Active Extrusion of Heinz Bodies in Drug-Induced Haemolytic Anaemia

S ummary . A patient with repeated episodes of sulphonamide-induced haemolytic anaemia is reported. The haemolytic episodes were associated with a high percentage of Heinz bodies which had the unique feature of being actively extruded from the erythrocytes. Detailed morphological and biochemical studies are outlined, but the basis for the tendency to form Heinz bodies remains unclear. It is suggested that the phenomenon of active extrusion may provide an alternative route, independent of the reticuloendothelial system, for the removal of Heinz bodies. The close resemblance between the active expulsion of the Heinz bodies and the physiological denucleation of the maturing erythroblast is noted and a similar mechanism postulated.     

The influence of adrenergic, dopaminergic, cholinergic and serotoninergic drugs on plasma prolactin levels in ovariectomized, estrogen-treated rats.

Levels of plasma prolactin were estimated in ovariectomized, estrogen-treated rats following the systemic administration of several neural blocking and stimulating drugs. Phenoxybenzamine, an alpha-adrenergic blocker, at high doses, increased plasma prolactin. Phenotlamine, another alpha-adrenergic blocker, and propranolol, a beta-adrenergic blocker, also increased prolactin but the responses were small and transient. Clonidine, an alpha-adrenergic stimulating drug, elevated prolactin levels whereas the beta-adrenergic stimulator isoproterenol had no effect. Dopaminergic blockade by pimozide increased levels of prolactin while stimulation of dopamine receptors by apomorphine decreased prolactin release. Atropine (a muscarinic chilinergic blocker), arecoline (a muscarinic stimulator) and nicotine (a nicotinic cholinergic stimulating drug) did not affect basal prolactin levels. Mecamylamine (a nicotinic blocker) produced a small transient elevation in plasma prolactin. Methiothepin, an alleged serotoninergic blocker, markedly increased prolactin secretion, as did serotonin. The data suggested the involvement of several neurotransmitters in the control of basal secretion of prolactin.     

COX-2-dependent cardiac failure in Gh/tTG transgenic mice

Gh is a GTP binding protein that couples to the thromboxane receptor (TP), but also functions as tissue transglutaminase II (tTG). A transgenic mouse model was generated in which Gh was overexpressed (GhOE) in ventricular myocytes under the control of the alpha-myosin heavy chain promoter. Heart rate was elevated and both blood pressure and left ventricular ejection fraction were depressed in GhOEs. Left ventricular mass was increased, consistent with genetic and ultrastructural evidence of hypertrophy. Fibrosis and apoptosis were also augmented. Survival declined disproportionately in older GhOEs. Cardiomyocyte expression of COX-2, thromboxane synthase (TxS), and the receptors for TxA2 (the TP), PGF2alpha (the FP), and PGI2 (the IP) were upregulated and urinary 8,12-iso-iPF2alpha-VI,2,3-dinor-6-keto-PGF1alpha and 2,3-dinor-thromboxane B2 were increased in GhOEs, reflecting increased lipid peroxidation and cyclooxygenase (COX) activation. Selective COX-2 inhibition, TP antagonism, and suppression of lipid peroxidation each rescued the cardiac phenotype. Infusion of an FP agonist exacerbated the phenotype, whereas administration of an IP agonist improved cardiac function. Directed cardiac overexpression of Gh/tTG causes both TG activation and increased TP/Gh-dependent signaling. The COX-2-dependent increase in TxA2 generation augments cardiac hypertrophy, whereas formation of PGI2 by the same isozyme ameliorates the phenotype. Oxidant stress may contribute, via regulation of COX-2 expression and/or ligation of the TP and the FP by isoprostanes. Gh/tTG activation regulates expression of COX-2 and its products may differentially modulate cardiomyocyte commitment to cell death or survival.     

The use of an implantable loop recorder in the investigation of unexplained syncope in older people

INTRODUCTION: Reveal is a patient activated implantable loop recorder device with an 18 month battery life now available to assist in the diagnosis of suspected syncope or arrhythmias. We present our experience using this device in older subjects referred to a dedicated falls and syncope clinic in whom usual clinical assessment had not satisfactorily identified an attributable diagnosis but where we still suspected a cardiovascular cause for syncope or falls. METHODS AND RESULTS: during the past 3 years 15 subjects (mean age 73 years, range 61-89 years) had Reveal implanted for symptoms of syncope alone (n=6; 40%) and unexplained falls (n=3; 20%) or symptoms of syncope and unexplained falls (n=6; 40%). Symptom duration was long (mean 48 months; range 4-200 months). Subjects had experienced significant morbidity, 6 subjects (40%) required A&E attendance or hospital admission and 4 (27%) experienced a fracture. Despite extensive and repeated investigations, which included 12-lead ECG, echocardiogram, 24-h ambulatory heart rate monitor, 24-h ambulatory blood pressure monitor, orthostatic blood pressure measurement, supine and erect carotid sinus massage, electroencephalogram, and passive and GTN head up tilt testing, the attributable diagnosis remained unexplained. Of the 15 subjects, 7 have activated the device at 4 (range 0-14) months after implantation. Bradycardia was identified in 3 and ventricular tachycardia in 1 subject. Two subjects did not activate the device during the 18 months it was in-situ. Four people had problems with device activation. This is comparable to rates noted using Reveal in younger subjects. CONCLUSION: Reveal offers additional diagnostic yield in complex elderly subjects with suspected cardiovascular causes of syncope or unexplained falls which have not been previously satisfactorily diagnosed despite extensive investigations.     

