首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 0 毫秒
1.
The polysaccharide (PS) capsules of many pathogenic bacteria are poor immunogens in infants and young children as a result of the delayed response to PS antigens during ontogeny. The development of polysaccharide-protein conjugate vaccines for Haemophilus influenzae type b, which have proven to be efficacious in this age group, has led to active development by a number of investigators of conjugate vaccines for other diseases. We describe here the response of several mouse strains to the capsular PS of Neisseria meningitidis group C (MCPS) conjugated to tetanus toxoid (MCPS-TT) and the same response in BALB/c mice as a model of the immune consequences of conjugate vaccine immunization. The use of a conjugate vaccine results in a shift in the isotype elicited in response to the MCPS, from immunoglobulin M (IgM) and IgG3 to primarily IgG1. A response to MCPS-TT is seen even among mouse strains which respond poorly to MCPS itself, emphasizing the importance of a strain survey when choosing a mouse model for a vaccine. The marked increase in IgG1 antibody titer was accompanied by a large increase in bactericidal activity of sera from these animals. Animals primed with the conjugate vaccine demonstrated a booster response after secondary immunization with either the MCPS or the conjugate. The ability to produce a boosted IgG1 anti-MCPS response to the MCPS can be transferred to adoptive recipients by B cells alone from mice primed with MCPS-TT but not mice primed with MCPS alone. These data indicate that in BALB/c mice a single immunization with MCPS-TT is sufficient to induce a shift to IgG1 and generate a memory B-cell population that does not require T cells for boosting.  相似文献   

2.
3.
The ability of the adjuvant MF59 to enhance the immunogenicity of polysaccharide-protein conjugate vaccines was investigated in infant baboons. MF59 consists of stable droplets (<250 nm) of the metabolizable oil squalene and two surfactants, polyoxyethylene sorbitan monooleate and sorbitan trioleate, in an oil-in-water emulsion. In humans, MF59 is well tolerated and enhances the immunogenicity of recombinant protein subunit or particle vaccines. Its effect on the immunogenicity of polysaccharide-protein conjugate vaccines is unknown. Baboons 1 to 4 months of age were immunized intramuscularly with Neisseria meningitidis group C and Haemophilus influenzae type b (Hib) oligosaccharide-CRM197 conjugate vaccines. The lyophilized vaccines were reconstituted with phosphate-buffered saline (PBS), Al(OH)3 (alum), or MF59. Groups of five animals each were given three injections of the respective formulations, with one injection every 4 weeks. Four weeks after each immunization, the MF59 group had up to 7-fold-higher geometric mean anticapsular-antibody titers than the alum group and 5- to 10-fold-higher N. meningitidis group C bactericidal-antibody titers. Twenty-one weeks after the third immunization, the MF59 group still showed 5- to 10-fold-higher anticapsular-antibody titers. The antibody responses of the animals given the vaccines reconstituted with PBS were low at all times measured. Both the MF59 and alum groups, but not the PBS group, showed booster antibody responses to unconjugated Hib and N. meningitidis group C polysaccharides, results consistent with induction of memory B cells. Thus, MF59 may be useful for accelerating and augmenting immunity to polysaccharide-protein conjugate vaccines in infants.  相似文献   

4.
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.  相似文献   

5.
Three major sources of variation affecting serum cholesterol and serum total lipid concentration values were studied in a group of healthy men. The first source of variation, analytic error, was separated into pre-instrumental and instrumental components. The pre-instrumental component, which consisted of all uncertainties occurring from the instant of venipuncture to the entrance of the sample into the instrument, was statistically significant for total lipids. The second major source of variation-preparation of the subject-was evaluated for four major stresses: diet, exercise, posture prior to venipuncture, and duration of tourniquet application. Diet affected total lipids, while the specifics of posture and tourniquet application were statistically significant for both serum cholesterol and total lipids. The third source of variation considered was the within-day and the day-to-day changes. Within-day changes were divided into within-hour and hour-to-hour effects. Day-to-day changes occurred over a two-week period. The magnitude and statistical significance of the changes were evaluated using an ANOVA model. The C.V.'s of day-to-day changes for cholesterol and total lipids (biologic) were 5.3% and 10.2%, respectively while the hour-to-hour within-day C.V.'s were 3.8% for cholesterol and 10.4% for serum total lipids. In all cases the biologic variation was in far excess of the analytic variation. The significance of these factors affecting intraindividual variation in healthy subject is discussed.  相似文献   

