Diabetic neuropathy increases stimulation threshold during popliteal sciatic nerve block.

BACKGROUND: Peripheral nerve stimulation is commonly used for nerve localization in regional anaesthesia, but recommended stimulation currents of 0.3-0.5 mA do not reliably produce motor activity in the absence of intraneural needle placement. As this may be particularly true in patients with diabetic neuropathy, we examined the stimulation threshold in patients with and without diabetes. METHODS: Preoperative evaluation included a neurological exam and electroneurography. During ultrasound-guided popliteal sciatic nerve block, we measured the current required to produce motor activity for the tibial and common peroneal nerve in diabetic and non-diabetic patients. Proximity to the nerve was evaluated post-hoc using ultrasound imaging. RESULTS: Average stimulation currents did not differ between diabetic (n=55) and non-diabetic patients (n=52). Although the planned number of patients was not reached, the power goal for the mean stimulation current was met. Subjects with diminished pressure perception showed increased thresholds for the common peroneal nerve (median 1.30 vs. 0.57 mA in subjects with normal perception, P=0.042), as did subjects with decreased pain sensation (1.60 vs. 0.50 mA in subjects with normal sensation, P=0.038). Slowed ulnar nerve conduction velocity predicted elevated mean stimulation current (r=-0.35, P=0.002). Finally, 15 diabetic patients required more than 0.5 mA to evoke a motor response, despite intraneural needle placement (n=4), or required currents ≥2 mA despite needle-nerve contact, vs three such patients (1 intraneural, 2 with ≥2 mA) among non-diabetic patients (P=0.003). CONCLUSIONS: These findings suggest that stimulation thresholds of 0.3-0.5 mA may not reliably determine close needle-nerve contact during popliteal sciatic nerve block, particularly in patients with diabetic neuropathy. CLINICAL TRIAL REGISTRATION: NCT01488474.

Ventilatory thresholds determined from HRV: comparison of 2 methods in obese adolescents.

The development of personalised training programmes is crucial in the management of obesity. We evaluated the ability of 2 heart rate variability analyses to determine ventilatory thresholds (VT) in obese adolescents. 20 adolescents (mean age 14.3±1.6 years and body mass index z-score 4.2±0.1) performed an incremental test to exhaustion before and after a 9-month multidisciplinary management programme. The first (VT1) and second (VT2) ventilatory thresholds were identified by the reference method (gas exchanges). We recorded RR intervals to estimate VT1 and VT2 from heart rate variability using time-domain analysis and time-varying spectral-domain analysis. The coefficient correlations between thresholds were higher with spectral-domain analysis compared to time-domain analysis: Heart rate at VT1: r=0.91 vs. =0.66 and VT2: r=0.91 vs. =0.66; power at VT1: r=0.91 vs. =0.74 and VT2: r=0.93 vs. =0.78; spectral-domain vs. time-domain analysis respectively). No systematic bias in heart rate at VT1 and VT2 with standard deviations <6 bpm were found, confirming that spectral-domain analysis could replace the reference method for the detection of ventilatory thresholds. Furthermore, this technique is sensitive to rehabilitation and re-training, which underlines its utility in clinical practice. This inexpensive and non-invasive tool is promising for prescribing physical activity programs in obese adolescents.

Alzheimer CSF biomarkers in routine clinical setting.

OBJECTIVES: Our work was aimed to evaluate Alzheimer's disease diagnosis improvement using cerebrospinal fluid biomarkers (CSF) in neurological daily practice. MATERIALS AND METHODS: For this purpose, 150 patients clinically and neurochemically classified as having AD or cognitive impairment with or without other dementia type were included in the study. The following CSF peptides were studied, blindly to the clinical diagnosis: beta-amyloid(1-42) peptide (Aß(1-42)), Tau (T-tau), threonine-181 hyperphosphorylated tau protein (P-tau(181)), and beta-amyloid(1-40) peptide (Aß(1-40)). From these measurements, Innotest® Amyloid Tau Index (IATI) was calculated for each patient. RESULTS: This assessment allowed to separate 83 biochemical profiles of AD and 67 non-Alzheimer's disease (non-AD), both AD and non-AD categories match with clinical data amounting to 73% and 90%, respectively. Among mild cognitive impairment (MCI) patients, CSF biomarkers led to discriminate those who are likely to be AD. We devoted a special section to Aß(1-40) which is not a routine parameter but can help to confirm a pathological amyloid process as Aß(1-42)/Aß(1-40) ratio underlining the real decline of the Aß(1-42). CONCLUSIONS: The interest of biomarkers and their ability to solve awkward cases were carefully noticed all the more when a discrepancy between clinical and CSF biological data was involved. The final proposed algorithm allowed to identify pathogenic forms of AD according to the prevailing role of hyperphosphorylated tau or amyloid beta peptide.

