SEARCH · PubMed Health

Results for “Cross Protection”

Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 1,549 records · Page 86Linked to original sources

PubMed1992

Effect of passive immunization with purified specific or cross-reacting immunoglobulin G antibodies against Treponema pallidum on the course of infection in guinea pigs.

Whole immune serum or highly purified immunoglobulin G (IgG) antibodies to Treponema pallidum exhaustively adsorbed with three strains of nonpathogenic treponemes (TPI-IgG) were used for passive immunization of inbred strain 2 guinea pigs before and after intradermal challenge with 3.4 x 10(7) virulent T. pallidum Nichols organisms. Before challenge, control animals received a similarly purified IgG fraction containing either a cocktail of antibodies against three nonpathogenic treponemes (NPTI-IgG) or IgG prepared from normal guinea pig serum (NGPS-IgG). The purified fractions contained both IgG1 and IgG2 isotypes. The antibody levels (detected by fluorescent treponemal antibody test and enzyme-linked immunosorbent assay) and molecular specificities (immunoblot) of sera obtained from recipient animals before infection reflected those of the purified fractions used for immunization. Three protocols of passive immunization were used. Whole immune serum containing specific and cross-reacting antibodies afforded better protection than TPI-IgG even though asymptomatic animals were not fully protected. A single intradermal injection (0.1 ml) of TPI-IgG or NPTI-IgG into one hind leg 22 h before infection at the same site provided relatively higher protection than multiple intravenous injections (total, 15 ml) of the respective individual preparations. Since purified NGPS-IgG injected in the same animals, into the opposite hind leg, failed to protect against the challenging infection, it is reasonable to assume that specific and cross-reacting antitreponemal antibodies of the IgG1 subclass, which in guinea pigs are homocytotropic, play a relevant role in local protection.

Animals↗

PubMed2020

Distinct roles of BRCA2 in replication fork protection in response to hydroxyurea and DNA interstrand cross-links.

DNA interstrand cross-links (ICLs) are a form of DNA damage that requires the interplay of a number of repair proteins including those of the Fanconi anemia (FA) and the homologous recombination (HR) pathways. Pathogenic variants in the essential gene BRCA2/FANCD1, when monoallelic, predispose to breast and ovarian cancer, and when biallelic, result in a severe subtype of Fanconi anemia. BRCA2 function in the FA pathway is attributed to its role as a mediator of the RAD51 recombinase in HR repair of programmed DNA double-strand breaks (DSB). BRCA2 and RAD51 functions are also required to protect stalled replication forks from nucleolytic degradation during response to hydroxyurea (HU). While RAD51 has been shown to be necessary in the early steps of ICL repair to prevent aberrant nuclease resection, the role of BRCA2 in this process has not been described. Here, based on the analysis of BRCA2 DNA-binding domain (DBD) mutants (c.8488-1G>A and c.8524C>T) discovered in FA patients presenting with atypical FA-like phenotypes, we establish that BRCA2 is necessary for the protection of DNA at ICLs. Cells carrying BRCA2 DBD mutations are sensitive to ICL-inducing agents but resistant to HU treatment consistent with relatively high HR repair in these cells. BRCA2 function at an ICL protects against DNA2-WRN nuclease-helicase complex and not the MRE11 nuclease that is implicated in the resection of HU-induced stalled replication forks. Our results also indicate that unlike the processing at HU-induced stalled forks, the function of the SNF2 translocases (SMARCAL1, ZRANB3, or HLTF), implicated in fork reversal, are not an integral component of the ICL repair, pointing to a different mechanism of fork protection at different DNA lesions.

BRCA2 Protein↗

PubMed2003

Salmeterol versus sodium cromoglycate for the protection of exercise induced asthma in children--a randomised cross-over study.

OBJECTIVE: Physical activity is an important and frequent trigger of airways obstruction in asthmatic children. We aimed to compare the efficacies of 50 microg salmeterol twice daily and 2 mg SCG four times daily with respect to protection from exercise induced bronchoconstriction (EIB). METHODS: Twenty seven children and adolescents aged 4 to 16 years with mild or moderate exercise induced asthma (FEV1 70% to 90% predicted) were admitted to the study. Exercise challenge was performed on a treadmill using a predefined protocol in order to produce 10 minutes of exercise at near-maximum targets. The trial had a randomised, cross-over design comprising a 3-day run-in period and two 7-day treatment periods, separated by a one-week washout period. RESULTS: The mean protective efficacy of salmeterol was larger than that of SCG. A difference between treatments of 39.7% (95% CI, - 0,8 to 68.9%) in favour of salmeterol was calculated using a Hodges-Lehmann-estimate. The maximum post-challenge fall in FEV subset 1 was significantly lower (p<0.001) after salmeterol than after SCG (- 5.6 +/- 6.4% vs. -12.1 +/- 9.3%, respectively). In addition, salmeterol improved base-line lung function to a greater degree than SCG. FEV1 increased by 0.4 l/sec after salmeterol, whereas no improvement was observed after SCG. CONCLUSIONS: A one-week treatment with salmeterol 50 microg b.i.d in asthmatic children and adolescents provided better protection against EIB and improved baseline lung function as compared to SCG four times daily.