6.
OBJECTIVE: To determine the total and functional serogroup C antibody response to a quadrivalent meningococcal polysaccharide vaccine in a group of aboriginal infants, children and adolescents. A secondary objective was to determine their prevalence of meningococcal carriage. DESIGN: Open prospective, before and after intervention study. SUBJECTS: Aboriginal children ages 0.5 to 19.9 years, living in a single Northern community and eligible for a public health immunization campaign conducted in all Manitoba native reserve communities to control a meningococcal serogroup C, electrophoretic type (ET) 15 outbreak. No outbreak cases had occurred in the community at the time of the study. METHODS: Total serogroup C capsular polysaccharide antibody (CPA) and functional bactericidal antibody (BA) responses were measured by enzyme-linked immunosorbent assay and bactericidal assay, respectively. RESULTS: Neisseria meningitidis was recovered from the oropharynx of 13 (5.2%) of 249 aboriginal children including 4 (1.6%) serogroup C isolates, all with the designation C:2a:P1.2,5 ET15. Paired sera from 152 children were available for assay. For CPA the geometric mean concentrations and proportions with > or =2 microg/ml before and after immunization were 0.69, 18% and 12.3, 96%, respectively. A significant increase in serum CPA was achieved by children of all ages, with the greatest response occurring after age 11 years. Among infants < lyear old 89% achieved concentrations of > or =2 microg/ml. For BA the pre- and post-vaccine geometric mean titers were 1.02 and 45.9. The response was significantly associated with age. BA titers > or =1:8 were present, before and after immunization, respectively, in 0 and 0% of infants <1 year old, 0 and 20% of 1- to 1.4-year-olds, 0 and 50% of 1.5- to 1.9-year-olds and 1 and 100% of > or =2-year-olds. CONCLUSION: The age-related total and functional group C meningococcal antibody response after quadrivalent polysaccharide vaccine among aboriginals is similar to that reported for Caucasian children. After age 2 all children made excellent CPA and BA responses. In the younger age groups the BA response was blunted but 82 to 95% achieved CPA titers of > or =2 microg/ml.  相似文献   

7.
A monoclonal antibody (mAb h-448) was prepared after cell fusion of mouse myeloma cells (SP2/0-Ag-14) to the spleen cells of mice immunised with serotype h strain (MF25) of Streptococcus downei. The antibody (IgM class) reacted in enzyme immunoassay only with whole cells as well as purified polysaccharide (PS) antigen of Streptococcus sobrinus (types d and g) and Streptococcus downei (serotype h), but not with cells or purified PS antigen from any other serotypes of the mutans group of streptococci. mAb h-448 also quantitatively precipitated in solution with the purified antigens. Competitive hapten inhibition tests demonstrated that beta-methylgalactopyranoside inhibited the reaction most strongly. Although rhamnose also showed a substantial inhibitory effect, the results of this study indicate that the antigenic determinant of the PS antigen has a structure similar to the beta-methylgalactopyranoside molecule.  相似文献   