Chemokine IP-10: an adjunct marker for latent tuberculosis infection in children.

SETTING: Recent reports indicate a role of chemokine inducible protein 10 (IP-10) in Mycobacterium tuberculosis infection substantiated by the detection of elevated levels in plasma and at infection foci in individuals infected with M. tuberculosis. OBJECTIVE: To evaluate IP-10 as a potential marker for the diagnosis of M. tuberculosis infection in children living in a region of low tuberculosis (TB) prevalence. DESIGN: IP-10 levels were obtained after whole blood stimulation with M. tuberculosis-specific antigens in 127 children. IP-10 results were evaluated upon gradations of exposure risk to M. tuberculosis and correlation with tuberculin skin test and an interferon-gamma release assay (IGRA). RESULTS: IP-10 reactivity correlated well to risk of exposure to M. tuberculosis in children. There was a strong correlation between IP-10 and IGRA results. IP-10 responses, unlike interferon-gamma (IFN-gamma), were not age-dependent and detected more positive results in children aged <5 years. In the children with active disease, the IGRA was more sensitive than IP-10 at detecting M. tuberculosis infection. CONCLUSION: Our findings suggest that IP-10 in combination with IFN-gamma may enhance the diagnostic performance of IGRAs in detecting M. tuberculosis infection, especially in young children.

Non-invasive imaging correlates with histological and molecular characteristics of an osteosarcoma model: application for early detection and follow-up of MDR phenotype.

BACKGROUND: In an orthotopic rat osteosarcoma model, histological and molecular findings were compared with the results of non-invasive imaging methods to assess disease progression at the primary site, the pattern of metastatic dissemination and the chemoresistance phenotype. MATERIALS AND METHODS: Primary tumor engraftment, vascularization, growth and metastatic spread were evaluated using 18FDG tomoscintigraphy. Bone neoformation in the primary tumor and metastasis was determined using 18FNa confirmed by classical histological studies. Chemoresistance phenotype was assessed by analysis of MDR1 and MRP1 genes expression compared to 99mTc MIBI imaging. RESULTS: 99mTc MIBI imaging correlated with the overexpression of the MDR1 and MRP1 genes. 18FDG, 18FNa and 99mTc tomoscintigraphies revealed that the pattern of vascularization, bone neoformation and hematogeneous metastatic dissemination in our animal model mimics its human counterpart. CONCLUSION: Multimodality, non-invasive imaging is a valid surrogate marker of histological and molecular characteristics in an orthotopic osteosarcoma model in immunocompetent rats; it allows extensive in vivo follow-up of osteosarcoma, including longitudinal analysis of chemoresistance.

[A rare familial form of idiopathic pulmonary fibrosis with Poly(A)-specific ribonuclease (PARN) mutation]. / Mutation poly(A)-specific ribonuclease (PARN) et fibrose pulmonaire idiopathique familiale : à propos d'un cas au centre hospitalier universitaire de Bordeaux.

New techniques of DNA sequences allow to discover genetics mutations involved in familial pulmonary fibrosis. Among them, the PARN (Poly[A]-specific ribonuclease) mutation. Herein, we report the case of one patient who has pulmonary fibrosis with PARN mutation and the experience of our patient care.

Transfomration of arachidonic acid into 12-hydroxy-5,8,10,14-eicosatetraenoic acid by mouse peritoneal macrophages.

Mouse peritoneal macrophages were incubated at 37 degrees C for 30 min with arachidonic acid (all-cis-5,8,11,14-eicosatetraenoic acid). Oxygenation of arachidonic acid in mouse peritoneal macrophages occurs by two major pathways: fatty acid cyclooxygenase and lipoxygenase. The major metabolite of the latter is 12-hydroxy-5,8,10,14-eicosatetraenoic acid which was identified by gas liquid chromatography on high resolution glass capillary column and mass spectrometry.

Inhibition of lipoxygenase activity and HL60 leukemic cell proliferation by ursolic acid isolated from heather flowers (Calluna vulgaris).

