In vivo comparison of two through-plane MR velocity mapping methods: Fast fourier encoding and phase mapping

Magnetic resonance imaging maps of velocity were acquired with a 1.5-T system in 10 subjects in a plane perpendicular to the main pulmonary artery. Velocity images were successively acquired with a method developed from Fourier-encoding velocity imaging (FEVI) principles with eight gradient steps and one excitation, and with two-point phase-subtraction mapping. Reconstruction in FEVI was implemented by zero-filling interpolation around the eight gradient steps and then around the four central steps. The methods were compared by using estimates of noise in velocity measurements based on the difference between the experimental map and a smooth fitted map. For the same acquisition time, FEVI with four encoding steps was more precise in velocity measurements than phase mapping. Precision was further increased by the use of eight encoding steps, but acquisition time was doubled.     

Genetic restriction of murine hepatitis virus type 3 expression in liver and brain: comparative study in BALB/c and C3H mice by immunochemistry and hybridization in situ

Summary To study the host-dependent genetic variations in murine hepatitis virus type 3 (MHV 3) induced diseases, we localized the sites of MHV 3 (Mill Hill strain) expression within liver and brain by immunohistochemistry or hybridization in situ. Two strains of mice were studied: BALB/c mice, which develop an acute and lethal hepatitis and C3H mice which develop a chronic brain infection. In BALB/c mice, viral RNA and antigens appeared during the first 24 h post infection (p.i.) in liver, whereas viral RNA was barely detectable in brain, up until death at day 3 p.i. In C3H mice, viral RNA and antigens were detected simultaneously in liver and brain only at day 2 p.i. In brain, the virus was detected in meningeal and ependymal cells and in perivascular cortical areas (days 5 and 7 p.i.). After day 49, the virus was no longer detected in brain parenchyma, but persisted in meningeal cells. Two host-dependent genetic differences in viral processing were observed in the liver: (1) the virus was first detected in Kupffer cells in BALB/c mice and mostly in hepatocytes in C3H mice; (2) in BALB/c mice, the 180 kDa S viral glycoprotein appeared more frequently cleaved in 90 kDa form than in C3H mice.     

IL-5 is essential for vaccine-induced protection and for resolution of primary infection in murine filariasis

The pathways conferring immunity to human filariases are not well known, in part because human-pathogenic filariae do not complete a full life cycle in laboratory mice. We have used the only fully permissive infection of mice with filariae, i.e., infection of BALB/c mice with the rodent filarial nematode Litomosoides sigmodontis. Our previous results showed that worm development is inversely correlated with Th2 cytokine production and eosinophilia. The scope of the present study was to directly elucidate the role of interleukin-5 (IL-5) and eosinophils in controlling the development of L. sigmodontis after vaccination and in primary infection. BALB/c mice immunized with irradiated third-stage larvae (L3) were confirmed to have elevated IL-5 levels as well as high subcutaneous eosinophilia and to attack and reduce incoming larvae within the first 2 days, resulting in 70% reduction of worm load. Treatment of vaccinated mice with anti-IL-5 antibody (TRFK-5) suppressed both blood and tissue eosinophilia and completely abolished protection. This demonstrates, for the first time in a fully permissive filarial infection, that IL-5 is essential for protection induced by irradiated L3 larvae. In contrast, in primary-infected mice, anti-IL-5 treatment did not modify filarial infection within the 1st month, most likely because during primary infection IL-5-dependent mechanisms such as subcutaneous eosinophilia are induced too late to disturb worm establishment. However, there is a role for IL-5 late in primary infection where neutrophil-dependent worm encapsulation is also under the control of IL-5. Received: 30 March 2000     

Phosphatidylserine externalization in human sperm induced by calcium ionophore A23187: relationship with apoptosis, membrane scrambling and the acrosome reaction