Adolescent↗

PubMed1997

Expression of a viral protein by muscle cells in vivo induces protective cell-mediated immunity.

Intramuscular injection of plasmid DNA expression vectors results in transfection of myocytes in situ. To determine whether expression of antigen by myocytes is sufficient to induce protective cell-mediated immunity, stably transfected myoblasts expressing influenza nucleoprotein (NP) were transplanted into mice. These animals produced high-titer anti-NP antibodies and MHC class I-restricted cytotoxic T lymphocytes, and were protected from a cross-strain lethal challenge with influenza A virus. Therefore, antigen expression by muscle cells in vivo is sufficient to confer protective cell-mediated immunity.

Animals↗

PubMed1978

Effect of cross-clamp time, temperature, and cardioplegic agents on myocardial function after induced arrest.

To evaluate the importance of time, temperature, and cardioplegia on the ability of the canine myocardium to maintain functional and ultrastructural integrity following induced arrest, we studied 220 dogs by varying myocardial temperature (34 degrees, 24 degrees, and 11 degrees C.), arrest time (0 to 120 minutes), and cardioplegic agents. Change in left ventricular function (LVF) was defined as the arithmetic difference in the center of mass between prearrest and postarrest LVF curves and was expressed as percent recovery of left ventricular stroke work. Left ventricular biopsies were obtained for semiquantitative electron microscopic analysis. After 90 minutes of cross-clamping, only hearts protected with combined hypothermia (H) and potassium-induced cardioplegia (K) significantly recovered prearrest function (24 degrees C.--80 percent, 11 degrees C.--99 percent). Hypothermia (H) alone for 90 minutes was less protective (24 degrees C.--49 percent, 11 degrees C.--59 percent). H preserved 84 percent of function after 60 minutes and 91 percent after 45 minutes. Normothermic arrest resulted in only 39 percent return of function at 45 minutes but could be extended with potassium-induced cardioplegia(K) to 78 percent at 60 minutes and 54 percent at 90 minutes. The addition of procaine plus HK improved protection over HK alone (95 percent versus 80 percent) but by itself was not effective. Neither hydrocortisone nor pretreatment with glucose-insulin-potassium, branched chain amino acids, or propranolol increased the protective effect of HK plus procaine. Inadequately protected groups (normothermia or H without K) showed more myocytic and capillary endothelial damage than the HK groups. No technique of myocardial protection studied completely preserved LVF, but the combination of HK plus procaine resulted in maximal recovery of LVF following cross-clamping for up to 120 minutes.

Animals↗

PubMed2006

Self-reported injury history in Native American professional rodeo competitors.

OBJECTIVE: Evaluation of rodeo injury and the use of protective equipment. DESIGN: Cross-sectional survey. SETTING: Indian National Finals Rodeo 2004 in San Jacinto, CA. PARTICIPANTS: One hundred sixty-nine native American, professional rodeo competitors. ASSESSMENT: On-site survey completed before competition. A total of 180 native American competitors received the survey. Respondents reported the event of participation, prior injury histories (including number, type and disability), use of protective equipment, and access to health care. MAIN OUTCOME MEASUREMENTS: Main outcomes were determined before survey distribution and included self-reported injury rate, time away from rodeo secondary to injury, and protective equipment usage during competition. RESULTS: Total 94% response rate. There was a range of injury history-from 100% of bull riders to only 24% of tie-down ropers-reporting a history of injuries. Forty percent of competitors reported using protective equipment; of these, 32% reported wearing vests. Twenty-six percent of the competitors had a history of injury that prevented them from working an average of 3.2 months. CONCLUSIONS: As hypothesized, a greater injury rate resulted from rough stock events; older competitors are more likely to have had work time loss from injury; and vests are the most frequently used protective equipment in rodeo.

Accidents, Occupational↗

PubMed1995

Evaluation of pig lungs following an experimental challenge with Actinobacillus pleuropneumoniae serotype 1 and 5 in pigs inoculated with either hemolysin protein and/or outer membrane proteins.