A compound was isolated and purified from heather flowers (Calluna vulgaris) based on its ability to inhibit lipoxygenase activity. This molecule was characterized as ursolic acid by GC-MS. Ursolic acid was found to be an inhibitor of both potato tuber 5-lipoxygenase and soybean 15-lipoxygenase with IC50 values of 0.3 mM. Ursolic acid also inhibits lipoxygenase activity in mouse peritoneal macrophages at 1 microM and HL60 leukemic cells growth (IC50 = 0.85 microM) as well as their DNA synthesis (IC50 = 1 microM). The possible role of lipoxygenase inhibition in the proliferation of leukemic cells is discussed.

Enzymatic synthesis of structural analogs of PAF-acether by phospholipase D-catalysed transphosphatidylation.

PAF-acether can be transformed into analogs by the phospholipase D enzyme activity of Streptomyces sp. In this reaction choline is replaced by primary cyclic alcohols (acceptors). The reaction products, cyclic phospholipid and phosphatidic acid, were separated by silicic acid chromatography. This procedure enabled us to synthetize five analogs of PAF-acether, with a cyclic ring structure. The primary cyclic alcohols used in this work were: 3-(2-hydroxyethyl)-indol, OH-Et-I; 2-(hydroxymethyl)-1,4-benzodioxan, OH-Met-BZD; N-(2-hydroxyethyl)-phthalimide, OH-Et-PHT; 2-(2-thienyl)-ethanol, Th-EtOH; (1-R)-(-)-Nopol, R-NOP.

Linoleic acid peroxidation by Solanum tuberosum lipoxygenase was activated in the presence of human 5-lipoxygenase-activating protein.

The present investigation describes the ability of human 5-lipoxygenase-activating protein (FLAP) to activate a plant 5-lipoxygenase. The presence of an active recombinant human FLAP in the 100000xg membrane fraction of infected Sf9 cells led to a specific increase in 9-hydroperoxyoctadecadienoic acid (9-HPOD) synthesis (+68%) or in 5-hydroperoxyeicosatetraenoic acid (5-HPETE) synthesis (+68%), after action of Solanum tuberosum tuber 5-lipoxygenase (S.t.LOX) on linoleic acid (natural plant lipoxygenase substrate) or on arachidonic acid. On the contrary, the presence of non-transfected membranes obtained from non-infected Sf9 cells led to an inhibition of lipoxygenase activity. MK-886, a potent inhibitor of leukotriene biosynthesis, blocked the FLAP dependent S.t.LOX activation after preincubation with FLAP transfected membranes. In conclusion, this study demonstrates that a recombinant human FLAP can stimulate a lipoxygenase other than mammalian 5-lipoxygenase (S.t.LOX) by using different polyunsaturated fatty acids as substrates.

Hydroperoxyeicosatetraenoic acids. Potent inhibitors of lymphocyte responses.

Arachidonic acid can be transformed into a series of HPETEs by the lipoxygenase enzyme activity of mouse peritoneal macrophages. These resulting HPETEs inhibit some mouse lymphocyte responses. When mice are injected with 15-L-HPETE, their splenocytes show a decreased [3H]thymidine uptake after lectin stimulation.

Effects of full-dose heparin anticoagulation on the development of left ventricular thrombosis in acute transmural myocardial infarction.

The incidence of left ventricular thrombosis after acute transmural myocardial infarction has been evaluated with two-dimensional echocardiography. To assess the preventive action of early anticoagulation with full-dose heparin, 90 patients, admitted within 5.2 +/- 4.6 hours after the onset of symptoms of their first episode of acute myocardial infarction (46 anterior and 44 inferior), were prospectively studied. Patients were randomly assigned either to therapeutic anticoagulation with heparin or to no anticoagulant therapy. Serial two-dimensional echocardiograms were recorded on the day of admission, the next day, days 4 to 7 and days 20 to 50 to detect left ventricular thrombus and to assess global left ventricular performance. On the first echocardiogram (10.3 +/- 8.0 hours after the onset of symptoms) no thrombus was visualized. In 44 patients with inferior myocardial infarction (23 receiving heparin and 21 not receiving heparin) no further left ventricular thrombus developed. In 46 patients with anterior myocardial infarction, 21 additional thrombi developed (45.6%) within 4.3 +/- 3.0 days after the acute event. Thrombus developed in 8 (38%) of 21 patients receiving heparin, compared with 13 (52%) of 25 patients not receiving heparin. This difference in ventricular thrombosis was not statistically significant (chi-square with the Yates correction = 0.76; NS). No difference was found between the subgroups in terms of clinical variables, infarct size, hemodynamic impairment, intensity of the inflammatory process and quantitative two-dimensional echocardiographic and cineangiographic left ventricular function. It is concluded that early anticoagulation with heparin reduced by 27% the incidence of left ventricular thrombus formation in anterior acute transmural myocardial infarction, and this relative risk reduction was not statistically significant when compared with findings in the untreated group.

