Hypoxanthine uptake by skeletal muscle microvascular endothelial cells from equilibrative nucleoside transporter 1 (ENT1)-null mice: effect of oxidative stress.

Adenosine is an endogenous regulator of vascular tone. This activity of adenosine is terminated by its uptake and metabolism by microvascular endothelial cells (MVEC). The predominant transporter involved is ENT1 (equilibrative nucleoside transporter subtype 1). MVEC also express the nucleobase transporter (ENBT1) which is involved in the cellular flux of adenosine metabolites such as hypoxanthine. Changes in either of these transport systems would impact the bioactivity of adenosine and its metabolism, including the formation of oxygen free radicals. MVEC isolated from skeletal muscle of ENT1(+/+) and ENT1(-/-) mice were subjected to oxidative stress induced by simulated ischemia/reperfusion or menadione. The functional activities of ENT1 and ENBT1 were assessed based on zero-trans influx kinetics of radiolabeled substrates. There was a reduction in the rate of ENBT1-mediated hypoxanthine uptake by ENT1(+/+) MVEC treated with menadione or after exposure to conditions that simulate ischemia/reperfusion. In both cases, the superoxide dismutase mimetic MnTMPyP attenuated the loss of ENBT1 activity, implicating superoxide radicals in the response. In contrast, MVEC isolated from ENT1(-/-) mice showed no reduction in ENBT1 activity upon treatment with menadione or simulated ischemia/reperfusion, but they did have a significantly higher level of catalase activity relative to ENT1(+/+) MVEC. These data suggest that ENBT1 activity is decreased in MVEC in response to the increased superoxide radical that is associated with ischemia/reperfusion injury. MVEC isolated from ENT1(-/-) mice do not show this reduction in ENBT1, possibly due to increased catalase activity.

Population assessment of Acropora palmata (Scleractinia: Acroporidae): relationship between habitat and reef associated species / Evaluación poblacional de Acropora palmata (Scleractinia: Acroporidae): relación entre el hábitat y especies de arrecife asociados

Three decades ago, Acropora palmata was one of the main reef-building coral species throughout the Caribbean, forming an essential component of the structural complexity of shallow coral reef habitats. These colonies still provide microhabitats for settlement, food and shelter to many vertebrates and invertebrates. The recent decline of A. palmata has been followed by a significant loss in spatial heterogeneity and possibly in species diversity. Studies addressing whether dead and living stands of Acropora hold different fish and benthic assemblages are scarce. The status of Acropora colonies and their associated species were assessed in October 2012, at two reef zones of Cayo Sombrero, Venezuela. Visual censuses of fish abundance and the number of macrofaunal individuals were recorded for both live and dead zones. Living Acropora colonies had the lowest abundance (˂31%). In both zoned the fish community was dominated by damselfishes (˂53%) and wrasses (˂36%), the benthic macrofauna by peracarid crustaceans (˂40%) and polychaetes (˂38%). Fish and benthic communities were not correlated with the condition (live or dead) of the Acropora habitats; possibly branching structures provide the necessary shelter and protection no matter if they are dead or alive. More replication is necessary to test this unexpected result.

Hace tres décadas, Acropora palmata fue una de las principales especies de coral constructoras de arrecifes a lo largo del Caribe, formando un componente esencial de la complejidad estructural disponible en los hábitats arrecifales someros. Estas colonias todavía proveen microhábitats para el asentamiento, alimentación y refugio de muchas especies de vertebrados e invertebrados. El declive reciente de A. palmata ha sido precedido por una pérdida significativa de heterogeneidad espacial y se piensa que ésta reducción ha producido una disminución importante en la diversidad de especies. Los estudios señalan que las colonias muertas o vivas de Acropora que sostienen diferentes comunidades de bentos y de peces son escasas. El estado de las colonias de Acropora y sus especies asociadas fueron evaluadas en Octubre de 2012, en dos zonas arrecifales diferentes de Cayo Sombrero, Venezuela. Censos visuales de la abundancia de especies de peces y el número de individuos de la macrofauna fueron también registrados para ambas zonas, tanto vivas como muertas. Las colonias vivas presentaron la menor abundancia (˂31%). En ambos sitios la comunidad de peces fue dominada por los peces damiselas (˂53%) y lábridos (˂36%); la macrofauna bentónica por crustáceos peracáridos (˂40%) y poliquetos (˂38%). Las comunidades de peces y bentos no mostraron correlación con la condición (vivo o muerto) de los hábitats de Acropora; posiblemente las estructuras ramificadas proveen el refugio y protección necesario sin importar si están vivos o muertos. Una mayor replicación es necesaria para probar este resultado inesperado.

