Hemodynamic provocation with acetazolamide shows impaired cerebrovascular reserve in adults with sickle cell disease.

Sickle cell disease is characterized by chronic hemolytic anemia and vascular inflammation, which can diminish the vasodilatory capacity of the small resistance arteries, making them less adept at regulating cerebral blood flow. Autoregulation maintains adequate oxygen delivery, but when vasodilation is maximized, the low arterial oxygen content can lead to ischemia and silent cerebral infarcts. We used magnetic resonance imaging of cerebral blood flow to quantify whole-brain cerebrovascular reserve in 36 adult patients with sickle cell disease (mean age, 31.9±11.3 years) and 11 healthy controls (mean age, 37.4±15.4 years), and we used high-resolution 3D FLAIR magnetic resonance imaging to determine the prevalence of silent cerebral infarcts. Cerebrovascular reserve was calculated as the percentage change in cerebral blood flow after a hemodynamic challenge with acetazolamide. Co-registered lesion maps were used to demonstrate prevalent locations for silent cerebral infarcts. Cerebral blood flow was elevated in patients with sickle cell disease compared to controls (median [interquartile range]: 82.8 [20.1] vs 51.3 [4.8] mL/100g/min, P<0.001). Cerebral blood flow was inversely associated with age, hemoglobin, and fetal hemoglobin, and correlated positively with bilirubin, and LDH, indicating that cerebral blood flow may reflect surrogates of hemolytic rate. Cerebrovascular reserve in sickle cell disease was decreased by half compared to controls (34.1 [33.4] vs 69.5 [32.4] %, P<0.001) and was associated with hemoglobin and erythrocyte count indicating anemia-induced hemodynamic adaptations. In total, 29/36 patients (81%) and 5/11 controls (45%) had silent cerebral infarcts (median volume of 0.34 vs 0.02 mL, P=0.03). Lesions were preferentially located in the borderzone. In conclusion, patients with sickle cell disease have a globally reduced cerebrovascular reserve as determined by arterial spin labeling with acetazolamide and reflects anemia-induced impaired vascular function in sickle cell disease. This study was registered at clinicaltrials.gov identifier 02824406.

Understanding the selective etching of electrodeposited ZnO nanorods.

ZnO nanotubes were prepared by selective dissolution of electrodeposited nanorods. The effect of solution pH, rod morphology, and chloride ion concentration on the dissolution mechanism was studied. The selective etching was rationalized in terms of the surface energy of the different ZnO crystal faces and reactant diffusion. The nanorod diameter and chloride concentration are the most influential parameters on the dissolution mechanism because they control homogeneous dissolution or selective etching of the (110) and (002) surfaces. Bulk solution pH only has an effect on the rate of dissolution. By accurate control of the dissolution process, the nanomorphology can be tailored, and the formation of rods with a thin diameter (10-20 nm), cavity, or ultra-thin-walled tubes (2-5 nm) can be achieved.

[Delayed diagnosis of Plasmodium falciparum in a soldier in Uganda: false-positive rapid diagnostic test associated with reduced repeats in pfhrp2]. / Retard de diagnostic d'un accès palustre à Plasmodium falciparum chez un militaire en Ouganda : négativité des tests de diagnostic rapide associée à un polymorphisme de l'antigène HRP2.

Rapid diagnostic tests (RDTs) are the best alternative for malaria diagnosis where a microscopic examination cannot be performed. We report here the first case of P. falciparum (false-negative) misdiagnosis in a soldier stationed in Uganda, associated with a reduced number of repeats in the P. falciparum histidine-rich protein 2 gene (pfhrp2). This gene was subsequently sequenced to determine the reason for the discordance between the RDT results and the later microscopic examination. Ten repeats of the type 2 motif AHHAHHAAD and four repeats of the type 7 motif AHHAAD were found. This isolate belongs to the group of non-sensitive parasites (<43 repeats) that are not detected by HRP2 RDTs. This inappropriate case management could have been fatal for the patient. This case confirms the problem of negative RDT results in isolated situations and of basing a therapeutic strategy on these negative results. Investigations should be conducted in Uganda and other areas of Africa to determine the presence and the geographical spread of parasites with pfhrp2 gene deletion to ensure the best performance of RDTs.