Contrast echocardiographic visualization of cough-induced right to left shunt through a patent foramen ovale.

In a series of 24 consecutive patients referred to the echocardiography laboratory because of suspected patent foramen ovale, contrast two-dimensional and M-mode echocardiographic studies were performed during normal breathing and during two provocative tests: the Valsalva maneuver and cough. A right to left shunt was visualized in 8 patients during normal breathing, in 11 patients during the Valsalva maneuver and in 17 patients during the cough test. Cardiac catheterization performed in all 24 patients and postmortem examination available in 3 patients confirmed the patency of the foramen ovale in only 15 patients. In these 15 patients, echo contrast appeared in the left heart cavities in early systole and almost simultaneously with complete right heart opacification. In contrast, for the two false positive results during the cough test, ultrasound contrast appeared at any time of the cardiac cycle when the right heart cavities had been partially cleared of contrast material. Right and left atrial pressures were simultaneously measured in four patients, and the normal interatrial pressure gradient was reversed during the Valsalva maneuver and the cough test. Echocardiography during both provocative tests showed that the interatrial septum flattened or became convex toward the left atrium. The cough test appears to be more reliable and easier to perform in critically ill patients than the Valsalva maneuver for the detection of right to left shunting through a patent foramen ovale.

Tumor endothelial cells are targets for selective therapies: in vitro and in vivo models to evaluate antiangiogenic strategies.

Angiogenesis is a complicated process, essential for tumor progression and metastasis. Extensive work has been done to understand the mechanisms of tumor angiogenesis and identify angiogenesis inhibitors. It is now recognised that tumor endothelial cells present different functional and phenotypic characteristics than normal resting endothelial cells. These differences and advances in molecular biology have allowed the development of selective agents targeting tumor endothelial cells as therapeutic approaches for cancer. These new targeted strategies need to be evaluated in relevant models before being transferred from the laboratory bench to the clinic. In vivo tumor models remain a good way to evaluate the effect of these agents on tumor growth and metastasis. Nevertheless, in parallel to the development of tumor angiogenesis inhibitors, in vitro models have been designed to mimic angiogenesis steps and enable the evaluation of these new drugs. In this paper, after reviewing the phenotypic characteristics of tumor endothelial cells that make them easy to target for antiangiogenic therapy, some of the most commonly used in vitro and in vivo models, which enable the evaluation of antiangiogenic agents, are presented and discussed.

Inhibitory effects of AcSDKP on the mixed lymphocyte reaction (MLR). Part I. MLR with mouse spleen cells.

AcSDKP (inhibitor of entry into cycle of pluripotent hemopoietic stem cells) is able to decrease mixed lymphocyte reaction intensity when H-2 incompatible allogeneic spleen cells are used as stimulators. This is a first approach to determining whether AcSDKP has potential therapeutic value for clinical bone marrow transplantation.

Inhibitory effects of AcSDKP on the mixed lymphocyte reaction (MLR). Part II. Human whole blood cells.

AcSDKP is a physiological negative regulator of hematopoietic stem cell proliferation. To investigate the applicability of AcSDKP in the prevention of graft-versus-host disease, this tetrapeptide was tested in mice and showed an inhibitory effect on the mixed lymphocyte reaction (MLR). In this paper we report MLR using human whole blood cells. The maximum inhibitory effect (50%) was obtained at 2.5 ng/ml AcSDKP. All experiments showed a constant dose response. Experiments are now being conducted to elucidate the mechanism of this inhibition.

Correlation of endogenous acetyl-ser-asp-lys-pro plasma levels in mice and the kinetics of pluripotent hemopoietic stem cells entry into the cycle after cytosine arabinoside treatment: fundamental and clinical aspects.

A decrease of endogenous acetyl-ser-asp-lys-pro (AcSDKP) levels in murine plasma was observed after Ara-C treatment. This decrease preceded the entry of pluripotent hemopoietic stem cells (CFU-S) into the cell cycle. This suggests a correlation between CFU-S kinetics and levels of endogenous AcSDKP. The subsequent increase of AcSDKP levels seem to indicate a feedback mechanism which should permit the reestablishment of homeostasis in the stem cells. Therefore, the expulsion of the physiological brake may be the response to a signal (stimulatory factors) to start dividing and the retention of the physiological brake may the mechanism for a return to normal values of cell proliferation.