BACKGROUND: Translocation of phosphatidylserine (PS) from the inner to the outer leaflet of the plasma membrane is a modification of the lipid architecture occurring in sperm. This is one of the earliest signs of apoptosis that can be monitored by the calcium-dependent binding of annexin V. METHODS AND RESULTS: Flow cytometric analysis of annexin V binding was performed. Calcium ionophore A23187 led to a significant increase in the proportion of living sperm with PS exposure: 7.3 3.2% of cells in the untreated ejaculate versus 47.5 5.6% of cells after 1 h of incubation with A23187. Conversely, diminution of mitochondrial membrane potential [DiOC6(3)/propidium iodide (PI) assay], caspase activation [fluorescein isothiocyanate (FITC)-Val-Ala-Asp-fluoromethylketone (VAD-FMK)/PI assay], increased plasma membrane permeability (Yo-Pro-1/PI assay) and increased DNA fragmentation [TdT (terminal deoxynucleotidyl transferase)-mediated dUDP nick-end labelling assay], which are among the main signs of apoptosis, were not observed in sperm, even after 4 h of incubation with A23187. However, A23187 significantly increased the proportion of sperm with plasma membrane scrambling and with a reacted acrosome, as detected with the merocyanine 540 probe (M540) and the monoclonal anti-human CD46-PE antibody respectively. CONCLUSIONS: Our results suggest that PS exposure in human sperm, as induced by A23187, is mainly related to the acrosome reaction rather than to apoptosis.     

Contribution of cellular HIV-1 DNA quantification to the efficacy analysis of antiretroviral therapy: a randomized comparison of 2 regimens, including 3 drugs from 2 or 3 classes (TRIANON, ANRS 081)

Cellular HIV-1 DNA level was sequentially measured by quantitative polymerase chain reaction in 141 patients not previously treated with highly active antiretroviral therapy (HAART), who were enrolled in a 72-week randomized trial (ANRS 081 "Trianon") comparing 2 regimens, including 3 drugs from 2 classes (indinavir + stavudine + lamivudine, group 1) or 3 classes (indinavir + stavudine + nevirapine, group 2). The median decrease from baseline to week 72 in cellular HIV-1 DNA level was not significantly different between the 2 groups (0.54 and 0.45 log10 copies/10 peripheral blood mononuclear cells [PBMCs] in groups 1 and 2, respectively), whereas a higher proportion of patients maintained a plasma HIV-1 RNA level less than 20 copies/mL at week 72 in group 1 than in group 2 (79% and 52%; P = 0.0009). Furthermore, the difference in cellular HIV-1 DNA decrease from baseline to week 72 between patients who achieved a plasma HIV-1 RNA level less than 20 copies/mL at week 72 and those who did not was not statistically significant (0.54 and 0.45 log10 copies/10 PBMCs, respectively; P = 0.14). The decay in cellular HIV-1 DNA from baseline to week 72 was higher in antiretroviral-naive patients than in pretreated patients (0.55 and 0.23 log10 copies/10 PBMCs, respectively; P = 0.0008). The cellular HIV-1 DNA level change under therapy was best fitted to a 2-phase decay model with a junction point at week 16, from which its half-life was estimated at 18 weeks during the initial phase and at 104 weeks thereafter. In conclusion, the changes under therapy in cellular HIV-1 DNA level, which were mostly coincident to those of plasma HIV-1 RNA, did not add significant information to the comparison of the viral efficacy of the 2 studied regimens.     

Comparison of the real-time PCR method and the Gen-Probe amplified Mycobacterium tuberculosis direct test for detection of Mycobacterium tuberculosis in pulmonary and nonpulmonary specimens

Real-time PCR was compared to Amplified Mycobacterium tuberculosis Direct Test (AMTDII) for 100 clinical specimens. The overall sensitivities of the real-time PCR method and AMTDII were similar for respiratory and nonrespiratory specimens. However, real-time PCR seemed to be less susceptible to amplification inhibitors than AMTDII.     

Diffuse neuroendocrine differentiation in a morphologically composite mammary infiltrating ductal carcinoma: a case report and review of the literature

Neuroendocrine differentiation has been reported in both in situ and infiltrating breast cancers. The prognostic significance of neuroendocrine differentiation in mammary carcinoma is unclear. We report a case of infiltrating ductal carcinoma in which there was a morphologically conventional-appearing infiltrating ductal component admixed with nests of cells that resembled a carcinoid tumor and initially mimicked the appearance of intraductal carcinoma. Immunohistochemical stains for synaptophysin and chromogranin demonstrated diffuse, strong positivity uniformly throughout the tumor, even in the more conventional-appearing areas. Electron microscopic examination of tissue retrieved from paraffin blocks was attempted unsuccessfully. We concluded that this was an infiltrating ductal carcinoma with morphologic and immunohistochemical evidence of neuroendocrine differentiation. The case is discussed with a review of the literature and a discussion of nomenclature for tumors of the breast showing variable degrees of neuroendocrine differentiation.     

