A method for drug infusion into the lateral median eminence and arcuate nucleus of sheep

The role of catecholamines in the control of the GnRH pulse generator is unclear as studies have relied on the use of peripheral or intracerebroventricular injections, which lack specificity in relation to the anatomical site of action. Direct brain site infusions have been used, however, these are limited by the ability to accurately target small brain regions. One such area of interest in the control of GnRH is the median eminence and arcuate nucleus within the medial basal hypothalamus. Here we describe a method of stereotaxically targeting this area in a large animal (sheep) and an infusion system to deliver drugs into unrestrained conscious animals. To test our technique we infused the dopamine agonist, quinpirole or vehicle into the medial basal hypothalamus of ovariectomised ewes. Quinpirole significantly suppressed LH pulsatility only in animals with injectors located close to the lateral median eminence. This in vivo result supports the hypothesis that dopamine inhibits GnRH secretion by presynaptic inhibition in the lateral median eminence. Also infusion of quinpirole into the medial basal hypothalamus suppressed prolactin secretion providing in vivo evidence that is consistent with the hypothesis that there are stimulatory autoreceptors on tubero-infundibular dopamine neurons. (C) 1997 Elsevier Science B.V.

Spontaneous tendon rupture in systemic lupus erythematosus: association with Jaccoud`s arthropathy

Tendon rupture has rarely been described in patients with systemic lupus erythematosus. From observation of three cases of Jaccoud`s arthropathy with tendon rupture, and considering that this arthropathy is more related to an inflammatory process of the tendon sheath than to synovitis per se, the intention of this study was to review the cases of tendon rupture in patients with systemic lupus erythematosus, in the hope of determining the frequency of Jaccoud`s arthropathy associated with this complication. Systematic review using MEDLINE, Scielo and LILACS databases (1966 to 2009) and the following keywords: systemic lupus erythematosus, tendon rupture, Jaccoud`s arthropathy. Secondary references were additionally obtained. Additionally, three Brazilian systemic lupus erythematosus patients who developed tendon rupture are described. Only 40 articles obtained fulfilled the previously established criteria. They were all case reports; the number of cases reported was 52 which, together with the three cases presented herein add up to 55 cases. Forty-six patients were women aged between 19 and 71 years, with a mean age of 40.1 +/- 12.4 years, and the average duration of the disease was 10 years. The most frequently observed rupture sites were the patellar and Achilles` tendons. While almost all patients described were on various doses of corticosteroids, 16 patients concomitantly had Jaccoud`s arthropathy (29%). In conclusion, the association between Jaccoud`s arthropathy and tendon rupture in systemic lupus erythematosus has been underestimated. As almost one-third of the systemic lupus erythematosus patients with tendon rupture also have Jaccoud`s arthropathy, this arthropathy may be recognized as risk marker for tendon rupture. Lupus (2010) 19, 247-254.

Ideal soliton environment using parametric band gaps

Simultaneous solitary wave solutions for laser propagation in nonlinear parametric media with up to (3 + 1) dimensions are proved to exist. The combination of the large dispersion of a Bragg grating and the strong nonlinearity of chi((2)) optical material results in stable behavior with short interaction distances and low power requirements. The solutions are obtained by using the effective mass approximation to reduce the coupled propagation equations to those describing a dispersive parametric nonlinear waveguide, and are verified by solving the complete set of coupled band-gap equations numerically.

Cumulative sedimentation analysis of Escherichia coli debris size

A new method to measure Escherichia coil cell debris size after homogenization is presented. It is based on cumulative sedimentation analysis under centrifugal force, coupled with Sodium Dodecyl Sulfate-Polyacrylamide Gel Electrophoresis (SDS-PAGE) analysis of sedimented proteins. The effects that fermentation and homogenization conditions have on the resulting debris distributions were investigated using this method. Median debris size decreased significantly from approximately 0.5 mu m to 0.3 mu m as the number of homogenization passes increased from 2 to 10. Under identical homogenization conditions, uninduced host cells in stationary phase had a larger debris size than exponential cells after 5 homogenizer passes. This difference was not evident after 2 or in passes, possibly because of confounding intact cells and the existence of a minimum debris size for the conditions investigated. Recombinant cells containing protein inclusion bodies had the smallest debris size following homogenization. The method was also used to measure the size distribution of inclusion bodies. This result compared extremely well with an independent determination using centrifugal disc photosedimentation (CDS), thus validating the method. This is the first method that provides accurate size distributions of E. coli debris without the need for sample pretreatment, theoretical approximations (e.g. extinction coefficients), or the separation of debris and inclusion bodies prior to analysis. (C) 1997 John Wiley & Sons, Inc.

