Curve Crossing Problem with Arbitrary Coupling: Analytically Solvable Model

We give a general method for finding an exact analytical solution for the two state curve crossing problem. The solution requires the knowledge of the Green's function for the motion on the uncoupled potential. We use the method to find the solution of the problem in the case of parabolic potentials coupled by Gaussian interaction. Our method is applied to this model system to calculate the effect of curve crossing on electronic absorption spectrum and resonance Raman excitation profile

Canine cerebrospinal fluid total nucleated cell counts and cytology associations with the prevalence of magnetic resonance imaging abnormalities

Timothy B Hugo, Kathryn L Heading, Robert H Labuc Melbourne Veterinary Specialist Centre, Glen Waverley, Vic, Australia Introduction: The combination of cerebrospinal fluid (CSF) analysis and magnetic resonance imaging (MRI) are often used to investigate intracranial disease in dogs. The aim of this retrospective study was to determine if the total nucleated cell count (TNCC) or cytology findings in abnormal CSF are associated with the prevalence of MRI abnormalities. Materials and methods: For each case, the TNCC was categorized into one of three groups: A (<25×106/L); B (25–100×106/L); and C (>100×106/L). Cytology findings were categorized by the predominant cell type as lymphocytic, monocytoid, neutrophilic, or eosinopilic. MRI descriptions were classified as either normal or abnormal, and abnormal studies were further evaluated for the presence of specific characteristics (multifocal or diffuse disease versus focal disease, positive T2-weighted hyperintensity, positive FLAIR hyperintensity, contrast enhancement, mass effect, and the presence of poorly or well-defined lesion margins). Results: Forty-five dogs met the inclusion criteria and MRI abnormalities were found in 29/45 (64%) dogs. TNCCs were not associated with the prevalence of MRI abnormalities or specific characteristics. Cytology categories were significantly associated with the prevalence of MRI abnormalities (P<0.001). Specifically, monocytoid cytology was 22.8 times more likely to have an abnormal MRI than lymphocytic cytology. CSF cytology was not significantly associated with specific abnormal MRI characteristics. Conclusion: There are minimal associations between CSF abnormalities and the prevalence of MRI abnormalities. These results support the continued importance of utilizing both tests when investigating intracranial disease. When CSF analysis must be performed initially, this study has demonstrated that an abnormal CSF with a monocytoid cytology supports the value of performing a brain MRI in dogs with evidence of intracranial neurological disease. Keywords: cerebrospinal fluid, magnetic resonance imaging, canine, total nucleated cell counts, cytolog

Diagnosis and management of non-erosive reflux disease - the Vevey NERD Consensus Group

Background/Aims: Although considerable information exists regarding gastroesophageal reflux disease with erosions, much less is known of non-erosive reflux disease (NERD), the dominant form of reflux disease in the developed world. Methods: An expert international group using the modified Delphi technique examined the quality of evidence and established levels of agreement relating to different aspects of NERD. Discussion focused on clinical presentation, assessment of clinical outcome, pathobiological mechanisms, and clinical strategies for diagnosis and management. Results: Consensus was reached on 85 specific statements. NERD was defined as a condition with reflux symptoms in the absence of mucosal lesions or breaks detected by conventional endoscopy, and without prior effective acid-suppressive therapy. Evidence supporting this diagnosis included: responsiveness to acid suppression therapy, abnormal reflux monitoring or the identification of specific novel endoscopic and histological findings. Functional heartburn was considered a separate entity not related to acid reflux. Proton pump inhibitors are the definitive therapy for NERD, with efficacy best evaluated by validated quality-of-life instruments. Adjunctive antacids or H2 receptor antagonists are ineffective, surgery seldom indicated. Conclusions: Little is known of the pathobiology of NERD. Further elucidation of the mechanisms of mucosal and visceral hypersensitivity is required to improve NERD management

Effect of aging on transpyloric flow, gastric emptying, and intragastric distribution in healthy humans - Impact on glycemia

The original publication is available at www.springerlink.comThe aims of this study were to evaluate (i) the relationship between transpyloric flow (TF) assessed by Doppler ultrasonography and scintigraphy, (ii) the effects of healthy aging on TF and gastric emptying (GE), and (iii) the relationship between the glycemic response to oral glucose and TF. Ten healthy "young" (7 M, 3 F) and 8 "older" (4 M, 4 F), subjects had simultaneous measurements of TF, GE, and blood glucose after a 600-ml drink (75 g glucose labeled with 20 MBq 99mTc-sulfur colloid) while seated. TF measured by ultrasound was measured during drink ingestion and for 30 min thereafter. GE was measured scintigraphically for 180 min after drink ingestion. Blood glucose was measured before the drink and at regular intervals until 180 min. During drink ingestion, TF was greater (P < 0.05) and GE faster (retention at 60 min: 70.8+/-3.3 vs. 83.8+/-4.6%; P < 0.05) in young compared to older subjects. There was no difference in fasting blood glucose between the two groups but the magnitude of the rise in blood glucose was greater in the young compared to the older subjects; (at 15 min 2.4+/-0.3 vs. 1.5+/-0.5 mmol/L; P < 0.05). In contrast, after 90 min blood glucose concentrations were higher in the older subjects. There were significant relationships between the early blood glucose concentration and both TF (e.g., at 15 min: r = 0.56, P < 0.05) and GE (e.g., at 15 min: r = -0.51, P < 0.05). In conclusion, the results of this study indicate that (i) TF is initially less, and GE slower, in older compared to young subjects; (ii) the initial glycemic response to oral glucose is related to TF; and (iii) measurements of TF by ultrasound and scintigraphy correlate significantly.Deirdre O'Donovan, Trygve Hausken, Yong Lei, Antonietta Russo, Jennifer Keogh, Michael Horowitz and Karen L Jone