Antinociceptive and anti-inflammatory effects of the ethyl acetate stem bark extract of Bridelia scleroneura (Euphorbiaceae).

Bridelia scleroneura is a member of the Euphorbiaceae family. In folk medicine in Cameroon, the stem bark of this plant is used for relieving abdominal pain, contortion, arthritis and inflammation. In this study, the antinociceptive and anti-inflammatory activities of the ethyl acetate stem bark extract have been evaluated. The putative analgesic effect of the plant extract was examined in abdominal constriction, hot plate, formalin and on pain using tail immersion mouse models and in carrageenan-induced paw edema in rats. The extract (150-600 mg/kg) exhibited a dose-dependent analgesic effect (46.27-78.97%) in acetic acid-induced abdominal constriction in mice. B. scleroneura extract increased the pain latency of nociceptive response to thermal stimuli at the higher dose of 600 mg/kg. B. scleroneuna induced significant dose-dependent reduction of the nociception in both early and late phases of the formalin test. The extract at the dose of 300 mg/kg, increased significantly, by 63.70% and 52.01% the tail-immersion latency time, 1 and 2 h post-dosing. In the carrageenan test, B. scleroneura (150-600 mg/kg, p.o) had dose-dependent and significant effects at different time intervals. This behaviour was similar to indometacin (10 mg/kg) used as a standard drug. These results show that the ethyl acetate stem bark extract of B. scleroneura possesses peripheral and central analgesic properties as well as anti-inflammatory activity against acute inflammation processes, in support of the folk medicinal use of the plant.

Diode laser spectroscopy of the nu(8) band of the SF(5)Cl molecule.

Diode laser spectra of SF(5)Cl have been recorded in the nu(8) band region at a temperature of ca. 240 K, a pressure of 0.25 mbar and an instrumental bandwidth of ca. 0.001 cm(-1). Four regions have been studied: a first one in the P-branch (906.849-907.687 cm(-1)), a second one in the Q-branch (910.407-910.944 cm(-1)), and two other ones in the R-branch (913.957-914.556 and 917.853-918.705 cm(-1) ). The whole nu(1)/nu(8) dyad of SF(5)35Cl has been previously recorded in the group of Professor H. Burger in Wuppertal, thanks to a Fourier transform infrared spectrometer. These data have thus been combined with our diode laser ones in the aim of refining the analysis. We used an effective Hamiltonian developed up to the fourth order and a set of programs called C(4nu)TDS. One thousand three hundred and forty-six transitions for nu(1), 495 (FTIR: 351; diode laser: 144) transitions for nu(8), and 406 ground state combination differences have been assigned and fitted. A global fit has been obtained with a rms of 0.00081 cm(-1) for the nu(1) band, 0.0012 cm(-1) for the FTIR data of the nu(8) band, 0.00055 cm(-1) for the diode laser data of this same band, and 0.00064 cm(-1) for the ground state. It appears that more data (for instance, using a supersonic jet) are still necessary to obtain a completely satisfactory analysis of the nu(8) region.

Toxicity of cadmium, endosulfan, and atrazine in adrenal steroidogenic cells of two amphibian species, Xenopus laevis and Rana catesbeiana.

