Pressurized bag pump and syringe pump arterial flushing systems: an unrecognized hazard in neonates?

OBJECTIVE: Hand-held flushing of radial arterial lines at 0.5 ml/s in neonates can result in retrograde embolization of flush solution into the central arterial circulation. We studied flush flow velocities during intermittent arterial line purging using a flow regulating device with an infusion bag pump and a syringe pump system. MEASUREMENTS AND INTERVENTIONS: In this in vitro experiment we simulated flushing of a 24- and a 22-G cannula against a mean arterial pressure of 45 mmHg. Fluid flow velocities were gravimetrically measured during flushing from an infusion bag system pressurized to 100, 200, and 300 mmHg and from a syringe pump flush system after initialization of boluses of 0.5, 1.0, 1.5, 2.0, and 2.5 ml. The flow regulating device was opened for 1, 2, and 5 s. RESULTS: Both flush systems tested allowed delivery of flush flow velocities exceeding 0.5 ml/s (e.g., 22-G cannula; bag system, pressure 300 mmHg up to 0.64+/-0.08 ml/s; syringe pump, 2 ml bolus up to 0.74+/-0.05 ml/s). In syringe pump systems the main determinant of flow velocity was bolus size, in bag pump systems flushing time and bag pressure. CONCLUSIONS: Based on data about critical flow velocities through an radial arterial cannula in neonates, both tested flushing systems carry the risk of exceeding the critical value of 0.5 ml/s. They are likely to cause retrograde embolization of flushing solution into the central arterial circulation with the associated risk of clot and air embolization. In vivo studies should identify margins of safety to minimize the risk of retrograde flushing into the central arterial circulation.     

Gentamicin Increases the Efficacy of Vancomycin against Penicillin-Resistant Pneumococci in the Rabbit Meningitis Model

In experimental meningitis a single dose of gentamicin (10 mg/kg of body weight) led to gentamicin levels in around cerebrospinal fluid (CSF) of 4 mg/liter for 4 h, decreasing slowly to 2 mg/liter 4 h later. The CSF penetration of gentamicin ranged around 27%, calculated by comparison of areas under the curve (AUC in serum/AUC in CSF). Gentamicin monotherapy (-1.24 log(10) CFU/ml) was inferior to vancomycin monotherapy (-2.54 log(10) CFU/ml) over 8 h against penicillin-resistant pneumococci. However, the combination of vancomycin with gentamicin was significantly superior (-4.48 log(10) CFU/ml) compared to either monotherapy alone. The synergistic activity of vancomycin combined with gentamicin was also demonstrated in vitro in time-kill assays.     

Patient education program to teach energy conservation behaviors to patients with rheumatoid arthritis: a pilot study

We report a prospective, randomized pilot study comparing a new workbook-based program, designed to teach patients with rheumatoid arthritis (RA) energy conservation behaviors, with standard occupational therapy (OT). Sixteen patients took part in the new program and nine received the standard therapy. Data on the number of tender or swollen joints, grip strength, walk time, activities of daily living, psychologic adjustment to illness, and daily activity log, were measured before and three months after intervention. Eleven percent of those who received standard therapy and 50% of those who received the workbook increased their amount of physically active time (p = .10). Twenty-two percent of the control group and 50% of those in the workbook group achieved a better balance of rest and physical activity (p = .07). We conclude that the adoption of energy conservation behaviors is different in the two groups. This initial study suggests that interrupting physical activity with rest periods may result in increased physical activity in patients with RA.     

瞬时性受体电位通道香草酸受体5、6与骨代谢的关系

目的:探讨瞬时性受体电位通道香草酸受体5、6与骨代谢的关系。资料来源:应用计算机检索PubMed数据库1999-01/2006-07相关瞬时性受体电位通道方面的文献,检索词“TRPV”,限定文献语言种类为English。资料选择:对资料进行初审,选取包括瞬时性受体电位通道香草酸受体5、6的文献,开始查找全文。纳入标准:对两者及瞬时性受体电位通道家族进行研究的文章。排除标准:研究内容局限于瞬时性受体电位通道香草酸受体1～4的文章。资料提炼:共检索到106篇关于瞬时性受体电位通道香草酸受体的文献,最终纳入30篇符合标准的文献。资料综合:瞬时性受体电位通道香草酸受体5、6是瞬时性受体电位通道超家族中的成员,是专门的上皮样钙离子通道。目前研究已经证明它们在肠道和肾脏等组织中有表达,并对跨细胞钙离子转运起着关键性调控作用。但在骨组织中表达情况相关报道较少,在骨代谢机制上的研究更少,本文针对目前两者与骨代谢的关系进行综述。结论:深入研究瞬时性受体电位通道香草酸受体5、6钙离子通道在骨代谢中的作用,对于那些与骨代谢相关疾病的治疗将能从分子水平上找到解决的方法。     