8.
Patients who are bridged-to-transplantation with mechanical support have a high incidence of pretransplant sensitization defined by panel reactive antibody (PRA) titers greater than 10. Risk factors for positive PRA in patients with assist devices were investigated. From 1993 to 1997, 17 patients underwent implant surgery with CardioWest C-70 total artificial hearts (TAHs; CardioWest Technologies, Inc., Tucson, AZ), and 13 with Novacor left ventricular assist systems (LVASs; Baxter Healthcare, Novacor Division, Oakland, CA) for bridge-to-transplantation at this institution. Two patients died during implantation of the assist devices. Of the remaining 28 patients, four (14%) were women (3 with TAHs and 1 with an LVAS). All four women (100%) had a positive PRA, whereas only two of the 24 men (8%) had positive PRA (p < 0.0001). The transfusion histories of these patients were reviewed. Using chi-squared analysis (alpha = 0.05), the PRA levels were independent of transfusion of packed red blood cells and fresh frozen plasma. There was an association, however, between platelet transfusions and PRA levels. The times on device awaiting cardiac transplantation were also compared between the PRA positive and PRA negative groups. The average time to transplantation for PRA positive patients was 116 days, whereas the average waiting time for the PRA negative patients was 55 days (p = 0.05). Based on these data, a female patient with consistently positive PRA (93%) after TAH implantation underwent a transplant on post implant day 25 despite a positive lymphocytotoxic crossmatch with the donor. She was treated with plasmapheresis during cardiopulmonary bypass at the time of transplantation, and with four further treatments post transplant. As of this writing, she is alive and well on our standard triple immunotherapy. Therefore, women who are bridged-to-transplantation with assist devices are at risk for positive PRA. It is recommended that patients who are bridged-to-transplantation with assist devices and have high PRA levels be treated with perioperative plasmapheresis. With this aggressive approach, it may no longer be necessary to keep patients on mechanical support for prolonged periods, but possible to perform transplants as soon as suitable donors become available.  相似文献   

9.
OBJECTIVE: The aim of this study was to investigate the possible effect of prolactin on the metabolism of androgens and estrogens in patients with prolactinoma. To accomplish this, prolactin, urinary androgen, and estrogen metabolite levels were determined. In order to indirectly evaluate the possible involvement of enzymes, the concentration ratios of precursor metabolite to product metabolite were also compared with controls. METHODS: Urine samples were obtained from 27 female patients with prolactinoma (macro, micro, and idiopathic) and from 31 age-matched normal female subjects. Urinary metabolites of 21 androgens and corticoids and 20 estrogens were analyzed by a gas chromatography-mass spectrometry system. RESULTS: In patients with prolactinoma, urinary 17-ketosteroids, and all estrogen metabolite concentrations were elevated. The ratios of delta 5/delta 4-steroids and 5 beta/5 alpha-hydrogensteroids were higher in the patients with prolactinoma than in normal female controls. In addition, no significant differences between patients and controls were observed in the precursor metabolite to product metabolite ratios relating to estrogen metabolism. CONCLUSION: Our data suggests that enhanced PRL levels have a direct effect on urinary steroid secretion and metabolism, probably due to lowered activities of 5 alpha-reductase and 3 beta-hydroxysteroid dehydrogenase in the patients with prolactinoma.  相似文献   

10.
INTRODUCTION: The different occurrence of Suicide depending on the rural/urban environment, as well as the interaction of this variable with others such as sex and age has given rise to a large quantity of investigations over the world. It was necessary to carry out in Spain an updated study of these characteristics. OBJECTIVE AND METHODS: Our purpose is to work with the raw data referred to suicide in the two last Spanish Census years. 4,619 records of suicide are requested and obtained from the Spanish National Statistics Institute registered in the years 1981 and 1991. Adjusted rates by rural/urban environment, sex and age are established and compared to each other. RESULTS AND CONCLUSIONS: Suicide rate in Spain is always higher in the cities that in the country, no matter be sex or the age group. However, there appears to be no continuous relationship between Suicide and the environment variable, since the large cities seem to confer a certain prevention. On the other hand, the feminine urban suicidal behaviour is becoming quantitatively more and more similar to those of men.  相似文献   

