Pneumococcal polysaccharide vaccine in children with chronic renal disease: a prospective study of antibody response and duration

We studied the antibody response to pneumococcal serotypes 3 and 14 after pneumococcal polysaccharide vaccine was administered to 41 children with renal disease. One month after vaccination, 76% and 61% of patients achieved at least a twofold titer rise to serotypes 3 and 14, respectively; this finding was comparable to historic control values. One year after vaccination, the majority of patients retained protective antibody levels. Achieving a titer > or = 1.0 microgram/ml IgG at 1 month was highly predictive of retaining a protective antibody level > or = 0.15 microgram/ml at 1 year.     

内热式液态合金离子源

本文介绍了一种实用的液态合金离子源结构，我们利用本结构研制成功了Ａｕ－Ｓｉ和Ａｕ－Ｓｉ－Ｂｅ液态合金离子源，测出了它们的发射特性。     

Adeno-associated virus 2-mediated high efficiency gene transfer into immature and mature subsets of hematopoietic progenitor cells in human umbilical cord blood

Recombinant adeno-associated virus 2 (AAV) virions were constructed containing a gene for resistance to neomycin (neoR), under the control of either the herpesvirus thymidine kinase (TK) gene promoter (vTK-Neo), or the human parvovirus B19 p6 promoter (vB19-Neo), as well as those containing an upstream erythroid cell-specific enhancer (HS-2) from the locus control region of the human beta-globin gene cluster (vHS2-TK-Neo; vHS2-B19-Neo). These recombinant virions were used to infect either low density or highly enriched populations of CD34+ cells isolated from human umbilical cord blood. In clonogenic assays initiated with cells infected with the different recombinant AAV-Neo virions, equivalent high frequency transduction of the neoR gene into slow-cycling multipotential, erythroid, and granulocyte/macrophage (GM) progenitor cells, including those with high proliferative potential, was obtained without prestimulation with growth factors, indicating that these immature and mature hematopoietic progenitor cells were susceptible to infection by the recombinant AAV virions. Successful transduction did not require and was not enhanced by prestimulation of these cell populations with cytokines. The functional activity of the transduced neo gene was evident by the development of resistance to the drug G418, a neomycin analogue. Individual high and low proliferative colony-forming unit (CFU)-GM, burst-forming unit-erythroid, and CFU-granulocyte erythroid macrophage megakaryocyte colonies from mock-infected, or the recombinant virus-infected cultures were subjected to polymerase chain reaction analysis using a neo-specific synthetic oligonucleotide primer pair. A 276-bp DNA fragment that hybridized with a neo-specific DNA probe on Southern blots was only detected in those colonies cloned from the recombinant virus-infected cells, indicating stable integration of the transduced neo gene. These studies suggest that parvovirus-based vectors may prove to be a useful alternative to the more commonly used retroviral vectors for high efficiency gene transfer into slow or noncycling primitive hematopoietic progenitor cells, without the need for growth factor stimulation, which could potentially lead to differentiation of these cells before transplantation.     

Placing a bone graft more posteriorly may reduce the risk of pedicle screw breakage: analysis of an unexpected case of pedicle screw breakage

Studies on collagen in heart are important to understand the pathogenesis of myocardial necrosis and to evaluate cardiac function in infarcted heart. The present study has been undertaken to find out the alterations in collagen types in heart as well as serum proteins during myocardial injury in rats. A decreased collagen content was observed on day one which may be due to increased secretion of collagenase and proteases from inflammatory cells or from the myocardium. The changes noticed in the collagen types (I, III and V) indicated the altered elasticity of the heart. Histological studies were observed to correlate well with the biochemical changes in collagen. Evaluation of myocardial collagen could provide new approaches to the treatment of infarct size reduction.     

植被散射实验数据的特性分析

本文根据电波所获取的各种樾 射实测数据，分析了它们对不同极化波的响应特性。     

Role of Epstein-Barr virus in fine-needle aspirates of metastatic neck nodes in the diagnosis of nasopharyngeal carcinoma

The crystal structure of the peptide Boc-Phe-Val-OMe determined by X-ray diffraction methods is reported in this paper. The crystals grown from aqueous methanol are orthorhombic, space group P2(1)2(1)2(1),a = 11.843(2), b = 21.493(4), c = 26.676(4) A3 and V = 6790 A3. Data were collected on a CAD4 diffractometer using MoK alpha radiation (lambda = 0.7107 A) up to Bragg angle theta = 26 degrees. The structure was solved by direct methods and refined by a least-squares procedure to an R value of 6.8% for 3288 observed reflections. There are three crystal-lographically independent peptide molecules in the asymmetric unit. All the three molecules exhibit extended conformation. The sidechain of the Val2 residue shows two different conformations. The conformation of the peptide Boc-Phe-Val-OMe is compared with the conformation of Ac-delta Phe-Val-OH. It is observed that while Boc-Phe-Val-OMe exhibits an extended conformation, Ac-delta Phe-Val-OH shows a folded conformation. The results of this comparison highlight the conformation constraining property of the delta Phe residue. Interestingly, even though Boc-Phe-Val-OMe and Ac-delta Phe-Val-OH are conformationally different, they exhibit similar packing patterns in the solid state.     