Validation of plasma clearance of (51)Cr-EDTA in adult renal transplant recipients: comparison with inulin renal clearance

Plasma clearance of (51)Cr-EDTA ((51)Cr-EDTA-Cl) is an alternative method to evaluate glomerular filtration rate (GFR). This study aimed to investigate the concordance between (51)Cr-EDTA-Cl and renal inulin clearance (In-Cl) in renal transplant recipients as well to determine the repeatability of (51)Cr-EDTA-Cl in kidney donors. Forty four kidney recipients and 22 kidney donors were enrolled. Simultaneous measurements of (51)Cr-EDTA-Cl and In-Cl were performed. A single dose of 3.7MBq of (51)Cr-EDTA was injected and the plasma disappearance curve was created by taking blood samples at 2, 4, 6 and 8 h after injection. Bland and Altman statistical approach was used to quantify the agreement between In-Cl and (51)Cr-EDTA-Cl and to determine the better concordance between all possibilities of measure for the (51)Cr-EDTA-Cl. The mean of In-Cl was 44.5 +/- 17.9 ml/min/1.73 m(2). There was a positive correlation between In-Cl and all possible measurements of (51)Cr-EDTA-Cl. (51)Cr-EDTA-Cl with two samples taken at 4 and 8 h or at 4 and 6 h presenting the narrow limits of agreement and a difference (bias) of 2.8 and 2.7 ml/min, respectively. Two plasma sampling for (51)Cr-EDTA-Cl was a reliable method to measure GFR compared with In-Cl and comprises a suitable method to be used in kidney transplanted patients.

Pulsed quadrature-phase squeezing of solitary waves in chi((2)) parametric waveguides

It is shown that coherent quantum simultons (simultaneous solitary waves at two different frequencies) can undergo quadrature-phase squeezing as they propagate through a dispersive chi((2)) waveguide. This requires a treatment of the coupled quantized fields including a quantized depleted pump field. A technique involving nonlinear stochastic parabolic partial differential equations using a nondiagonal coherent state representation in combination with an exact Wigner representation on a reduced phase space is outlined. We explicitly demonstrate that group-velocity matched chi((2)) waveguides which exhibit collinear propagation can produce quadrature-phase squeezed simultons. Quasi-phase-matched KTP waveguides, even with their large group-velocity mismatch between fundamental and second harmonic at 425 nm, can produce 3 dB squeezed bright pulses at 850 nm in the large phase-mismatch regime. This can be improved to more than 6 dB by using group-velocity matched waveguides.

Midterm and long-term results of percutaneous endovascular treatment of venous outflow obstruction after pediatric liver transplantation

PURPOSE: To evaluate retrospectively the midterm and long-term results of percutaneous endovascular treatment of venous outflow obstruction after pediatric liver transplantation. MATERIALS AND METHODS: During a 9-year period, 18 children with obstruction of a hepatic vein (HV) or inferior vena cava (IVC) anastomosis underwent percutaneous transluminal angioplasty (PTA) with balloon dilation or stent placement in case of PTA failure after liver transplantation. Patients` body weights ranged from 7.7 kg to 42.6 kg (mean, 18.8 kg +/- 9). Potential predictors of patency were compared between balloon dilation and stent placement groups. RESULTS: Forty-two procedures were performed (range, 1-11 per patient; mean, 2). Technical and initial clinical success were achieved in all cases. Major complications included one case of pulmonary artery stent embolization and one case of hemothorax. Three children (25%) with HV obstruction were treated with PTA and nine (75%) were treated with stent placement. Three children with IVC obstruction (75%) were treated with PTA and one (25%) was treated with a stent. There were two children with simultaneous obstruction at the HV and IVC; one was treated with PTA and the other with a stent. Cases of isolated HV stenosis have a higher probability of patency with balloon-expandable stent treatment compared with balloon dilation (P < .05). Follow-up time ranged from 7 days to 9 years (mean, 42 months +/- 31), and the primary assisted patency rate was 100% when stent placement was performed among the first three procedures. CONCLUSIONS: In cases of venous outflow obstruction resulting from HV and/or IVC lesions after pediatric liver transplantation, percutaneous endovascular treatment with balloon dilation or stent placement is a safe and effective alternative treatment that results in long-term patency.