Werdnig-Hoffmann disease: report of the first case clinically identified and genetically confirmed in central Africa (Kinshasa-Congo).

Werdnig-Hoffmann Disease: Report of the first case clinically identified and genetically confirmed in Central Africa (Kinshasa-Congo): Type 1 spinal muscular atrophy (SMA1) or Werdnig-Hoffman disease is rarely described in black populations. We report on one black patient diagnosed in Kinshasa. This patient was referred to Paediatric consultation at the age of 5 months 1/2 with extreme hypotonia progressing since birth, severe muscular weakness in his trunk and proximal parts of the extremities, ASD type II, and repeated episodes of pulmonary infections. He died of severe respiratory failure at the age of 10 months. EMG analysis revealed motor neuron a defect without nerve conduction anomaly, suggesting the diagnosis of spinal muscular atrophy disease. The diagnosis of SMA1 was definitely confirmed by a quantitative PCR-based testing that demonstrated homozygous deletion of SMN1, the primary disease-causing gene for spinal muscular atrophy, while two normal SMN2 alleles were present. There was a history of similar clinical symptomatology in a patient's older brother, suggesting a familial involvement. To the best of our knowledge, this is the first documented Werdnig-Hoffman case ever reported from Central Africa people.

Myocardial contrast echocardiography yields best accuracy using quantitative analysis of digital data from pulse inversion technique: comparison with second harmonic imaging and harmonic power Doppler during simultaneous dipyridamole stress SPECT studies.

AIMS: This prospective study assesses the (1) feasibility of quantifying ultrasound myocardial perfusion studies based on the densitometric analysis of digital data and the (2) comparison of pulse inversion, second harmonic and harmonic power Doppler modalities with SPECT. METHODS AND RESULTS: Twenty-three patients with suspected ischaemic heart disease had i.v. injections of Tc-Sestamibi and Optison during a dipyridamole stress test for echocardiography in pulse inversion, second harmonic and harmonic power Doppler mode. Analysis was (a) visual by scoring and (b) quantitative by densitometry of digital data for background subtracted myocardial opacification (a.u.) and normalized contrast effect (%). In the nine control patients, myocardial opacification at stress was greater (P< or =0.002) than in the pathologic group (5. +/- 3.3 vs 2.6 +/- 2.5 a.u. in pulse inversion, 5.4 +/- 2.1 vs 2.4 +/- 1.8 in second harmonic and 7.1 +/- 3.7 vs 4.9 +/- 3.7 a.u. in harmonic power Doppler). In the pathologic group, normalized contrast effect decreased significantly during stress (23.7 +/- 18.8 to 11.3 +/- 10.8%, P<0.003) only in pulse inversion. Kappa values for patient based diagnostic agreement with SPECT were 0.75 by pulse inversion, 0.62 by second harmonic and 0.52 by harmonic power Doppler for quantitative analysis, and 0.51, 0.37 and 0.35 respectively, for visual assessment. CONCLUSION: Myocardial contrast echocardiography should be analysed using densitometry of digital data. The new technique pulse inversion demonstrates best agreement with SPECT data.

Spionidae (Annelida: Polychaeta) from the Parque Nacional Morrocoy, Falcón, Venezuela.

Five species of polychaetes (Spionidae) were found associated to Thalassia testudinum meadows in Parque Nacional Morrocoy, Venezuela. We included a guide for their identification and present range extensions for the Venezuelan coasts and Southern Caribbean Sea. The species are: Dipolydora socialis, Prionospio (Minuspio) cirrifera, P. (Prionospio) fallax, P. (P.) steenstrupi, and Spio pettiboneae.