Serum levels of a negative regulator of cell proliferation (AcSDKP) are increased in certain human haemopathies.

One of the first known effects of the endogenous peptide N-acetyl-Ser-Asp-Lys-Pro (AcSDKP) is to inhibit entry into DNA synthesis of pluripotent haematopoietic stem cells (CFU-S) in mice. A specific anti-AcSDKP polyclonal antibody allows the level of the tetrapeptide by to be determined by enzyme immunoassay with good sensitivity and specificity. We present results demonstrating the presence of AcSDKP in humans: serum levels of 34 healthy controls were found to be between 0.7 and 2.5 pm/ml, regardless of age and sex. High levels were found in 44% of asymptomatic controls but only in 8% of AIDS patients out of a total of 37 patients with HIV. Subsequently, studies of serum levels were performed before treatment in 121 subjects with disorders of the nonlymphoid and the lymphoid lineages. Our results did not demonstrate any decrease in serum levels, however a moderate or marked increase was noted in one-third of the subjects, which was greater in disorders of the non-lymphoid lineages (48% of 72 patients) than the lymphoid lineage (21% of 50 patients). The most significant differences were observed between controls versus patients with myeloproliferative disorders (MPD, 24 patients: p < 0.001), controls versus patients with acute myelogenous leukaemia (AML, 15 patients: p < 0.02), as well as patients with AML versus patients with primary myelodysplastic syndromes (PMDS, 10 patients: p < 0.05). The pathophysiology of these abnormalities is discussed.

Left ventricular compliance in acute myocardial infarction in man.

Left ventricular end-diastolic pressure (P) and volume (V) were measured in 12 patients with acute myocardial infarction. It was assumed that the diastolic P-V relationship was exponential and corresponded to the formula P=be KV. In 7 patients submitted to volume loading, several data points of this relationship were obtained and at zero volume, the mean intercept with the ordinates was 0.037+/-0.015 kPa (SEM) (0.28+/-0.12 mmHg). In the other 5 patients, the P-V curve was plotted through this intercept and the pressure and volume co-ordinates obtained by control. The K coefficient (passive elastic modulus) was greater, and the normalised left ventricular compliance index (dV/VdP) was smaller in the infarct group than in the control group. This suggests decreased left ventricular compliance during the acute phase of myocardial infarction. By comparing left ventricular function curves plotted using either end-diastolic pressure or end-diastolic volume as the stretch index it is possible to evaluate the relative participation of decreased compliance and depressed contractility in global left ventricular function.

Immunologic and virologic responses to HAART in severely immunocompromised HIV-1-infected children.

OBJECTIVE: To determine the long-term immunologic and virologic effects of highly active antiretroviral therapy (HAART) in children with AIDS. DESIGN: A prospective observational study. SETTING: Two pediatric HIV clinics. PARTICIPANTS: Twenty-five protease-inhibitor naive HIV-infected children (aged 2-18 years) with advanced disease (CD4 < or =6%). INTERVENTION: HAART (one protease inhibitor and one or more nucleoside analogs). Diphtheria and tetanus immunization in six patients after 18 months of therapy. MAIN OUTCOME MEASURES: Changes in percentage of CD4 cells and plasma HIV-1 RNA levels; post-treatment assays of lymphoproliferative responses to recall antigens; CD4 cell memory phenotype. RESULTS: Median duration of follow-up was 18.8 months (range, 7.5-28 months). At baseline the CD4 cell percentage was 2% (range, 0-6%), this increased significantly to 16% (range, 3-48%) above baseline at 12 months (P = 0.002). The mean maximum CD4 cell increase was 20.7% (range 4-48%) which corresponds to 657x10(6) cells/l (range, 30-2240x10(6) cells/l) above baseline. By contrast, the median viral load was not significantly lower at 12 months than at baseline (P = 0.34), and only 25% of the patients had sustained undetectable viral load. Of the reconstituted CD4 cells 70% were naive, and none of the subjects had lymphoproliferative responses to tetanus and diphtheria although 40% did develop responses to Candida, an environmental antigen. A single immunization with diphtheria and tetanus toxoid produced lymphoproliferative responses to tetanus in three out of six patients. CONCLUSIONS: HAART was associated with sustained increases in CD4 cell counts, despite a high incidence of 'virologic failure'. CD4 counts and the proportion of naive cells were higher than have been reported in adults, which may be a reflection of greater thymic activity in children. Memory cell clones for antigens encountered in the past which are not prevalent before therapy could not be expanded without additional antigenic exposure.