Blood transfusion costs: a multicenter study

The cost of delivering a unit of blood (whole blood or red cells) to a hospitalized patient was examined in 19 United States teaching hospitals. The average hospital acquisition cost was calculated by using the prices charged by regional blood centers for blood products. To this cost was added an estimate of costs incurred by hospitals for handling, testing, and administering blood. Across study sites, the average hospital cost per unit transfused was $155 and the average charge to the patient was $219. Acquisition cost, the price that hospitals pay for blood, was 37 percent of the total cost to the hospital; the other 63 percent of the hospital cost included costs for blood bank handling (13%), laboratory tests (43%), and blood administration (7%). Significant variations in blood transfusion cost were found within our sample. Most of the variability can be attributed to geographic location of the blood supply source, type of red cell product transfused, prices charged by blood transfusion services, and the frequency of laboratory tests. The results of this transfusion cost study may be helpful in determining the costs of health care delivery, especially when blood transfusions are indicated.     

Aerosol immunization with NYVAC and MVA vectored vaccines is safe, simple, and immunogenic

Each year, approximately five million people die worldwide from putatively vaccine-preventable mucosally transmitted diseases. With respect to mass vaccination campaigns, one strategy to cope with this formidable challenge is aerosol vaccine delivery, which offers potential safety, logistical, and cost-saving advantages over traditional vaccination routes. Additionally, aerosol vaccination may elicit pivotal mucosal immune responses that could contain or eliminate mucosally transmitted pathogens in a preventative or therapeutic vaccine context. In this current preclinical non-human primate investigation, we demonstrate the feasibility of aerosol vaccination with the recombinant poxvirus-based vaccine vectors NYVAC and MVA. Real-time in vivo scintigraphy experiments with radiolabeled, aerosol-administered NYVAC-C (Clade C, HIV-1 vaccine) and MVA-HPV vaccines revealed consistent mucosal delivery to the respiratory tract. Furthermore, aerosol delivery of the vaccines was safe, inducing no vaccine-associated pathology, in particular in the brain and lungs, and was immunogenic. Administration of a DNA-C/NYVAC-C prime/boost regime resulted in both systemic and anal-genital HIV-specific immune responses that were still detectable 5 months after immunization. Thus, aerosol vaccination with NYVAC and MVA vectored vaccines constitutes a tool for large-scale vaccine efforts against mucosally transmitted pathogens.     

Effect of nitrates on left ventricular size and function during exercise: Comparison of sublingual nitroglycerin and nitroglycerin paste

To compare the effects of sublingual nitroglycerin and nitroglycerin paste on left ventricular size and performance during supine bicycle exercise, equilibrium radionuclide angiography was performed in 36 persons classified into two groups of normal subjects and two groups of patients with angiographically proved coronary heart disease. Each group underwent a control exercise study, and then one group of normal subjects and one group of patients were restudied after the administration of 0.6 mg of nitroglycerin or 2 inches (5 cm) of nitroglycerin paste (but not both). Data were collected at rest and at peak exercise.In normal subjects exercise resulted in increased ejection fraction, decreased end-systolic volume and little change in end-diastolic volume. After either drug, volumes at rest markedly decreased, and during exercise, ejection fraction increased to levels comparable with pre-drug levels. After nitroglycerin paste the reduction in volume seen at rest persisted during exercise, but after sublingual nitroglycerin end-diastolic volume increased during exercise (88 ± 43 to 113 ± 30 ml [mean ± standard deviation]; p < 0.01). Peak exercise end-diastolic volume after nitroglycerin was still lower than that before nitroglycerin (113 ± 30 versus 120 ± 28 ml, p < 0.05).In patients with coronary disease, ejection fraction did not change during exercise, but both end-diastolic and end-systolic volumes increased. After either drug ejection fraction at rest was unchanged, although ventricular volumes were markedly lower (p < 0.05). Ejection fraction increased with exercise in both groups with coronary disease after either drug. After sublingual nitroglycerin, volumes increased during exercise although the peak exercise end-diastolic volume was still lower than the control value (113 ± 31 versus 145 ± 34 ml; p < 0.01). After paste administration, end-diastolic volume did not change during exercise, and end-systolic volume decreased (41 ± 20 to 36 ± 22 ml; p < 0.05).Thus, sublingual nitroglycerin and nitroglycerin paste improved left ventricular function during exercise. The effect of paste on end-diastolic volume appeared sustained, whereas that of sublingual nitroglycerin was transient, confirming the hypothesis that reduction in end-diastolic volume and, by implication, left ventricular wall tension, is a major mechanism of nitrate action.     