The effects of cadmium, endosulfan, and atrazine on corticosterone secretion and viability of adrenal cells of African clawed frog (Xenopus laevis) and bullfrog (Rana catesbeiana) were assessed in vitro using a new bioassay. The bioassay relies on stimulation with adrenocorticotropic hormone (ACTH), the endogenous secretagogue for corticosterone secretion, and with dibutyryl cyclic adenosine monophosphate (dbcAMP), an analogue of cAMP, to pinpoint the site of action of the xenobiotics within the steroidogenic cell. To compare the test toxicants according to their endocrine-disrupting potential, the lethal concentration needed to kill 50% of the cells:effective concentration of 50% (LC50:EC50) ratio was calculated, with LC50 as the concentration that kills 50% of the steroidogenic cells and the EC50 as the concentration that impairs corticosterone secretion by 50%. The higher the ratio, the higher the potential for endocrine disruption. Atrazine had no affect on cell viability and on corticosterone secretion in X. laevis, but its endocrine-disrupting potential was high in R. catesbeiana. The LC50:EC50 ratio for cadmium and endosulfan in X. laevis was 26.07 and 1.23, respectively, and for atrazine, cadmium, and endosulfan in R. catesbeiana it was 909, 41, and 3, respectively. The dbcAMP did not restore corticosterone secretion in the cells exposed to the test toxicants in both species. Our study suggests that the secretory capacity of adrenal cells of amphibians can be impaired by environmental chemicals, especially atrazine in the bullfrog, and that these adrenotoxicants disrupt the enzymatic pathways leading to corticosterone secretion downstream from the step-generating cAMP.

Modulation of protein kinase C (PKC)-mediated contraction and the possible role of PKC epsilon in rat mesenteric arteries.

he involvement of protein kinase C (PKC) in isometric tension development of rat mesenteric arteries was investigated. Non-selective inhibition of PKC and selective inhibition of the epsilon isoform were performed using the PKC inhibitor, chelerythrine, and non-viral gene-transfer of a kinase inactive mutant of PKCepsilon (PKCepsilon-KN), respectively. Chelerythrine (2.5 or 5.0 microM) significantly and equally attenuated phenylephrine-induced but not potassium-induced contractions. Higher concentrations of chelerythrine (10 microM) caused the vessels to lose responsiveness to both phenylephrine and potassium chloride. Transfection of blood vessels with epsilon-KN also resulted in significant attenuation of contractile responses to phenylephrine. Potassium chloride-induced responses were not altered in transfected arteries. In a separate group of vessels, the relationship between [Ca2+]i and isometric tension was evaluated. These studies suggested that calcium sensitivity of the contractile apparatus was decreased in vessels when PKC-epsilon activity was compromised. The results of the study suggest that PKC-epsilon can modulate phenylephrine-induced contraction in mesenteric arteries via calcium-independent pathways.

Reaction of cyclohexanone benzylimines with ethylidenemalonate diesters. Diphenyl 2-ethylidenemalonate: a highly electrophilic synthetic equivalent of crotonic esters.

The diastereoselective Michael alkylation of alpha-substituted and alpha,alpha'-disubstituted cyclohexanone benzylimines with ethylidenemalonate diesters was carried out for mechanistic and synthetic purposes. In the first case, an inverse regioselectivity occurred in comparison with what is generally observed since the Michael adducts resulted from alkylation of the non substituted enamine tautomer. With alpha,alpha'-disubstituted imines, in all cases, the stereochemistry of the major diastereomer was the one anticipated from a mechanism including a chairlike complex approach with a preferred exo position for the beta-methyl group of the ethylidenemalonic acid diesters. Furthermore, diphenyl 2-ethylidenemalonate 4 was found to be a highly electrophilic synthetic equivalent of crotonic esters.

[Cognitive and emotional disorders in multiple sclerosis. Can a management strategy be envisioned?]. / Troubles cognitifs et émotionnels dans la sclérose en plaques. Peut-on envisager une stratégie de prise en charge?

There is a lack of precise data concerning the natural history of cognitive disorders in multiple sclerosis (MS), but recent neuropsychological studies have demonstrated that the incidence of such disorders in MS appears to be frequent (40-65% of cases), and have shown in particular that recent memory, conceptual reasoning, attention, executive functions, visuospatial perception and information processing speed are negatively affected. In contrast, language functions, general intelligence and implicit memory appear to be relatively well preserved. Although the presence and the degree of cognitive disorders does not seem to be directly linked to disease duration or to the extent of physical disability, the relationship between cognitive decline and brain lesions detected by magnetic resonance imaging (MRI) is still a subject of discussion. The prevalence of emotional and affective disorders is difficult to estimate. Their frequency has only rarely been investigated, and the lack of data on the natural history of these disorders and those factors which they have in common (the psychosocial consequences of this chronic and disabling disease, cognitive impairment, and brain lesions) further complicate the determination of treatment strategy. The adoption of appropriate strategies could limit the negative impact of this disease on the social functioning of MS patients.