Spionidae (Annelida: Polychaeta) from the Parque Nacional Morrocoy, Falcón, Venezuela

Five species of polychaetes (Spionidae) were found associated to Thalassia testudinum meadows in Parque Nacional Morrocoy, Venezuela. We included a guide for their identification and present range extensions for the Venezuelan coasts and Southern Caribbean Sea. The species are: Dipolydora socialis, Prionospio (Minuspio) cirrifera, P. (Prionospio) fallax, P. (P.) steenstrupi, and Spio pettiboneae.

Natural demodulation of two-dimensional fringe patterns. I. General background of the spiral phase quadrature transform.

It is widely believed, in the areas of optics, image analysis, and visual perception, that the Hilbert transform does not extend naturally and isotropically beyond one dimension. In some areas of image analysis, this belief has restricted the application of the analytic signal concept to multiple dimensions. We show that, contrary to this view, there is a natural, isotropic, and elegant extension. We develop a novel two-dimensional transform in terms of two multiplicative operators: a spiral phase spectral (Fourier) operator and an orientational phase spatial operator. Combining the two operators results in a meaningful two-dimensional quadrature (or Hilbert) transform. The new transform is applied to the problem of closed fringe pattern demodulation in two dimensions, resulting in a direct solution. The new transform has connections with the Riesz transform of classical harmonic analysis. We consider these connections, as well as others such as the propagation of optical phase singularities and the reconstruction of geomagnetic fields.

Total variation norm for three-dimensional iterative reconstruction in limited view angle tomography.

An iterative Bayesian reconstruction algorithm for limited view angle tomography, or ectomography, based on the three-dimensional total variation (TV) norm has been developed. The TV norm has been described in the literature as a method for reducing noise in two-dimensional images while preserving edges, without introducing ringing or edge artefacts. It has also been proposed as a 2D regularization function in Bayesian reconstruction, implemented in an expectation maximization algorithm (TV-EM). The TV-EM was developed for 2D single photon emission computed tomography imaging, and the algorithm is capable of smoothing noise while maintaining edges without introducing artefacts. The TV norm was extended from 2D to 3D and incorporated into an ordered subsets expectation maximization algorithm for limited view angle geometry. The algorithm, called TV3D-EM, was evaluated using a modelled point spread function and digital phantoms. Reconstructed images were compared with those reconstructed with the 2D filtered backprojection algorithm currently used in ectomography. Results show a substantial reduction in artefacts related to the limited view angle geometry, and noise levels were also improved. Perhaps most important, depth resolution was improved by at least 45%. In conclusion, the proposed algorithm has been shown to improve the perceived image quality.

[Syllidae (Polychaeta) from Thalassia testudinum beds at Morrocoy National Park (Venezuela)]. / Syllidae (Polychaeta) de praderas de Thalassia testudinum en el Parque Nacional Morrocoy (Venezuela).

A total of 40 species of syllids (Polychaeta: Syllidae) inhabiting Thalassia testudinum beds in Morrocoy National Park, Venezuela, belonging to 13 genera, are reported; 36 species are new for Venezuela: Branchiosyllis exilis, B. oculata, Eusyllis lamelligera, Exogone arenosa, E. breviantennata, E. naidinoides, E. naidina, E. parahomoseta mediterranea, Grubeosyllis clavata, G. heterocirra, Odontosyllis detecta, O. enopla, O. gibba, Opisthosyllis brunnea, Plakosyllis brevipes, Sphaerosyllis bilobata, S. glandulata, S. magnidentata, S. piriferopsis, S. riseri, S. longilamina, S. taylori, Syllis alosae, Syllis riojai, n. comb., S. beneliahui, S. broomensis, S. cornuta, S. corallicola, S. garciai, S. hyalina, S. lutea, S. mexicana, S. prolifera, S. sardai and Xenosyllis scabra.

[Contrast echocardiography]. / Kontrastechokardiographie.