11.
Despite evidence that live, attenuated simian immunodeficiency virus (SIV) vaccines can elicit potent protection against pathogenic SIV infection, detailed information on the replication kinetics of attenuated SIV in vivo is lacking. In this study, we measured SIV RNA in the plasma of 16 adult rhesus macaques immunized with a live, attenuated strain of SIV (SIVmac239Deltanef). To evaluate the relationship between replication of the vaccine virus and the onset of protection, four animals per group were challenged with pathogenic SIVmac251 at either 5, 10, 15, or 25 weeks after immunization. SIVmac239Deltanef replicated efficiently in the immunized macaques in the first few weeks after inoculation. SIV RNA was detected in the plasma of all animals by day 7 after inoculation, and peak levels of viremia (10(5) to 10(7) RNA copies/ml) occurred by 7 to 12 days. Following challenge, SIVmac251 was detected in all of the four animals challenged at 5 weeks, in two of four challenged at 10 weeks, in none of four challenged at 15 weeks, and one of four challenged at 25 weeks. One animal immunized with SIVmac239Deltanef and challenged at 10 weeks had evidence of disease progression in the absence of detectable SIVmac251. Although complete protection was not achieved at 5 weeks, a transient reduction in viremia (approximately 100-fold) occurred in the immunized macaques early after challenge compared to the nonimmunized controls. Two weeks after challenge, SIV RNA was also reduced in the lymph nodes of all immunized macaques compared with control animals. Taken together, these results indicate that host responses capable of reducing the viral load in plasma and lymph nodes were induced as early as 5 weeks after immunization with SIVmac239Deltanef, while more potent protection developed between 10 and 15 weeks. In further experiments, we found that resistance to SIVmac251 infection did not correlate with the presence of antibodies to SIV gp130 and p27 antigens and was achieved in the absence of significant neutralizing activity against the primary SIVmac251 challenge stock.  相似文献   

12.
The method of equilibrium filtration described by Fazekas and Webster (7, 8) for the determination of the concentration (A) and quality (K) of influenza virus antibody molecules was modified in order to permit such determinations to be made for rubella virus hemagglutination inhibiting (HI) antibodies. The technique was used for determining the A and K values of humans with recent and past rubella infection. Sera from patients collected within 59 days after onset of rubella rash were found to have larger K values than found for sera collected therafter or from persons with past rubella infection. The difference in K values was found not to depend on the levels of IgM rubella antibodies. Therefore, sera from persons with recent and past rubella infection can be distinguished by use of this technique independently from the relative concentrations of rubella IgM and IgG HI antibodies.  相似文献   

13.
235 healthy 10-12 years old school children were randomly immunized with either a booster dose of diphtheria-tetanus-acellular pertussis (dTap) or diphtheria-tetanus (dT) vaccine. For this booster immunization designed for school children and adults, the quantities of Bordetella pertussis antigens in the dTap vaccine had been reduced to one third of those of the Infanrix vaccine (SmithKline Beecham) commonly used for infants. IgG antibodies and cell-mediated immune (CMI) responses to pertussis toxin (PT), pertactin (PRN) and filamentous hemagglutinin (FHA) were assessed by an enzyme immunosorbent assay and in vitro proliferation of peripheral blood mononuclear cells, respectively. Before immunization, 55%, 80% and 99% of children had detectable serum IgG antibodies to PT, PRN and FHA, whereas CMI response was found in 35%, 27% and 50% of children, respectively. After immunization, a 20-30-fold increase in geometric mean level (GML) of antibodies to the pertussis antigens occurred and CMI response to PT, PRN and FHA was seen in 88%, 94% and 100% of children, respectively. Adverse reactions following the immunization were rare. The results show that booster immunization with an acellular pertussis vaccine with reduced concentrations of antigens induces both antibody and CMI responses and support further studies of this pertussis vaccine in school children.  相似文献   

14.
A retrospective analysis of clinical and laboratory data was made of all in-vitro fertilization (IVF) patients with tubal pathology who had their first ever embryo transfer cycle between January 1st, 1992 and September 1st, 1996. The aim of the study was to determine the effect of the presence of a hydrosalpinx, whether or not visible by ultrasound, on pregnancy, multiple pregnancy and implantation rates in our patient population. The IVF success rate was also analysed by calculating cumulative ongoing pregnancy rates of the same patient group using the lifetime table approach. In the presence of an ultrasound-visible hydrosalpinx, rates of pregnancy and multiple pregnancy appeared reduced, but the differences were not significant. The rates of implantation, clinical implantation and ongoing implantation were significantly lower in the presence of an ultrasound-visible hydrosalpinx (odds ratios 0.33-0.46, C.I. 0.21-0.96). The cumulative chance of achieving an ongoing pregnancy after one or more IVF cycles was significantly reduced in the presence of an ultrasound-visible hydrosalpinx (relative hazard 0.36, C.I. 0.22-0.59). In the presence of a hydrosalpinx not visible by ultrasound the IVF outcome was not reduced. This retrospective study confirms that patients with hydrosalpinges have an impaired IVF outcome. Unique to this study and previously unobserved is the finding that there is a subgroup of patients with hydrosalpinges, those with ultrasound-visible hydrosalpinges, which is exclusively responsible for this impaired outcome.  相似文献   

