Reduced systemic vascular resistance is the underlying hemodynamic mechanism in nitrate-stimulated vasovagal syncope during head-up tilt-table test

AbstractBackgroundNitroglycerin (NTG) challenge during head-up tilt-table testing (HUTT) is often utilized to determine the etiology of unexplained vascular syncope. However, conflicting results concerning nitrate-induced hemodynamic changes during HUTT have been reported. The purpose of this study was to assess the determinants of presyncopal symptoms during NTG-stimulated HUTT.MethodsWe evaluated 40 patients with suspected vasovagal syncope. Beat-to-beat changes in blood pressure, heart rate (HR), cardiac index (CI), and systemic vascular resistance (SVR) during HUTT were measured with thoracic impedance cardiography and a plethysmographic finger arterial pressure monitoring device.ResultsNone of the 40 patients complained of presyncopal symptoms during passive HUTT. However, after the administration of NTG 28 patients showed presyncopal symptoms (NTG+ group) and the remaining 12 patients did not (NTG– group). HR, CI, and the stroke index did not significantly differ between the two groups, whereas mean arterial pressure and SVR were significantly lower in the NTG+ group.ConclusionsPresyncopal symptoms during NTG-stimulated HUTT are SVR mediated, not cardiac output mediated. This study challenges the conventional idea of a decrease in cardiac output mediated by NTG as the overriding cause of presyncopal symptoms during HUTT

Inorganic Arsenite Potentiates Vasoconstriction through Calcium Sensitization in Vascular Smooth Muscle

Chronic exposure to arsenic is well known as the cause of cardiovascular diseases such as hypertension. To investigate the effect of arsenic on blood vessels, we examined whether arsenic affected the contraction of aortic rings in an isolated organ bath system. Treatment with arsenite, a trivalent inorganic species, increased vasoconstriction induced by phenylephrine or serotonin in a concentration-dependent manner. Among the arsenic species tested—arsenite, pentavalent inorganic species (arsenate), monomethylarsonic acid (MMA(V)), and dimethylarsinic acid (DMA(V))—arsenite was the most potent. Similar effects were also observed in aortic rings without endothelium, suggesting that vascular smooth muscle plays a key role in enhancing vasoconstriction induced by arsenite. This hypercontraction by arsenite was well correlated with the extent of myosin light chain (MLC) phosphorylation stimulated by phenylephrine. Direct Ca(2+) measurement using fura-2 dye in aortic strips revealed that arsenite enhanced vasoconstriction induced by high K(+) without concomitant increase in intracellular Ca(2+) elevation, suggesting that, rather than direct Ca(2+) elevation, Ca(2+) sensitization may be a major contributor to the enhanced vasoconstriction by arsenite. Consistent with these in vitro results, 2-hr pretreatment of 1.0 mg/kg intravenous arsenite augmented phenylephrine-induced blood pressure increase in conscious rats. All these results suggest that arsenite increases agonist-induced vasoconstriction mediated by MLC phosphorylation in smooth muscles and that calcium sensitization is one of the key mechanisms for the hypercontraction induced by arsenite in blood vessels

Acute Appendicitis in Henoch-Schönlein Purpura : A Case Report

Common complications of Henoch-Schönlein purpura (HSP) that lead to surgical intervention include intussusception, perforation, necrosis, and massive gastrointestinal bleeding. Acute appendicitis is rarely seen as a complication of HSP. A seven-year-old boy was admitted for arthralgia, abdominal pain, hematochezia, melena, and purpuric rash on the lower extremities. On admission day abdominal ultrasonography was normal, but on day 5, he became pyrexial and developed right iliac fossa pain and tenderness with guarding. Ultrasonography showed distended appendix surrounded by hyperechoic inflamed fat. On exploration an acutely inflamed, necrotic appendix was removed and grossly there was an appendiceal perforation in the appendiceal tip. Microscopically some of the small blood vessels in the submucosa showed fibrinoid necrosis with neutrophilic infiltrations. The authors report the case of a child who developed acute perforative appendicitis requiring appendectomy while on treatment for HSP

The Relative Contributions of the Medial Sural and Peroneal Communicating Nerves to the Sural Nerve