An isolated perfused human placental lobule model for multiple indicator dilution studies

We describe a method for multiple indicator dilution studies in the isolated perfused human placental lobule developed to investigate the relationships between changes in pressure and flow and solute clearance. A peripheral lobule of a human placenta is perfused with a tissue culture-based medium and the perfusate oxygen tension, arterial and venous pressures, pH and perfusion temperature continuously monitored by a computerized system. Flow rates are readily changed. Bolus injections of vascular, extracellular and water space markers, and study compounds can be made into either maternal or fetal circulations, and precisely timed outflow fractions can be collected with computer-controlled fraction collectors, allowing simultaneous determination of concentration-time profiles of each marker. (C) 1997 Elsevier Science Inc.

Model-Predicted Performance of Second-Trimester Down Syndrome Screening With Sonographic Prenasal Thickness

Objective. The purpose of this study was to estimate the Down syndrome detection and false-positive rates for second-trimester sonographic prenasal thickness (PT) measurement alone and in combination with other markers. Methods. Multivariate log Gaussian modeling was performed using numerical integration. Parameters for the PT distribution, in multiples of the normal gestation-specific median (MoM), were derived from 105 Down syndrome and 1385 unaffected pregnancies scanned at 14 to 27 weeks. The data included a new series of 25 cases and 535 controls combined with 4 previously published series. The means were estimated by the median and the SDs by the 10th to 90th range divided by 2.563. Parameters for other markers were obtained from the literature. Results. A log Gaussian model fitted the distribution of PT values well in Down syndrome and unaffected pregnancies. The distribution parameters were as follows: Down syndrome, mean, 1.334 MoM; log(10) SD, 0.0772; unaffected pregnancies, 0.995 and 0.0752, respectively. The model-predicted detection rates for 1%, 3%, and 5% false-positive rates for PT alone were 35%, 51%, and 60%, respectively. The addition of PT to a 4 serum marker protocol increased detection by 14% to 18% compared with serum alone. The simultaneous sonographic measurement of PT and nasal bone length increased detection by 19% to 26%, and with a third sonographic marker, nuchal skin fold, performance was comparable with first-trimester protocols. Conclusions. Second-trimester screening with sonographic PT and serum markers is predicted to have a high detection rate, and further sonographic markers could perform comparably with first-trimester screening protocols.

High Prevalence of Clarithromycin Resistance and cagA, vacA, iceA2, and babA2 Genotypes of Helicobacter pylori in Brazilian Children

We isolated 45 Helicobacter pylori strains from 217 child patients. Resistance to clarithromycin, metronidazole, amoxicillin, and tetracycline was detected in 27%, 13%, 4%, and 0% of strains, respectively. The A2143G mutation was the most prevalent (67%) among clarithromycin-resistant strains. In addition, strain genotyping revealed a significant association between gastritis severity and the simultaneous presence of cagA, vacA s1m1, iceA2, and babA2 genes.

Cardiopulmonary Effects of Matching Positive End-Expiratory Pressure to Abdominal Pressure in Concomitant Abdominal Hypertension and Acute Lung Injury

Background: To evaluate the cardiopulmonary effects of positive end-expiratory pressure (PEEP) equalization to intra-abdominal pressure (IAP) in an experimental model of intra-abdominal hypertension (IAH) and acute lung injury (ALI). Methods: Eight anesthetized pigs were submitted to IAH of 20 mm Hg with a carbon dioxide insufflator for 30 minutes and then submitted to lung lavage with saline and Tween (2.5%). Pressure x volume curves of the respiratory system were performed by a low flow method during IAH and ALI, and PEEP was subsequently adjusted to 27 cm center dot H(2)O for 30 minutes. Results: IAH decreases pulmonary and respiratory system static compliances and increases airway resistance, alveolar-arterial oxygen gradient, and respiratory dead space. The presence of concomitant ALI exacerbates these findings. PEEP identical to AP moderately improved oxygenation and respiratory mechanics; however, an important decline in stroke index and right ventricle ejection fraction was observed. Conclusions: Simultaneous IAH and ALI produce important impairments in the respiratory physiology. PEEP equalization to AP may improve the respiratory performance, nevertheless with a secondary hemodynamic derangement.