Progression of sleep disturbances in Parkinson’s disease: a 5-year longitudinal study

Journal of Neurology - Sleep disorders can occur in early Parkinson’s disease (PD). However, the relationship between different sleep disturbances and their longitudinal evolution has not...     

Effects of a 2-, 3- and 4-electrode stimulator design on current dispersion on the surface and into the limb during electrical stimulation in controls and patients with wounds

Electrical stimulation is a widely used modality in the field of physical therapy and exercise physiology. The most common method for the application of electrical stimulation is a two-electrode system where one electrode is the source and the other is a reference. However, recent studies report that a more effective delivery system can be achieved if more than two electrodes are used. In the present investigation, the circuitry to deliver electrical stimulation through a 2-, 3- or 4-electrode delivery system was designed. The system was evaluated by its ability to deliver current on the surface of the skin as well as deep into the quadriceps muscle in six control subjects and in and around wounds in six other subjects. The results of the experiments showed that much better depth of penetration was achieved in a 4-electrode system (one electrode was on the opposite side of the limb and three electrodes were on top of the limb) than in either a 2- or a 3-electrode delivery system. In non-wounded skin, given the same current from the stimulator, the current in the quadriceps muscle was found to be double with a 4-electrode versus a 2-electrode system. In wounds, this same finding was seen. Here, blood flow, an indicator of the effectiveness of electrical stimulation in wounds, was three times higher if a multi-channel stimulator was used versus a 2-channel stimulator. Thus a multi-channel electrical stimulation system is more effective than a 2-electrode system.     

Site‐directed zebrafish transgenesis into single landing sites with the phiC31 integrase system

Background: Linear DNA‐based and Tol2‐mediated transgenesis are powerful tools for the generation of transgenic zebrafish. However, the integration of multiple copies or transgenes at random genomic locations complicates comparative transgene analysis and makes long‐term transgene stability unpredictable with variable expression. Targeted, site‐directed transgene integration into pre‐determined genomic loci can circumvent these issues. The phiC31 integrase catalyzes the unidirectional recombination reaction between heterotypic attP and attB sites and is an efficient platform for site‐directed transgenesis. Results: We report the implementation of the phiC31 integrase‐mediated attP/attB recombination for site‐directed zebrafish transgenics of attB‐containing transgene vectors into single genomic attP landing sites. We generated Tol2‐based single‐insertion attP transgenic lines and established their performance in phiC31 integrase‐catalyzed integration of an attB‐containing transgene vector. We found stable germline transmission into the next generation of an attB reporter transgene in 34% of all tested animals. We further characterized two functional attP landing site lines and determined their genomic location. Our experiments also demonstrate tissue‐specific transgene applications as well as long‐term stability of phiC31‐mediated transgenes. Conclusions: Our results establish phiC31 integrase‐controlled site‐directed transgenesis into single, genomic attP sites as space‐, time‐, and labor‐efficient zebrafish transgenesis technique. The described reagents are available for distribution to the zebrafish community. Developmental Dynamics 242:949–963, 2013. © 2013 Wiley Periodicals, Inc.     

Hyperbaric oxygen therapy improves angiogenesis and bone formation in critical sized diaphyseal defects

Besides the use of autologous bone grafting several osteoconductive and osteoinductive methods have been reported to improve bone healing. However, persistent non‐union occurs in a considerable number of cases and compromised angiogenesis is suspected to impede bone regeneration. Hyperbaric oxygen therapy (HBO) improves angiogenesis. This study evaluates the effects of HBO on bone defects treated with autologous bone grafting in a bone defect model in rabbits. Twenty‐four New‐Zealand White Rabbits were subjected to a unilateral critical sized diaphyseal radius bone defect and treated with autologous cancellous bone transplantation. The study groups were exposed to an additional HBO treatment regimen. Bone regeneration was evaluated radiologically and histologically at 3 and 6 weeks, angiogenesis was assessed by immunohistochemistry at three and six weeks. The additional administration of HBO resulted in a significantly increased new bone formation and angiogenesis compared to the sole treatment with autologous bone grafting. These results were apparent after three and six weeks of treatment. The addition of HBO therapy to autologous bone grafts leads to significantly improved bone regeneration. The increase in angiogenesis observed could play a crucial role for the results observed. © 2015 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 33:513–520, 2015.