Size of monodispersed nanomaterials evaluated by dynamic light scattering: Protocol validated for measurements of 60 and 203nm diameter nanomaterials is now extended to 100 and 400nm.

In vivo fate of nanomaterials is influenced by the particle size among other parameters. Thus, Health Agencies have identified the size of nanomaterial as an essential physicochemical property to characterize. This parameter can be explored by dynamic light scattering (DLS) that is described in the ISO standard 22412:2008(E) and is one of the methods recognized by Health Agencies. However, no protocol of DLS size measurement has been validated over a large range of size so far. In this work, we propose an extension of validation of a protocol of size measurement by DLS previously validated with certified reference materials (CRM) at 60 and 203nm. The present work reports robustness, precision and trueness of this protocol that were investigated using CRM at 100 and 400nm. The protocol was robust, accurate and consistent with the ISO standard over the whole range of size that were considered. Expanded uncertainties were 4.4 and 3.6% for CRM at 100 and 400nm respectively indicating the reliability of the protocol. The range of application of the protocol previously applied to the size measurement of liposomes and polymer nanoparticles was extended to inorganic nanomaterial including silica nanoparticles.

[Porto-hepatic thrombosis, revealing paroxysmal nocturnal hemoglobinuria, followed by regression induced by heparin therapy]. / Double thrombose porte et hépatique révélatrice d'une hémoglobinurie paroxystique nocturne et régressive sous héparinothérapie.

Budd-Chiari syndrome with or without portal thrombosis occurring during paroxysmal noctural hemoglobinuria is a complication with poor prognosis. We report the case of a 17-year-old woman with a double portal and hepatic venous thrombosis revealing a paroxysmal noctural hemoglobinuria and regressive with heparin. Our case suggests that the early diagnosis of the thrombosis with ultrasonography and Doppler, and rapidly initiated anticoagulant treatment may improve the prognosis of this disease.

[Physiology and main implications of magnesium in osteo-articular pathology]. / Physiologie et principales implications du magnésium en pathologie ostéo-articulaire.

The role of magnesium in the constitution, metabolism and hormonal control of bone tissue can be deducted from what is known of its physiology. Magnesium deficiency may result in vitamin-D resistant hypocalcaemia or even biochemical signs of hypoparathyroidism, which only regress after the deficiency is corrected. Measurements of magnesium levels in blood and urine are justified when such abnormalities occur in patients with digestive disorders, predominantly alcoholism, liver diseases or malabsorption. In all other circumstances, magnesium therapy is very rarely indicated for osteo-articular diseases.

Highly confined ions store charge more efficiently in supercapacitors.

Liquids exhibit specific properties when they are adsorbed in nanoporous structures. This is particularly true in the context of supercapacitors, for which an anomalous increase in performance has been observed for nanoporous electrodes. This enhancement has been traditionally attributed in experimental studies to the effect of confinement of the ions from the electrolyte inside sub-nanometre pores, which is accompanied by their partial desolvation. Here we perform molecular dynamics simulations of realistic supercapacitors and show that this picture is correct at the microscopic scale. We provide a detailed analysis of the various environments experienced by the ions. We pick out four different adsorption types, and we, respectively, label them as edge, planar, hollow and pocket sites upon increase of the coordination of the molecular species by carbon atoms from the electrode. We show that both the desolvation and the local charge stored on the electrode increase with the degree of confinement.

Maternal hyperventilation and foetal hypocapnia in sheep.

1. In anaesthetized foetal lambs near term, hypocapnia induced by maternal hyperventilation abolished the rise of arterial pressure and femoral vasoconstriction caused by hypoxaemia. This is consistent with interaction of P(CO2) and P(O2) on the foetal aortic bodies.2. In immature lambs (0.6-0.77 of term) maternal hyperventilation caused a fall in foetal carotid P(CO2) commensurate with that in the maternal blood. In mature lambs (at 0.9 or more of term) the fall in foetal carotid P(CO2) was less than that in maternal blood, whether the foetus was exteriorized or in utero.3. The mean transplacental gradient for P(CO2) (maternal arterial-umbilical vascular), when the foetus was replaced with a mechanical pump recirculating foetal blood, was 6.3 mm Hg. This is attributed to placental CO(2) production, and is nearly half the mean P(CO2) gradient (maternal artery-foetal carotid) of about 14 mm Hg during normal maternal ventilation.4. The mean maternal-umbilical transcotyledonary venous gradients (avoiding vascular shunts through the myometrium and intercotyledonary chorion) were for P(CO2) 1.7 mm Hg and for P(O2) 13.4 mm Hg.5. Maternal hyperventilation (P(a, CO2) approximately 20 mm Hg) caused a small fall in mean foetal carotid P(O2) (5 mm Hg), which was readily reversible with no evidence of progressive acidaemia.

[Destructive non-tumoral osteoarthropathies of the shoulder]. / Les ostéoarthropathies destructrices non tumorales de l'épaule.

Destructive arthropathy of the shoulder is reviewed and the indications of total prothesis are briefly considered. It seems that the long term functional tolerance of destructive arthropathy of the shoulder is better than would be expected considering the radiological damage which is often substantial. The indications of shoulder prosthesis are dominated by rheumatoid polyarthritis and are infrequent in the other forms of these arthropathies.

[Plasma exchange in rheumatology. Technical problems, tolerance, indications]. / Les échanges plasmatiques en rhumatologie. Problèmes techniques, tolérance, indications.