Infection and stage conversion during murine pulmonary toxoplasmosis: a study with three different strains of Toxoplasma gondii

OBJECTIVE: To investigate whether intravenously administered liposomal alpha-tocopherol can protect the lung from the injurious action of Escherichia coli lipopolysaccharide (LPS). DESIGN: Prospective, randomized animal study. SETTING: Government research laboratory. SUBJECTS: Twenty adult male Sprague-Dawley rats. INTERVENTIONS: Animals were intravenously pretreated with alpha-tocopherol liposomes (20 mg alpha-tocopherol/kg body weight), plain liposomes, or saline. Twenty-four hours later, pretreated animals were challenged with an intravenous injection of LPS (E. coli 0111:B4, 1 mg/kg body weight), and killed 2 hrs after LPS challenge. MEASUREMENTS AND MAIN RESULTS: Challenge of saline-pretreated animals with LPS resulted in lung injuries as evidenced by an increase in wet lung weight and a reduction in pulmonary angiotensin converting enzyme (25%) and alkaline phosphatase (28%), injury markers of lung endothelial and epithelial type II cells, respectively. Also, LPS administration resulted in an increase in pulmonary myeloperoxidase and protease activities, indicative of a neutrophilic inflammatory response. Pretreatment of animals with liposomal alpha-tocopherol significantly attenuated the LPS-induced edematous lung weight response, and reduced the extent of injuries to the pulmonary endothelial and epithelial cells, demonstrated by a significantly smaller reduction in the corresponding enzyme marker activities. CONCLUSION: These results suggest that augmentation of the pulmonary antioxidant status can ameliorate LPS-induced lung injuries mediated by oxidative stress mechanisms.     

Inhaled nitric oxide is not a myocardial depressant in a porcine model of heart failure

BACKGROUND: Inhaled nitric oxide has been shown to be a potent and selective pulmonary vasodilator. Reports of increases in left ventricular end-diastolic pressure and episodes of pulmonary edema during the clinical use of inhaled nitric oxide in patients with preexisting left ventricular dysfunction have raised concerns that this agent may have myocardial depressant effects. We therefore undertook a study of the effects of inhaled nitric oxide on myocardial contractility in a porcine model of ventricular failure and pulmonary hypertension. METHODS: After inducing heart failure in 10 pigs by rapid ventricular pacing, hemodynamic measurements and pressure-volume diagrams (by the conductance method) were obtained in six animals at baseline and during administration of inhaled nitric oxide at concentrations of 20 and 40 ppm. Myocardial contractile state was assessed by the end-systolic pressure-volume relationship and preload-recruitable stroke work, whereas diastolic function was measured in terms of the end-diastolic pressure-volume relationship and the pressure decay time constant T. RESULTS: Baseline hemodynamics reflected heart failure and pulmonary hypertension, and inhaled nitric oxide induced significant reductions in mean pulmonary artery pressure and pulmonary vascular resistance. Although left ventricular end-diastolic pressure increased during administration of inhaled nitric oxide, no changes were observed in measures of systolic or diastolic function. CONCLUSIONS: Inhaled nitric oxide reduced pulmonary vascular resistance but did not alter myocardial contractility or diastolic function. Increases in left ventricular end-diastolic pressure during inhaled nitric oxide therapy are therefore not due to myocardial depression and may be related to increases in volume delivery to the left side of the heart resulting from reduced pulmonary vascular resistance.     

Enhancement of adenovirus-mediated gene transfer to human bone marrow cells

Adenovirus infection of CD34+ hematopoietic stem/progenitor cells is dependent on the multiplicity of infection (MOI), time of incubation, the volume in which the co-incubation occurs and the presence or absence of growth factors. Studies revealed that a brief co-incubation (1-8 hours), resulted in low levels of transgene expression, suggesting that adenovirus infection of CD34+ cells occurs slowly, and optimal transduction requires a 24 hour exposure to adenovirus. Infection by Ad/beta-gal or Ad/p53 at a MOI of 500:1 provided a high transduction efficiency but inhibited hematopoietic function. However, treatment at a MOI of 50-100 resulted in efficient transduction (10.7-15.7% positive) without detectable toxicity. Secondary proof of adenovirus transgene expression was demonstrated by detection of mRNA for p53 in Ad/p53 infected stem cells. We conclude that a 24 hour exposure to recombinant adenovirus encoding p53 or beta-gal, at a MOI of 50-100 is optimal for in vitro gene transfer to BM cells and has no significant effect on hematopoietic function. Adenovirus-mediated transduction of BM cells can also be modulated by growth factors (IL-3, GM-CSF and G-CSF) with improved gene delivery and maintenance of hematopoietic function. In summary, adenovirus vectors can be used to transiently transduce stem cells, and conditions have been defined to maximize expression and limit inhibitory effects on CD34+ cells. These data support continued investigation of this vector for local cytokine delivery and purging of stem cell products.