Absence of cognitive impairment at long-term follow-up in adolescents treated with ECT for severe mood disorder.

OBJECTIVE: Cognitive functions of adolescents treated with ECT for mood disorder were evaluated at long-term follow-up. METHOD: At an average of 3.5 years (SD=1.7) after the last ECT, 10 subjects treated during adolescence with bilateral ECT for severe mood disorder completed a clinical and cognitive evaluation, including the California Verbal Learning Test and Squire's Subjective Memory Questionnaire. The same assessments were given to 10 psychiatric comparison subjects matched for sex, age, and diagnosis. RESULTS: All cognitive test scores of the patients treated with ECT were similar to those of the comparison subjects and did not differ from norms from the community. Six of the 10 ECT-treated patients reported having had memory losses immediately after the ECT course, but only one complained of subjective memory impairment at follow-up. CONCLUSIONS: The results suggest that adolescents given ECT for severe mood disorder do not suffer measurable cognitive impairment at long-term follow-up.

Fluorescence-imaging assay for cytotoxic plaque formation and for growth toward confluency of adherent cells.

A nondestructive fluorescence-imaging assay is described for quantitating the number and size of plaques formed over time by cytotoxic effector cells in a monolayer of target cells. It can also be used to assay the growth of adherent cells toward confluence. The method involves the use of fluorescein conjugated to high molecular weight dextran. The dextran is excluded by adherent cells, thereby making the medium around cells more fluorescent than the cells themselves. The area of the plate that is fluorescent can be determined by confocal fluorescence imaging microscopy. With this new method, changes in the confluency of adherent cells or in the number and area of cytotoxic plaques can be assayed repeatedly over an extended period of time, without manipulation of the cells or of the medium.

Novel triterpenoids suppress inducible nitric oxide synthase (iNOS) and inducible cyclooxygenase (COX-2) in mouse macrophages.

We have synthesized more than 80 novel triterpenoids, all derivatives of oleanolic and ursolic acid, as potential anti-inflammatory and chemopreventive agents. These triterpenoids have been tested for their ability to suppress the de novo formation of two enzymes, inducible nitric oxide synthase (iNOS) and inducible cyclooxygenase (COX-2), using IFN-gamma-stimulated primary mouse macrophages or lipopolysaccharide (LPS)-activated RAW 264.7 macrophages as assay systems. Two synthetic oleananes, 3,12-dioxoolean-1-en-28-oic acid (TP-69) and 3,11-dioxoolean-1,12-dien-28-oic acid (TP-72), were highly active inhibitors of de novo formation of both iNOS and COX-2. Both TP-69 and TP-72 blocked the increase in iNOS or COX-2 mRNA induced by IFN-gamma or LPS. In addition, TP-72 suppressed NF-KB activation in primary macrophages treated with the combination of IFN-gamma and LPS or IFN-gamma and tumor necrosis factor. The 3-alpha(axial)-epimer of ursolic acid suppressed de novo formation of COX-2, in contrast to naturally occurring 3-beta(equatorial)-ursolic acid. Inhibitory effects of TP-69 or TP-72 on iNOS formation were not blocked by the glucocorticoid receptor antagonist RU-486, indicating that these triterpenoids do not act through the glucocorticoid receptor, nor does TP-72 act as an iNOS or COX-2 enzyme inhibitor when added to RAW cells in which synthesis of these two enzymes in response to LPS has already been induced. It may be possible to develop triterpenoids as useful agents for chemoprevention of cancer or other chronic diseases with an inflammatory component.

[Clinical, biological and neuroradiological aspects of Sneddon's syndrome: 26 cases]. / Aspects cliniques, biologiques et neuroradiologiques du syndrome de Sneddon: 26 observations.