The intravenous application of an ultrasound contrast agent induces enhanced display of blood in all its pathways. Within cardiology, this principle is mainly utilized for signal enhancement of color Doppler and spectral Doppler in order to improve quantification of congenital and acquired valvular lesions and also for improved endocardial delineation during stress tests and in the evaluation of LV function. The new domaine of myocardial perfusion imaging by contrast echocardiography, however, needed profound technical developments before realization of the clinical potential could even be conceived. These are based on the complex reactions of microbubbbles in the acoustic field in order to allow the sensitive and bubble specific display of intramyocardial contrast effects. The presently available acquisition techniques, second harmonic imaging and harmonic power Doppler, demonstrate significant improvements if compared to traditional fundamental 2-d echocardiography; however, they are still subjected to important limitations. There are many anatomical, physiological, and technical reasons for insufficient display of intramyocardial microbubbles, the most important one being attenuation. It is hoped that the most recently developed imaging modality, pulse inversion technique, allows the necessary diagnostic accuracy and reproducibility in myocardial perfusion imaging.

The impact of pleurodesis in malignant effusion on respiratory function.

Pleurodesis of malignant pleural effusion provides for a substantially better quality of life compared to onging exudation with the need for repeated evacuation of fluid. Successful pleurodesis leads to permanent cessation of fluid production as a result of the formation of fibrous adhesion between the lung and costal pleura which in theory, however, might restrict lung mobility. In patients with poor lung function, or with need for bilateral pleurodesis, the apprehension of further impairment of lung function often arises. The aim of this study was to evaluate the effects of pleurodesis on lung function. Therefore 10 patients with malignant pleurisy with very limited tumour were investigated. They were without radiological signs of tumour infiltration in the lung parenchyma, without visible tumour growth in the pleural space during thoracoscopy and had undergone a successful one-sided pleurodesis. Respiratory function tests were performed at different times, 1-102 months after pleurodesis. The assessment consisted of: static and dynamic spirometry, exercise testing with blood gas determination and radiospirometry. Spirometric values were slightly low, but in general within the reference limits. Blood gas determination showed no signs of alveolar hypoventilation. Radiospirometry showed a slight attenuation of activity in the treated lung but similar turnover of gas of the treated vs. the untreated side. The study showed that pleurodesis in malignant pleurisy has only minor impact on respiratory function.

Myocardial perfusion after coronary artery bypass surgery. A study using ectomographic myocardial scintigraphy and adenosine provocation.

A study was conducted to determine the time dependency of myocardial perfusion improvement after coronary artery bypass graft (CABG) surgery. Seventeen 3-vessel diseased patients (16 male, 1 female) scheduled for CABG surgery from a cardiac surgical and intensive-care unit were examined. Ten of the 17 patients returned for examination after 1 year. A titrated adenosine infusion was used to expose reversible ischemia. Tc99m-sestamibi was injected at rest and at maximum adenosine infusion rate, and isotope distribution was determined using ectomographic myocardial scintigraphy. Visually scored percent isotope uptake defect size and percent uptake reduction were assessed. It was found that resting isotope uptake defects were unchanged 1 h after surgery, increased in severity after 1 week, and after 1 year were 24% less than the preoperative scores (p < 0.01) and 55% less than after 1 week (p < 0.001). It was found that adenosine infusion induced a 57% increase in average defect score preoperatively (p < 0.001) but no increase postoperatively. No differences were seen between regions supplied by arterial or venous grafts. Isotope uptake defects increased between 1 h and 1 week after CABG surgery, and after 1 year the scores were less than those recorded preoperatively and after 1 week. Adenosine-induced reversible isotope uptake changes seen preoperatively were eliminated postoperatively in all vessel regions.

In-vitro human spermatozoa nuclear decondensation assessed by flow cytometry.

The process of sperm chromatin decondensation occurs when a spermatozoon enters an ovum. Protamine disulphide bonds are reduced to SH and the polycationic protamines combine with the polyanionic egg protein, nucleoplasmin, thus being stripped from DNA which then combines with histones. Defective chromatin decondensation will thus prevent further development of the male pronucleus. In this study human sperm samples were incubated in vitro at 28 degrees C (using a medium in which the polyanion, heparin, substitutes for nucleoplasmin and beta-mercaptoethanol for egg glutathione) for 10, 20 and 30 min before stopping the reaction with formalin (to 3.6%). The DNA of the fixed cells was stained with Acridine Orange by a one-step method and subjected to flow cytometry and data analysis, in which a zone characteristic of condensed chromatin is outlined on red-green fluorescence contour plots. After 20 min of incubation 97% of the control spermatozoa that were in the mature window (WIN M) had decondensed and moved out of this region. Defects in sperm decondensation were seen in four semen samples of the 20 that were tested. In cases where spermatozoa fail to produce a fertilized egg the cause may lie with defective chromatin quality, including failure of the sperm chromatin to decondense. The method described here is a simple procedure for detecting sperm samples containing such defective cells.