Plasma exchange, used since 1979 in the treatment of severe rheumatoid arthritis, has been the subject of numerous publications in the recent years. According to data from a review of the literature and from our personal experience, this therapy cannot be advocated in the usual forms of rheumatoid arthritis. Because of the side-effects, the complicated technical equipment required and the short duration of therapeutic results, plasma exchange should, for the time being, be restricted to malignant forms of rheumatoid arthritis, polyvisceral exacerbations in lupus and scleroderma, and hyperviscosity syndromes in globulinopathies.

[Cauda equina syndrome and ankylosing spondylitis. Association with acromegaly. A myelographic and tomodensitometric study of the lumbar canal]. / Syndrome de la queue de cheval et spondylarthrite ankylosante. Association à une acromégalie. Etude myélographique et tomodensitométrique du canal lombaire.

Cauda equina syndrome is a rare neurological complication of ankylosing spondylitis. The specific myelographic and tomodensitometric anomalies are exemplified by the reported observation. This case is unusual by the moderation of the neurological manifestations, and especially by the absence of sphincteral disorders. The characteristic roentgenologic signs of ankylosing spondylitis are associated with a scalloped appearance of the lumbar spinal column and antecedent quiescent acromegaly.

[Treatment of severe or vasculitis associated forms of rheumatoid arthritis by plasma exchanges (author's transl)]. / Le traitement des formes graves et malignes de polyarthrite rhumatoïde par les échanges plasmatiques.

Five patients with typical seropositive rheumatoid arthritis were treated by plasma exchange. All patients had severe affections resistant to conventional treatment, while in four cases the disease involved extra-articular localizations: rheumatoid nodules (3 cases), polyneuritis (1 case), skin necrosis (1 case). Each patient received between 5 and 10 plasma exchanges over a period of 3 to 4 weeks. No major complications were observed. Immediate results were very good in all cases, as shown by absence of clinical expression of the arthritis, marked regression in extra-articular symptoms, and reduction in erythrocyte sedimentation rate without parallel alterations in rheumatoid factor levels. Improvement lasted for only a few weeks in 3 patients, in one case preceded by an acutely painful episode. In the remaining 2 cases, with associated vasculitis, improvement has been sustained for a period that now exceeds one year. Results are compared with those reported in the published literature, and the mode of action and indications for plasma exchange in rheumatoid arthritis discussed.

[Articular manifestations of Whipple's disease. A case of sacroiliitis and destructive coxopathy]. / Manifestations articulaires de la maladie de Whipple. Un cas avec sacro-iliite et coxopathie destructrice.

Whipple's disease is a systemic illness whose pathogenesis, which is still poorly understood, implies an infectious agent accessible to antibiotic therapy. The authors report a case which is made unusual by the manifold systemic manifestations, important eosinophilia and destructive nature of the joint lesions of the hips. The physiopathological mechanisms of ocular and cutaneous manifestations are considered. A dramatic improvement is obtained with tetracyclin.

[Superoxide dismutase and rheumatoid arthritis. Study of a series of 6 cases]. / Superoxyde dismutase et polyarthrite rhumatoïde. Etude d'une série de six cas.

The authors present a short series (6 cases) of serum positive rheumatoid arthritis, treated by I.M. injections (5 cases) or intra-articular injections (one case) of dismutase superoxide of bovine origin. The treatment was stopped in one case for local intolerance. Four cases treated for four months by the intramuscular route, were uninfluenced by the treatment, nor was the patient treated by the intra-articular route. The laboratory parameters (E.S.E., Rose Waaler reaction) were not modified. On the other hand, the lymphocyte fragility in culture was improved. The good tolerance of this compound in the laboratory will permit further trials in higher dosage.

Cyanide stimulation of the systemic arterial chemoreceptors in foetal lambs.

1. In foetal lambs, delivered by Caesarean section under light chloralose anaesthesia, injection of sodium cyanide into the left atrium or ascending aorta caused a rise of arterial pressure and femoral vasoconstriction. The response to 0.77 mg/kg was barely present at 0.6 of term; by 0.8 of term there was a large response to one third of this dose.2. The cardiovascular response to cyanide injection into the left atrium or ascending aorta was diminished either by section of the vagi or by carotid denervation, and was abolished by cutting both sets of nerves.3. Injection of sodium cyanide into both common carotids simultaneously caused a substantial cardiovascular response and often a respiratory effort, abolished by carotid denervation, whereas injection into a single carotid rarely caused an effect.4. It is concluded that the carotid chemoreceptors in mature foetal lambs can be excited by a stimulus of sufficient intensity, even though they do not respond to moderate hypoxaemia.

Hypoxaemia and aortic chemoreceptor function in foetal lambs.

1. In foetal lambs the effect of raising and lowering arterial P(O2) (by varying the O(2) content of the maternal inspired gas mixture) was studied in order to determine whether the systemic arterial chemoreceptors regulated the circulation.2. From 0.7 of term relative hypoxaemia (e.g. reducing carotid P(O2) from 40 to 20 mm Hg) caused a rise of arterial pressure and femoral vaso-constriction. These changes were unaffected or even increased by bilateral section of the nerves from the carotid sinus and body. They were abolished by section of the vagi or aortic nerves.3. It is concluded that in foetal lambs during the last third of gestation the circulation is under reflex control by the aortic chemoreceptors.