Sneddon syndrome is characterized by the association of livedo reticularis and cerebrovascular ischemic events. Clinical and MRI aspects are described in 26 patients with Sneddon syndrome. MRI features were classified in 6 groups according to the aspect and topography of the lesions. No correlation was found between the presence of vascular risk factors, valvulopathy or antiphospholipid antibodies and the presence of dementia or MRI lesions. There was a significant correlation between MRI extension of the lesions and clinical disability. Clinical course and MRI findings are presented according to the treatment.

Increased inhibition of proliferation of human B cell lymphomas following ligation of CD40, and either CD19, CD20, CD95 or surface immunoglobulin.

Non-Hodgkin's (NHL) B cell lymphomas are growth-inhibited by ligation of their CD40 molecules. This inhibition is not absolute in that approximately 50% of the cells are not inhibited. We conducted studies to see if other signals that have been reported to inhibit B cell lymphoma growth could be used in combination with anti-CD40 signaling to completely inhibit growth. Ligation of surface immunoglobulin (Ig), CD19, CD20, CD37 or CD95 with soluble antibody did not affect growth of the panel of NHL cells examined. Ligation of CD20, CD19 or CD95 was inhibitory for some NHL cell lines if the primary antibody was crosslinked with a secondary antibody. Combining anti-CD40 with anti-CD19, anti-CD20, or anti-Ig resulted in increased inhibition past that produced by anti-CD40 alone. The additive effect of anti-CD40 and other antibodies to selected surface markers was not observed in all NHL cell lines. Crosslinking of CD95 was also growth inhibitory for the majority of the NHL, and when combined with anti-CD40 under conditions that afforded crosslinking of the two receptors, increased inhibition was seen in three of the NHL cell lines. We found that cAMP or sodium butyrate (NaB) were also effective at inhibiting growth of the NHL cells; this was a profound inhibition (approaching 100%) compared to the 50% inhibition seen with anti-CD40 treatment. The potential for anti-CD40 and either cAMP or NaB to be additive was tested and not found to be the case. The ability to inhibit proliferation of the NHL was very dynamic with some antibody combinations being either inhibitory for multiple cells, not having an effect at all, or in some cases being stimulatory. This suggests that the NHL may represent unique stages of B cells that might serve as a model system which could be developed to precisely categorize patient NHL.

Anti-body-dependent cellular cytotoxicity (ADCC) function of peripheral blood polymorphonuclear neutrophils (PMN) after autologous bone marrow transplantation (ABMT).

Rapid recovery of the number and function of polymorphonuclear neutrophils (PMN) is critical to recovery from bone marrow transplantation. Although it is relatively easy to measure PMN number recovery, the evaluation of the functional recovery of these cells has not been adequately examined. The ability of peripheral blood PMNs to perform antibody-dependent cellular cytotoxicity (ADCC) was assessed in 25 patients undergoing autologous bone marrow transplantation (ABMT). PMNs were evaluated at a single cell level for ADCC function as measured by their ability to form plaques in antibody-sensitized ox erythrocyte (oxE) monolayers. The PMNs demonstrated low or absent ADCC function in the first week after completion of high-dose chemotherapy, regardless of primary diagnoses or myeloablative regimens. Although recovery to a neutrophil count of 500/microliters was prolonged in patients with AML (mean 40.2 days; range 25-67 days), functional activity of PMNs appeared much earlier (mean 19.6 +/- 6.1 days; range 2-65 days) in this group of patients compared to the group of patients with other diagnoses in which recovery to a neutrophil count of 500/microliters and the recovery of functional activity of PMNs occurred at roughly the same time. This single cell assay provided a useful method for determining ADCC functional ability of recovering PMNs post-BMT since few cells were required for each assay. This approach may also be useful in determining optimal timing of immune therapies post-ABMT, relying on myeloid cells as effector cells.

The effect of recombinant human interleukin-3 and recombinant human granulocyte-macrophage colony-stimulating factor on Fc gamma receptor expression and antibody-dependent cellular cytotoxicity of hematopoietic progenitor cells during in vitro myeloid maturation.