The medial sural cutaneous nerve (MSCN) and peroneal communicating nerve (PCN) conjoin in the calf area to form the sural nerve (SN). In previous anatomic studies, there was unresolved debate as to the main contributor to the sural nerve, and the relative contributions of MSCN and PCN had not been studied. The purpose of this study is to determine their relative neurophysiologic contributions to the SN by nerve conduction study (NCS). A total of 47 healthy subjects (25 males and 22 females, mean age 29.6 ± 10.4 yrs, range 20-59 yrs) participated in the study. This study employed the orthodromic nerve conduction technique: stimulation at the ankle and recording at the mid calf (SN); specifically, we preformed stimulation at the mid calf (MSCN, PCN) and recording at 14 cm proximal to the middle of the popliteal fossa (MSCN) and fibular head (PCN). The onset and peak latencies (ms) were SN 2.3 ± 0.2 and 3.0 ± 0.2; MSCN 2.1 ± 0.2 and 2.8 ± 0.2; and PCN 2.1 ± 0.2 and 2.8 ± 0.2. The peak-to-peak amplitudes (µV) and areas (nVsec) of the SN, MSCN, and PCN were 9.7 ± 3.9, 7.0 ± 4.7, and 5.0 ± 3.2; and 7.2 ± 2.9, 5.7 ± 3.4, and 4.0 ± 2.4, respectively. The side-to-side difference was not statistically significant. The main contributor to the SN was found to be the MSCN. The relative contribution ratio of the MSCN to the PCN was 1.37:1 by amplitude and 1.42:1 by area. However, in 32.9% of the subjects, the contribution of the PCN was greater than that of the MSCN

Sammelrezension

1.) Hanft, Anke / Simmel, Annika (Hrsg.): Vermarktung von Hochschulweiterbildung. Waxmann Verlag: Münster, 2007. 192 S. ISBN 978-3-8309-1785-4. 2.) Bremer, Helmut: Soziale Milieus, Habitus und Lernen: Zur sozialen Selektivität des Bildungswesens am Beispiel der Weiterbildung. Juventa Verlag: Weinheim, 2007. 308 S. ISBN 978-37799-1585-0. 3.) Dust, Martin: 'Unser Ja zum neuen Deutschland': Katholische Erwachsenenbildung von der Weimarer Republik zur Nazi-Diktatur. Studien zur Bildungsreform, Bd. 49. Peter Lang: Frankfurt, 2007. 631 S. ISBN 978-3-631-55693-1. 4.) Gieseke, Wiltrud: Lebenslanges Lernen und Emotionen: Wirkungen von Emotionen auf Bildungsprozesse aus beziehungstheoretischer Perspektive. W. Bertelsmann Verlag: Bielefeld, 2007. 280 S. ISBN 978-3-7639-3331-0. 5.) Heuer, Ulrike / Siebers, Ruth: Weiterbildung am Beginn des 21. Jahrhunderts: Festschrift für Wiltrud Gieseke. Erwachsenenpädagogisches Institut Berlin e.V. Waxmann Verlag: Münster, 2007. 496 S. ISBN 978-3-8309-1811-0. 6.) Janetzko, Dietmar: Eigenlogik: Zur Rolle subjektiver Theorien bei der Bildungsmotivation. Waxmann Verlag: Münster, 2007. 188 S. ISBN 978-3-8309-1693-2. 7.) Kaiser, Arnim / Kaiser, Ruth / Hohmann, Reinhard (Hrsg.): Lernertypen - Lernumgebung - Lernerfolg: Erwachsene im Lernfeld. W. Bertelsmann Verlag: Bielefeld, 2007. 284 S. ISBN 978-3-7639-3560-4. 8.) Koerrenz, Ralf / Meilhammer, Elisabeth / Schneider, Käthe (Hrsg.): Wegweisende Werke zur Erwachsenenbildung. Verlag IKS Garamond: Jena, 2007. 613 S. ISBN 978-3-938203-51-4. 9.) Schiersmann, Christiane: Berufliche Weiterbildung: Lehrbuch. VS Verlag für Sozialwissenschaften: Wiesbaden, 2007. 272 S. ISBN 3-8100-3891-1. 10.) West, Linden / Alheit, Peter / Andersen, Anders Siig / Merill, Barbara (Hrsg.): Using Biographical and Life History Approaches in the Study of Adult and Lifelong Learning. European Perspectives European Studies in Lifelong Learning and Adult Learning Research, Vol. 2. Peter Lang Verlag: Frankfurt a. M., 2007. 310 S. ISBN 978-3-631-56286-4

Primary Cardiac Angiosarcoma Presenting With Cardiac Tamponade

Primary cardiac angiosarcoma is a very rare disease with a poor prognosis. We report a case of a patient with a primary cardiac angiosarcoma who presented with cardiac tamponade; the angiosarcoma was successfully resected surgically

Primary Cardiac Lymphoma Presenting With Atrioventricular Block

Primary cardiac lymphomas (PCL) are extremely rare. Clinical manifestations may be variable and are attributed to location. Here, we report on a case of PCL presenting with atrioventricular (AV) block. A 55 year-old male had experienced chest discomfort with unexplained dyspnea and night sweating. His initial electrocardiogram (ECG) revealed a first degree AV block. Along with worsening chest discomfort and dyspnea, his ECG changed to show second degree AV block (Mobitz type I). Computed tomography (CT) scan showed a cardiac mass (about 7 cm) and biopsy was performed. Pathologic finding confirmed diffuse large B-cell lymphoma. The patient was treated with multi-drug combination chemotherapy (R-CHOP: Rituximab, cyclophoshamide, anthracycline, vincristine, and prednisone). After treatment, ECG changed to show normal sinus rhythm with complete remission on follow-up CT scan