15.
We identified the demographics of 385 health care workers (HCWs) to identify those whose chance of developing a protective response to a standard primary hepatitis B immunization series was so high that the need for testing for antibodies to hepatitis B surface antigen (anti-HBs) would be obviated following immunization. In addition, using sensitivity analysis, we analyzed the economic consequences of not determining anti-HBs titers for any individual after primary immunization and of using the Centers for Disease Control and Prevention (CDC)-recommended post-hepatitis B exposure prophylaxis for high-risk HCWs. Nonsmoking women < 50 years old with a weight-height index of < 42 had a 98.2 +/- 0.9% chance of developing a protective anti-HBs titer. Male nonsmokers < 50 years old with a weight-height index of < 29 had a 94.7 +/- 1.8% chance of a protective response. Economic analysis revealed that use of the CDC guidelines for post-hepatitis B exposure prophylaxis in male HCWs whose anti-HBs status is unknown is always more cost-effective than determining anti-HBs titers following primary immunization for those at high risk. In female HCWs, post-hepatitis B exposure prophylaxis is more cost-effective until hepatitis B exposure rats are approximately 50%. It is possible to predict who will have a high probability of developing a protective response to hepatitis B vaccine; for these people, determining postimmunization anti-HBs titers is unnecessary and not cost-effective.  相似文献   

16.
Total urinary incontinence is a difficult problem faced by the urologist. Several techniques to increase ureteral resistance have been described. The majority of them rely on intermittent catheterization for bladder emptying, especially in neurogenic incontinence. We have developed a new procedure in which a bladder flap is used to create a neourethra. This urethral extension acts as a flap valve to provide continence. Bladder emptying is accomplished by clean intermittent catheterization. Urethral lengthening with an anterior bladder-wall flap was performed in 18 patients aged a mean of 8.9 years who had neurogenic incontinence (14) or exstrophy (4). Patients with previous bladder interventions received a lateralized anterior flap. Bladder augmentation was performed in 14 of the 18 patients [detubularized ileum (11), detubularized colon (3)]. The average follow-up period is currently 29.3 months. Continence was achieved in 13 of the 18 patients (72%). Complications included urethrovesical fistulae, which developed in two patients. Two patients could not perform catheterization due to pain but had no obstruction to passage of catheter (exstrophy). Ureteral lengthening with an anterior bladder-wall flap is a useful alternative for the surgical treatment of urinary incontinence. This technique achieves a good continence rate and presents few problems with catheterization.  相似文献   

17.
Ten children (6 girls and 4 boys) who completed a protocol in which their localized brain tumors were successfully treated without cranial irradiation were referred for neuropsychological assessment. At the time of testing, they were disease free without any neuroaxis dissemination or leptomeningeal disease. Tumor types included pineoblastoma, glioblastoma, ependymoma, PNET and medulloblastoma. They had a mean age of 5 years and 8 months (SD = 1.86; range = 2.1-8.9 years) and were an average of 37.8 months post bone marrow transplant (SD = 16.42; range = 14-58 months). Neuropsychological data from this study reveal that the mean scores for this nonradiated group of children were within the average range for the following domains: academic achievement tests of reading, spelling and mathematics, verbal and visual memory, visual-motor integration, social-emotional and behavioral functioning. Furthermore, this group of children were performing within the low average range of overall Intelligence, as well as both verbal IQ/verbal reasoning and performance IQ/abstract visual reasoning. On tasks of fine motor dexterity, this group was within the low average range when using their dominant hand; however, they performed within the borderline range when using their non-dominant hand. Of note, this group of children demonstrated significant deficits within the borderline to impaired ranges on language tasks of expressive picture naming and receptive picture vocabulary.  相似文献   