Low serum cholesterol in violent but not in non-violent suicide attempters

Many previous studies have suggested that low or lowered serum cholesterol levels may increase the risk of mortality not due to somatic disease: principally, suicide and violent death. Because violent death is rare, some studies have investigated afterwards the relation between cholesterol levels and either suicide attempts in psychiatric populations or violence in criminally violent populations. However, none of these studies have compared cholesterol levels in violent and non-violent suicide attempters. The blood of 25 consecutive drug-free patients following a violent suicide attempt and of 27 patients following a non-violent suicide attempt by drug overdose was drawn in the 24 h following admission. Patients with a diagnosis of alcohol abuse and with cholesterol-lowering therapy were excluded. Age, sex, body mass index, psychiatric diagnosis and the physical conditions of the suicide attempt were investigated. Thirty-two healthy subjects were used as a control group. There were no differences between the groups in age, frequency of psychiatric diagnoses or body mass index. There was more women in the group of non-violent suicide attempters than in that of violent suicide attempters (P<0.001). In analyses controlling for sex and age, the serum cholesterol concentration was 30% lower (F(2,82)=15.8; P<0.0001) in the group of violent suicide attempters (147+/-54 mg/dl) than in the group of non-violent suicide attempters (209+/-38 mg/dl) or control subjects (213+/-46 mg/dl). Our results showed that low serum cholesterol level is associated with the violence of the suicide attempt and not with the suicide attempt itself. Further investigations are necessary to determine the usefulness of this easily accessible parameter as a potential risk indicator for violent acts such as violent suicidal behavior in susceptible individuals.     

Abnormal white‐matter rich‐club organization in obsessive–compulsive disorder

Rich‐club organization is key to efficient global neuronal signaling and integration of information. Alterations interfere with higher‐order cognitive processes, and are common to several psychiatric and neurological conditions. A few studies examining the structural connectome in obsessive–compulsive disorder (OCD) suggest lower efficiency of information transfer across the brain. However, it remains unclear whether this is due to alterations in rich‐club organization. In the current study, the structural connectome of 28 unmedicated OCD patients, 8 of their unaffected siblings and 28 healthy controls was reconstructed by means of diffusion‐weighted imaging and probabilistic tractography. Topological and weighted measures of rich‐club organization and connectivity were computed, alongside global and nodal measures of network integration and segregation. The relationship between clinical scores and network properties was explored. Compared to healthy controls, OCD patients displayed significantly lower topological and weighted rich‐club organization, allocating a smaller fraction of all connection weights to the rich‐club core. Global clustering coefficient, local efficiency, and clustering of nonrich club nodes were significantly higher in OCD patients. Significant three‐group differences emerged, with siblings displaying highest and lowest values in different measures. No significant correlation with any clinical score was found. Our results suggest weaker structural connectivity between rich‐club nodes in OCD patients, possibly resulting in lower network integration in favor of higher network segregation. We highlight the need of looking at network‐based alterations in brain organization and function when investigating the neurobiological basis of this disorder, and stimulate further research into potential familial protective factors against the development of OCD.     

High-affinity autoreactive plasma cells disseminate through multiple organs in patients with immune thrombocytopenic purpura

The major therapeutic goal for immune thrombocytopenic purpura (ITP) is to restore normal platelet counts using drugs to promote platelet production or by interfering with mechanisms responsible for platelet destruction. Eighty percent of patients with ITP possess anti–integrin αIIbβ3 IgG autoantibodies that cause platelet opsonization and phagocytosis. The spleen is considered the primary site of autoantibody production by autoreactive B cells and platelet destruction. The immediate failure in approximately 50% of patients to recover a normal platelet count after anti-CD20 rituximab-mediated B cell depletion and splenectomy suggests that autoreactive, rituximab-resistant, IgG-secreting B cells (IgG-SCs) reside in other anatomical compartments. We analyzed more than 3,300 single IgG-SCs from spleen, bone marrow, and/or blood of 27 patients with ITP, revealing high interindividual variability in affinity for αIIbβ3, with variations over 3 logs. IgG-SC dissemination and range of affinities were, however, similar for each patient. Longitudinal analysis of autoreactive IgG-SCs upon treatment with the anti-CD38 mAb daratumumab demonstrated variable outcomes, from complete remission to failure with persistence of high-affinity anti–αIIbβ3 IgG-SCs in the bone marrow. This study demonstrates the existence and dissemination of high-affinity autoreactive plasma cells in multiple anatomical compartments of patients with ITP that may cause the failure of current therapies.