Circulating malignant cells in non-Hodgkin's lymphoma: correlation with binding by peanut agglutinin

A significant number of patients with non-Hodgkin's lymphoma have peripheral blood involvement during the course of their disease. Because the expression of receptor for the lectin peanut agglutinin PNA by normal lymphocytes is associated with noncirculating (stationary phase) cells, we studied the relationship between PNA binding by lymphoma cells and the presence of clonal B cells in the blood of 38 patients with B-cell lymphoma. The binding of PNA by cells in tissues was determined by the immunoperoxidase method and by two-color flow cytometry. Circulating lymphoma cells (clonal B cells) were identified by a sensitive flow-cytometric technique (kappa-lambda analysis) and were also studied for PNA binding in some cases. In all, 16 of 38 (42%) of lymphomas were PNA+, including a spectrum of histologic types. Circulating lymphoma cells were demonstrated in 17 of 22 PNA-lymphomas, whereas only 3 of 16 of PNA+ lymphomas had such circulating cells. Thus, there is a significant association between PNA binding and peripheral blood involvement by lymphoma (P less than .005 by chi- square analysis). In 12 cases, the circulating and tissue lymphoma cells had similar expression of PNA receptor (2 PNA+ and 10 PNA- cases), indicating that modulation of the PNA binding sites did not occur. In three patients who presented with lymphosarcoma cell leukemia, the circulating malignant cells were PNA-. These findings suggest that for both normal and malignant lymphocytes the absence of binding sites for PNA is associated with the capacity of these cells to circulate freely.     

Partial purification and characterization of a growth factor for macrophage progenitor cells with high proliferative potential in mouse bone marrow

A population of macrophage progenitor cells, with high proliferative potential, has recently been demonstrated in postfluorouracil-treated and normal mouse bone marrow (BM) in vitro, when the newly discovered growth factor (synergistic activity, SA) is combined with a macrophage colony-stimulating factor (CSF) as a proliferative stimulus. SA, shown to be present in human spleen and placental conditioned media (HSCM and HPCM, respectively) have been studied and found to be unstable to trypsin digestion and to heating at 50 degrees C or above; stable between pH 4 and 9; nonadherent to Con-A-Sepharose; and to have an isoelectric point between pH 5 and 5.8 and a molecular weight of between 14,000 and 21,000 as indicated by gel filtration chromatography. SAs from both HSCM and HPCM have been purified 89- and 122-fold, respectively, by precipitation of extraneous proteins at pH 5 followed by chromatographing twice on Sephacryl S200. Neither of these partially purified SAs contain any CSF for mouse BM. These results indicate that the SAs from HSCM and HPCM may be closely related and that they are structurally different from CSFs derived from various murine sources that have been shown to be stable to proteolytic enzymes and heat.     

A cardiac myocyte vascular endothelial growth factor paracrine pathway is required to maintain cardiac function

The role of the cardiac myocyte as a mediator of paracrine signaling in the heart has remained unclear. To address this issue, we generated mice with cardiac myocyte-specific deletion of the vascular endothelial growth factor gene, thereby producing a cardiomyocyte-specific knockout of a secreted factor. The hearts of these mice had fewer coronary microvessels, thinned ventricular walls, depressed basal contractile function, induction of hypoxia-responsive genes involved in energy metabolism, and an abnormal response to beta-adrenergic stimulation. These findings establish the critical importance of cardiac myocyte-derived vascular endothelial growth factor in cardiac morphogenesis and determination of heart function. Further, they establish an adult murine model of hypovascular nonnecrotic cardiac contractile dysfunction.