Chronic Rhinosinusitis in Allergic Asthmatic Patients: Radiography Versus Low-Dose Computed Tomography Evaluation

Objective. Chronic rhinosinusitis (CRS) is a risk factor for asthma exacerbations and is associated with greater clinical severity. Discrepancies may exist between CRS clinical diagnosis and data from paranasal sinus (PS) X-ray or computed tomography (CT) scans. The objective was to compare PS involvement using low-dose CT and plain X-ray in allergic asthmatic patients with rhinitis. Methods. Patients underwent PS radiography in the frontal and mentonian positions and low-dose CT consisting of six to eight coronal scans performed on the central region of the sphenoidal, ethmoidal, maxillary, and frontal sinuses. Possible results for each sinus were a normal aspect or the presence of mucosal thickening, opacification, and/or air-fluid level. Results. Eighty-five (93.4%) of 91 study patients had radiological changes on radiography or CT. In only six (6.6%) were both tests normal. The maxillary was the most involved sinus by both methods. Simultaneous PS abnormalities were observed in 40.5% on X-ray and 56.7% on CT. For the frontal, ethmoidal, and sphenoidal sinuses, the proportion of normal results differed significantly between X-ray and CT: 80.2% versus 89%, 76.9% versus 63.7% and 96.7% versus 70.3%, respectively (p <.05). Agreement was over 70% for the maxillary and frontal sinuses. CT also provided a better diagnosis of air-fluid level changes than X-ray. Conclusions. Low-dose CT significantly showed larger number of normal PS results and diagnosed more severe PS lesions. As the determination of true sinus severity lesion impacts in asthma control, low-dose CT may replace PS plain X-ray and conventional CT to support better clinical decisions.

Oral manifestations of inflammatory bowel disease: a review based on the observation of six cases

Inflammatory bowel disease (IBD) comprises two chronic, tissue-destructive, clinical entities: Crohn`s disease (CD) and ulcerative colitis (UC), both immunologically based. Bowel symptoms are predominant, but extra-intestinal complications may occur, including involvement of the oral cavity. Oral involvement during IBD includes several types of lesions: the most common are aphthae; uncommon lesions include, among others, pyostomatitis vegetans and granulomatous lesions of CD. Starting with a presentation of six patients with oral manifestations, which were crucial for the final diagnosis of IBD, a review on the subject is presented. Oral involvement in IBD may be previous or simultaneous to the gastrointestinal symptoms. However, in the majority of cases, bowel disease precedes the onset of oral lesions by months or years. In many patients, the intestinal symptoms may be minimal and can go undetected; thus, most authors believe that the bowel must be thoroughly examined in all patients with suspected IBD even in the absence of specific symptoms. Usually, the clinical course of oral lesions is parallel to the activity of IBD; therefore, oral manifestations are a good cutaneous marker of IBD.

Sleep-related changes in hemodynamic and autonomic regulation in human hypertension

Objectives The present study investigates the hemodynamic and autonomic regulation during sleep-awake transitions and across different sleep cycles in patients with essential hypertension. Methods Nineteen individuals free of sleep apnea (10 normotensive and nine hypertensive matched for age, sex, and body mass index) underwent a standard polysomnography, with simultaneous electrocardiography and beat-to-beat blood pressure monitoring (Portapres). All measurements were determined while awake (before and after sleep), as well as in the beginning and at end of the sleep cycle (first/last cycle of nonrapid and rapid eye movement stages). Results Systolic blood pressure was higher in hypertensives and exhibited a similar reduction to the normotensives ones in initial nonrapid eye movement sleep. This reduction was because of different mechanisms: a significant fall in cardiac output in normotensives, whereas in hypertensives was also dependent of a decrease in peripheral vascular resistance. Hypertensive patients presented lower heart rate variation and attenuated baroreflex sensitivity during sleep but not immediately before and after sleep. Spectral analysis suggested a higher sympathetic activity in the sleep stages in hypertension. Additionally, a progressive sympathetic predominance (final rapid eye movement> initial rapid eye movement and awake period postsleep> awake period presleep) was observed in both groups. Conclusion Hypertension is associated with depressed baroreflex sensitivity and increased sympathetic activation during sleep. The greater sympathetic predominance at the end of night (preceding the morning surge of sympathetic activity) could be implicated in the occurrence of cardiovascular events. J Hypertens 27: 1655-1663 (C) 2009 Wolters Kluwer Health vertical bar Lippincott Williams & Wilkins.

Concurreny based transition refinement for the verification of distributed algorithms

We suggest a new notion of behaviour preserving transition refinement based on partial order semantics. This notion is called transition refinement. We introduced transition refinement for elementary (low-level) Petri Nets earlier. For modelling and verifying complex distributed algorithms, high-level (Algebraic) Petri nets are usually used. In this paper, we define transition refinement for Algebraic Petri Nets. This notion is more powerful than transition refinement for elementary Petri nets because it corresponds to the simultaneous refinement of several transitions in an elementary Petri net. Transition refinement is particularly suitable for refinement steps that increase the degree of distribution of an algorithm, e.g. when synchronous communication is replaced by asynchronous message passing. We study how to prove that a replacement of a transition is a transition refinement.