18.
Niemann-Pick disease type C (NP-C) is a rare genetic disorder characterized by progressive neurodegeneration, frequent developmental delay and early death. Tissues of affected individuals accumulate large quantities of free cholesterol in lysosomes. Because cytotoxic oxygenated derivatives of cholesterol are known to form readily when cholesterol concentrations are elevated, we searched for these compounds in liver, kidney, spleen and brain from mice with the NP-C phenotype. In order of abundance, we identified 7 alpha- and 7 beta-hydroxycholesterol, 5 alpha, 6 alpha-epoxycholestan-3 beta-ol, 4 beta-hydroxycholesterol, cholest-4-en-3 beta, 7 alpha-diol and cholest-4-en-3 beta, 6 beta-diol in most tissue samples. Cholesterol concentrations in affected mice were increased 3-fold in kidney and 7- to 8-fold in spleen and liver compared to controls (all p < 0.001) but were unchanged in brain. Although oxysterol levels were markedly elevated in nonbrain tissue, the oxysterol and cholesterol concentrations increased proportionally so that oxysterols expressed as percentage of total sterols were the same for all animals (0.34 +/- 0.19% averaged over all organs in affected animals vs 0.40 +/- 0.42% in control mice). In contrast to peripheral tissue, we could not detect any increase in either absolute or relative oxysterol levels in the brains of affected and control mice (49 +/- 61 vs 53 +/- 43 micrograms/g wet weight and 0.45 +/- 0.52 vs 0.47 +/- 0.37%, respectively). Thus, brain sterols are normal in NP-C mice and it is unlikely that an accumulation of cytotoxic oxygenated derivatives of cholesterol could account for the progressive neuropathology seen in the disease.  相似文献   

19.
42 Down's syndrome (DS) children, age 30–42 mo, were seen in M. D. Ainsworth and B. A. Wittig's (1969) "strange situation" to assess the interrelationships among the affiliative, attachment, and fear/wariness behavioral systems. A stranger evoked affiliative behaviors in Ss but also elicited wariness and attachment behaviors. The emergence, sequence, and intensity of these behavioral systems varied with the context and the behaviors of both stranger and mother. The finding that more than one behavioral system was activated suggests that an explanation of social responsiveness must be sufficiently broad and integrative to encompass different but interrelated behavioral systems, with their respective functions and determinants. Despite certain quantitative and qualitative differences, behavioral systems appear to be similarly organized in DS and normal children. It is argued that the behavioral organization manifested by the retarded children supports and extends E. Zigler's (see record 1969-08608-001) "developmental" position. These findings suggest that the DS group constitutes a legitimate target of research for elucidating the processes of normal and deviant development. (43 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   

20.
The purpose of this study was to assess the delivery to the lungs and the short-term safety of recombinant human deoxyribonuclease (rhDNase, Pulmozyme) in children with cystic fibrosis younger than 5 years of age compared with older children. Patients between the ages of 3 months and 10 years had bronchoscopic examination with bronchoalveolar lavage (BAL) after administration of an aerosol dose of 2.5 mg of rhDNase. After recovery from the procedure, patients were discharged home for an additional 13 days of rhDNase therapy. During this time adverse events were recorded to assess short-term safety. A total of 98 patients were enrolled, 65 (66%) aged 3 months to 5 years and 33 (34%) aged 5 years to 10 years. Deoxyribonuclease concentrations in BAL fluid were variable (interquartile range, 752 to 3943 micrograms/mL epithelial lining fluid [ELF]) and did not depend on patient age, weight, or height or differ when delivered through a mouthpiece or mask. The median value for the BAL DNA concentration in the younger group was 432 micrograms/mL ELF compared with 703 micrograms/mL ELF in the older patients. This study demonstrates the value of bronchoscopy and BAL for assessing nebulized medication delivery in young children and shows that aerosolized medications can be delivered to and are present in comparable amounts in the lower airways of younger and older children. Exposure to rhDNase appears to be safe over 2 weeks in infants and young children with cystic fibrosis.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号