria monocytogenes. We have chosen these two pathogens because they both induce a strong CD8(+) T cell response and because they have been extensively studied by both microbiologists and immunologists.     

Comparison of the effects of leuprorelin acetate and danazol treatments on serum CA-125 levels in women with endometriosis

OBJECTIVE: To investigate the effects of danazol and leuprorelin acetate on CA-125 levels during treatment for endometriosis. PATIENTS AND METHODS: Fifty women with laparoscopically diagnosed and treated endometriosis, and 50 women without pelvic disease as a control group. Following surgical treatment, 35 women with endometriosis were divided into two groups. The first group (20 women) received 200 mg danazol three times daily for 6 months; the second group (15 women) received 3.75 mg leuprorelin acetate depot every 28 days for 6 months. Serum CA-125 levels were measured before medical treatment, during the last 15 days of the 6-month treatment course, and 3 months after treatment. RESULTS: Serum CA-125 levels were significantly higher in women with endometriosis than in women in the control group. Before treatment, CA-125 levels in patients with stage III/IV endometriosis were significantly higher than those in stage I/II endometriosis. Six months of danazol or leuprorelin acetate depot treatment decreased serum CA-125 levels. Three months after stopping danazol, CA-125 levels remained significantly lower than pretreatment levels. On the other hand, 3 months after stopping leuprorelin acetate, CA-125 levels returned to pretreatment levels. CONCLUSIONS: (a) Danazol and leuprorelin acetate are equally effective in the treatment of endometriosis. (b) Moreover, the results support the view that the determination of CA-125 levels may assist in evaluating progress of endometriosis treatment.     

Increased poliovirus-specific intestinal antibody response coincides with promotion of Bifidobacterium longum-infantis and Bifidobacterium breve in infants: a randomized, double-blind, placebo-controlled trial

To determine whether the size of the intestinal bifidobacterial population can influence the immune response to poliovirus vaccination in infants, we set up a randomized, placebo-controlled trial. From birth to 4 mo, infants were given a fermented infant formula (FIF) or a standard formula (placebo). Bifidobacteria were quantified monthly in infant stools. Antipoliovirus IgA response to Pentacoq was assessed before and 1 mo after the second vaccine injection. Thirty infants were randomized, and 20 completed the study (nine in the placebo group and 11 in the FIF group). Fecal bifidobacterial level was significantly higher with the FIF group at 4 mo of age (p=0.0498). Furthermore, B. longum/B. infantis carriage was higher at 4 mo in the FIF group (p=0.0399). Antipoliovirus IgA titers increased after Pentacoq challenge (p <0.001), and the rise was significantly higher in the FIF group (p <0.02). Antibody titers correlated with bifidobacteria, especially with B. longum/B. infantis and B. breve levels (p <0.002). Infants who harbored B. longum/B. infantis also exhibited higher levels of antipoliovirus IgAs (p <0.002). In conclusion, the present results indicate that antipoliovirus response can be triggered with a fermented formula that is able to favor intestinal bifidobacteria. Whether this effect on the immune system is achieved through the bifidogenic effect of the formula (mainly through B. longum/B. infantis and B. breve stimulation) or directly linked to compounds (i.e. peptides) produced by milk fermentation remains to be investigated.     

Same-day discharge for selected patients undergoing combined nasal and palatal surgery for obstructive sleep apnea

To determine the safety of same-day discharge for patients who undergo combined nasal and palatal surgery for obstructive sleep apnea syndrome, we undertook a retrospective review and analysis of 2 groups of patients (total, 86 patients) who underwent such surgery. The patients with obstructive sleep apnea syndrome who underwent combined nasal and palatal surgery were considered for same-day discharge if they fulfilled the following postoperative criteria: sustained O2 saturation of 94% or greater on room air while asleep, no history of cardiopulmonary disease or diabetes mellitus, adequate oral analgesia and oral intake, hemostasis, and normal vital signs. Twenty-three patients met these criteria and were assigned to group 1. The remaining 63 patients were admitted overnight for monitoring and were assigned to group 2. The data collected included patient demographics, respiratory disturbance index, lowest O2 saturation, body mass index, and postoperative complications. The mean age, respiratory disturbance index, lowest O2 saturation, and body mass index for group 1 were 45.9 years, 36 events per hour, 84.9%, and 28.7 kg/m2, respectively. For group 2, the results were 48 years, 36.5 events per hour, 82%, and 32.5 kg/m2. There were no postoperative complications in group 1, and 3 in group 2. There were no incidents of airway compromise or cardiopulmonary events in the immediate postoperative period in either group. There were no readmissions for either group. We conclude that same-day discharge for patients who have undergone combined nasal and palatal surgery for obstructive sleep apnea syndrome is relatively safe in selected cases in which significant comorbid diseases are not present. These selected cases would have constituted a minority of the patients studied.     

Prognostic significance of wound infections following major head and neck cancer surgery: an open non-comparative prospective study

Objective We evaluated the incidence, risk factors and consequences of wound infection (WI) following major head and neck cancer surgery in an open non-comparative study.Patients and methods The study group, comprising 95 patients who underwent clean-contaminated procedures with opening of the upper aerodigestive tract for biopsy-proven squamous cell cancer, were studied over a 1-year period. Antibiotic prophylaxis was amoxicillin and clavulanic acid. More than 20 variables were prospectively recorded for each patient. The mean follow-up was 30 months.Main results The overall WI rate was 50.5% (48/95). Most pathogens isolated from samples were gram-negative rods. In univariate analysis, we found three risk factors for WI: alcohol consumption (P=0.07), a hypopharyngeal location (P=0.02) and laryngectomy stoma (P=0.01). WI were associated with postoperative fever (P=1.5×10^–11), postoperative antibiotic therapy (P=1.5×10^–5) and postoperative death (P=0.043). Patients without WI had a median postoperative hospital stay of 15 days compared with 29 days for those with WI (P<0.001). Healing of WI was achieved after a median time of 48 days. WI delayed postoperative radiation therapy in 21 out of 33 evaluable patients. But overall survival, and local and metastatic failures were similar with and without WI.Conclusions WI are associated with a heavy postoperative morbidity, but have no prognostic impact on cancer control.     

Minimal invasive endoscopic resection of a giant left atrial appendage aneurysm

We report a case of a 35-year-old male patient who presented with chronic atrial fibrillation secondary to a massive congenital left atrial appendage aneurysm. Minimal invasive endoscopic resection of the left atrial aneurysm with cryoablation was performed. The patient was discharged home in sinus rhythm.     

Are communication activities shaped by environmental constraints in reverberating and absorbing forest habitats?

In the dense vegetation of temperate or tropical forests, communication processes are constrained by propagation-induced modifications of the transmitted sounds. The presence of leaves, trunks and branches induces important sound reverberation and absorption leading to diminution of the signal energy as well as qualitative modifications. The aim of this paper is to briefly review the different strategies used by birds to manage with these constraints. At the emitter's level, an adapted emission behavior which takes into account both the physical heterogeneities of the forest environment and the temporal variations of the acoustic constraints, is especially useful to control the active space of signaling. The coding of information into acoustic parameters that have different susceptibility to propagation constraints is also of great interest. At the receiver's level, an adaptive reception behavior (listening post) and a great tolerance to sound degradation during the decoding process are the keys to an optimal communication process.