Comparison of SPECT and ectomography for evaluating myocardial perfusion with technetium-99m-sestamibi.

UNLABELLED: This study compared myocardial perfusion scintigraphy performed with ectomography to corresponding SPECT studies. METHODS: In a comparative study between SPECT and ectomography, 19 patients with suspected coronary artery disease were imaged under similar conditions. A two-day protocol using 99mTc-sestamibi was followed. In SPECT, 32 projection images were acquired by rotating the gamma camera detector through 180 degrees, from 45 degrees left posterior oblique to 45 degrees right anterior oblique. Short-axis view sections and polar tomograms were reconstructed. In ectomography, a 30 degrees slant-hole collimator was rotated through 360 degrees in front of a stationary detector to obtain 64 projection images with different projection directions. The gamma camera was orientated perpendicular to the long axis of the left ventricle; the orientation was determined from the SPECT examination. Short-axis section images through the projected conical volume were reconstructed using a two-dimensional filtered back projection technique. In a blind test, the relative diagnostic value and image quality of the two methods were evaluated by three independent observers assessing short-axis view sections and polar tomograms. An objective evaluation based on relative values in the polar tomograms was also performed. The interpretations were evaluated with analysis of variance. RESULTS: After injection during exercise, there was no significant difference between SPECT and ectomography. After injection at rest, visualization of the left ventricle was superior (p < 0.05) and influence of external activity was less (p < 0.005) in ectomography. The activity level within a perfusion defect was significantly lower (p < 0.05) and its extension significantly larger (p < 0.05) in ectomography than in SPECT. There was no difference between the diagnosis based on SPECT or ectomography. CONCLUSION: In myocardial perfusion imaging with 99mTc-sestamibi, ectomography provides information similar to that obtained with SPECT and can, therefore, be used clinically for evaluation of myocardial perfusion when the gamma camera is postitioned perpendicular to the long axis of the left ventricle.

Exercise and redistribution thallium-201 myocardial scintigraphy: changes in distribution qualitatively unaffected by previous infarction.

Eighteen patients with stable exertional angina pectoris were investigated by thallium-201 (201Tl) exercise and redistribution single photon emission computed tomography (SPECT) after coronary angiography. Eight of the patients had a previous myocardial infarct. Six patients had single-, eight double- and four triple-vessel disease. An exercise SPECT was acquired 10 min after the administration of isotope, injected 1-2 min before the termination of a symptom-limited exercise test. A redistribution SPECT was recorded 3 h later. 201Tl activity per pixel was compared between the exercise and redistribution SPECT in relative and absolute terms. For each patient there was a good correlation between activity per pixel in the redistribution SPECT and the corresponding pixels in the exercise SPECT (mean correlation coefficient 0.86 +/- 0.08), irrespective of the extent of coronary artery disease or presence of a previous infarction in the pixel region. Relative wash-out correlated to the degree of coronary artery stenosis (r = 0.48), but did not differ between infarcted and non-infarcted myocardial regions. A similar relationship was documented for pixels with visual 'refill' in the redistribution SPECT. This implies that most of the information in the redistribution SPECT was present already in the exercise SPECT. Thus, qualitative information of a similar kind is obtained from images acquired immediately after exercise and after 3-4 h of redistribution.

Positron emission tomography shows high specific uptake of racemic carbon-11 labelled norepinephrine in the primate heart.