Enriched progenitor cell fractions from human bone marrow were induced to undergo myeloid maturation in culture using recombinant human interleukin-3 (rhIL-3) and granulocyte-macrophage colony stimulating factor (rhGM-CSF). A negative selection method using the murine monoclonal antibodies (MABs) PM81 (anti-CD15), AML-2-23 (anti-CD14), PC251 (anti-CD33), OKT11 (anti-CD2), and SCCL-1 (anti-CD71) and immunomagnetic beads coated with sheep anti-mouse IgG (Dynal A.S., Oslo, Norway) was used to remove the more mature cellular components of mononuclear cells from normal donor bone marrow samples. The resulting fraction of cells contained 35 to 40% CD34-positive cells, and less than 1% of cells expressed the receptors for the constant portion of immunoglobulin G Fc gamma RI or Fc gamma RII. A small population (3-5%) expressed Fc gamma RIII on day 0, and these cells were found by two-color flow cytometry to be primarily natural killer (NK) cells. The level of Fc gamma R expression was determined every 2 to 3 days on aliquots of the differentiating cells. Thirteen percent of the cultured bone marrow cells expressed Fc gamma RII after 48 hours in liquid culture with rhIL-3 and rhGM-CSF. The percent of cells expressing Fc gamma RII increased to a peak of 78% of the gated population on day 10. The mean fluorescence intensity (MFI) remained low for the first 8 to 10 days of culture, but at that time the MFI more than doubled. Fc gamma RI and Fc gamma RIII expression remained low throughout the culture period. The ability of the differentiating cells to perform antibody-dependent cellular cytotoxicity (ADCC) was determined at a single-cell level in a modified plaque assay using monolayers of ox erythrocyte (oxE) target cells. The purified progenitor cells, when placed in oxE monolayers sensitized with polyclonal rabbit anti-oxE antibody (AB), showed no plaque formation over control oxE layers. No increase in ability to generate cytolytic plaques in antibody-sensitized oxE layers was seen compared with unsensitized oxE layers until after 10 days of incubation in liquid culture. At that time, the percent of cells forming plaques in the AB-sensitized oxE layers was 34.4 +/- 10.7% (average +/- standard error of the mean [SEM]; n = 4) compared with 10.0 +/- 0.7% on the control oxE layers. The peak plaque formation appeared to coincide with the increase in MFI of a large population of the cultured cells.(ABSTRACT TRUNCATED AT 400 WORDS)

Dementia in two histologically confirmed cases of multiple sclerosis: one case with isolated dementia and one case associated with psychiatric symptoms.

During the past 10 years, considerable attention has been devoted to cognitive impairment in multiple sclerosis. Occasionally this impairment may be so severe that multiple sclerosis presents as a dementia associated with only minor neurological signs and symptoms. The cases of two women affected by multiple sclerosis who presented with a pure dementia are reported. In the first patient, a progressive apragmatic behavioural disturbance with reduced short term memory and learning abilities were the main clinical features. Neuropathological examination of the brain disclosed numerous plaques in the periventricular white matter, with severe atrophy of the corpus callosum. Plaques were also seen in the white matter of both hippocampus and in the columns of the fornix. The impairment of short term memory could be linked to these lesions. Behavioural changes were probably related to the bilateral lesions of the long associative bundles that disconnected the frontal lobes from other parts of the cerebral hemispheres. In the second patient, visual hallucinations were associated with cognitive dysfunction. MRI showed large plaques in the white matter of both left frontal and temporal lobes. Smaller plaques were also present in the periventricular white matter of the occipital lobes, the nature of which were confirmed by a stereotactic biopsy.

Pure progressive aphemia.

Aphemia, also called anarthria or severe apraxia of speech, is a rare disorder of speech production usually resulting from vascular lesions affecting the inferior premotor cortex of the left hemisphere. A patient presenting with aphemia as the sole manifestation of primary progressive aphasia (PPA) is reported.