(-)-Norepinephrine is the predominant neurotransmitter of the sympathetic innervation of the heart. Racemic norepinephrine was labelled with carbon-11 and injected i.v. into Cynomolgus monkeys. Five minutes after injection there was a more than tenfold higher radioactivity in the heart than in adjacent tissue. Pretreatment with the norepinephrine reuptake inhibitor desipramine reduced the uptake by more than 80%. The high specific uptake of racemic [11C]norepinephrine indicates that enantiomerically pure (-)-[11C]norepinephrine has promising potential for detailed mapping of the sympathetic innervation of the human myocardium.

Muscle blood flow during intermittent exercise: comparison of the microdialysis ethanol technique and 133Xe clearance.

1. Local skeletal muscle blood flow was monitored using the microdialysis ethanol technique and 133Xe clearance during intermittent isometric contractions (5 s on/10 s off) of the thigh at 0-60% of the maximal voluntary isometric contraction force. 2. A linear increase in blood flow over a 25-fold range was detected using both 133Xe clearance and the microdialysis ethanol technique. 3. The median correlation coefficient between percentage maximal voluntary isometric contraction force and the ethanol outflow/inflow ratio, a marker of blood flow, was r = -0.98 (-0.94 to -0.99) (median and range, n = 6). The corresponding correlation coefficient for 133Xe clearance was r = 0.97 (0.92-0.98), the correlation coefficient between the ethanol outflow/inflow ratio and 133Xe clearance being r = -0.92 (-0.89 to -0.94). 4. Dialysate glucose concentration, although affected by blood flow, was not always significantly correlated with blood flow changes (r = 0.70; 0.51-0.95). 5. It may be concluded that the ethanol technique provides a valid measure of changes in local skeletal muscle blood flow. The data furthermore show that a linear increase in thigh skeletal muscle blood flow exists during the studied protocol of intermittent isometric contractions.

Late thrombolysis followed by antithrombotic treatment in acute myocardial infarction: effect of therapy evaluated with thallium-201 SPECT.

Perfusion abnormalities and infarct size evaluated by thallium-201 SPECT after late thrombolysis followed by anti-thrombotic treatment in acute myocardial infarction were studied in 111 patients. Patients were prospectively randomized to a treatment group (n = 54) receiving streptokinase initiated 12-49 h after onset of symptoms, followed by heparin for at least 5 days and warfarin and dipyridamole for at least 3 months, or to a control group (n = 57) treated routinely without any of these drugs. Thallium-201 scintigraphy was performed within 3 months of follow-up in 40 (74%) of the patients in the treatment group and 46 (81%) in the control group. During a symptom-limited bicycle test the isotope was injected at peak exercise. SPECT was acquired 10 min later (exercise SPECT) and after 3 h (redistribution SPECT). A computerized quantitative analysis was performed. Defects were defined as regions with activity below 40% of the maximum. In the exercise SPECT defects were significantly smaller in the treatment group than among control patients (9 +/- 12% vs 15 +/- 15% of the left ventricle; P < 0.05). The difference was more apparent in patients with Q-wave than in those with non-Q-wave infarctions and the entire difference was accounted for by patients without a previous history of infarct or angina pectoris. There was no statistically significant difference in defect size in the redistribution SPECT (5 +/- 10% vs 9 +/- 11%, ns).(ABSTRACT TRUNCATED AT 250 WORDS)

Cardiac angiosarcoma: a case report.

Primary neoplasms of the heart are rare and difficult to diagnose prior to surgery, even with modern imaging techniques. Often, the tumors are diagnosed only at autopsy. Angiosarcoma is the most common malignant neoplasm. This disease is most commonly found in middle-aged men, and the tumor is most often located in the right atrium. It commonly causes blood flow abnormalities, extensively infiltrates cardiac structures, and may extend through the heart wall to involve adjacent structures. Metastatic spread at the time of diagnosis is common, and surgical mortality is high. We present a case of primary angiosarcoma involving the right ventricle of the heart. This tumor developed 6 months after the patient had undergone coronary artery bypass surgery. The patient was initially thought to have a massive thrombus within the right ventricle but at surgery was found to have a malignant neoplasm invading the myocardium. Subsequently, he was found to have pulmonary metastases. A debulking procedure was performed, and the patient was started on chemotherapy. Rather prompt improvement occurred after the debulking procedure, but subsequent studies have indicated progression of the pulmonary metastases despite ongoing chemotherapy.