Histopathological changes were compared in pigs challenged with Actinobacillus pleuropneumoniae serotype 1 and serotype 5 after inoculation with subunit vaccines. The vaccines consisted of outer membrane protein and/or hemolysin protein isolated from Actinobacillus pleuropneumoniae serotype 1 or both subunits combined. Twenty-seven cross-bred pigs were separated into six groups: Groups I and IV were vaccinated and boostered with 1500 micrograms outer membrane protein; Groups II and V were vaccinated and boostered with 250 micrograms hemolysin protein; Groups III and VI were vaccinated and boostered with a combination of 1500 micrograms outer membrane protein and 250 micrograms hemolysin protein. Groups I, II and III were challenged with A. pleuropneumoniae serotype 1; and Groups IV, V and VI were challenged with A. pleuropneumoniae serotype 5. Groups III and VI demonstrated the least severe lung tissue damage, with significantly lower (P < 0.05) lung involvement as compared to the other groups. Lesions were noted in all six groups. These results showed that complete protection against A. pleuropneumoniae infection was not feasible using a subunit vaccine consisting of just outer membrane protein and hemolysin protein, and that some cross-protection did occur.

Actinobacillus Infections↗

PubMed2000

Highly regioselective synthesis of 3,4-disubstituted 1H-pyrrole.

A highly regioselective method for the synthesis of 3, 4-disubstituted 1H-pyrroles has been developed employing the ipso-directing property of a trimethylsilyl group. As a key starting material in this study, the known 3,4-bis(trimethylsilyl)-1H-pyrrole (3), was protected with carefully chosen groups, namely tert-butoxycarbonyl, N,N-dimethylaminosulfonyl, p-toluenesulfonyl, and triisopropylsilyl. A highly regioselective monoiodination of these 1-protected pyrroles was achieved by reaction with iodine-silver trifluoroacetate at low temperatures. Subsequent palladium-catalyzed cross-coupling reactions afforded 1-protected-4-substituted 3-trimethylsilyl-1H-pyrroles, which again underwent further room-temperature ipso-iodination and palladium-catalyzed cross-coupling reactions to provide symmetrical and unsymmetrical 1-protected-3,4-disubstituted 1H-pyrroles. Deprotection of 1-(tert-butoxycarbonyl) and 1-(N, N-dimethylaminosulfonyl) groups was found to be nontrivial. The 1-(p-toluenesulfonyl) protecting group was eventually proved to be superior to other protection groups, because it was readily removed after stepwise ipso monoiodinations and palladium-catalyzed cross-coupling reactions.

Pyrroles↗

PubMed1984

DNA-protein interactions in the Drosophila virilis mitochondrial chromosome.

The location of proteins on the mitochondrial DNA (mtDNA) of Drosophila virilis was investigated by Me3 psoralen photoreaction of mitochondria isolated from embryos. After photoreaction the mtDNA was purified and the pattern of DNA cross-linking was determined by electron microscopy of the DNA under totally denaturing conditions. The transcribed regions of the mtDNA molecule contained some uncross-linked regions, but such regions were infrequent and randomly distributed. In contrast, the A + T-rich region around the origin of replication of the mtDNA was usually protected from psoralen cross-linking. The data were best fit by two protected sites, each approximately 400 base pairs, compared to the four 400 base pair sites observed in the equivalent region of D. melanogaster mtDNA [Potter et al. (1980) Proc. Nat. Acad. Sci. USA 77, 4118-4122]. Thus this region of the mtDNA appears to be involved in a DNA-protein structure that is highly conserved even though the DNA sequence has diverged rapidly relative to protein-coding sequences.

Animals↗

PubMed2004

Active immunization against murine TNFalpha peptides in mice: generation of endogenous antibodies cross-reacting with the native cytokine and in vivo protection.

New lines of treatment targeting cytokines have been successfully developed recently and are now widely used in therapy. They are based on passive administration of cytokine inhibitors either soluble receptors or mAbs and the major example is TNFalpha in rheumatoid arthritis (RA). Since a few years, our group has developed a novel alternative approach targeting cytokines by using active immunization against biologically inactive but immunogenic cytokine derivatives. In the present work, we present a new aspect of this research, based on immunization against specific cytokine peptides chosen by molecular modelling. We could elicit a significant humoral response against four TNFalpha peptides by active immunization, and show that the Abs generated cross-reacted with the native cytokine with good titers as determined by ELISA. Interestingly, during coimmunization experiments with couples of peptides, one showed a clear immunodominant effect over the other. Overall, we could not show the neutralization of TNFalpha biological activity in vitro by the immunized sera, but it seems that it is not a prerequisite to observe clinical efficacy. Indeed, using the LPS/galactosamine-induced shock, we could demonstrate that one of the four peptides tested conferred a clinical protection. These results validate the feasibility and efficacy of active immunization against cytokine peptides, and confirm that active immunization against cytokines could represent in the future an alternative to passive immunization in many diseases.

Amino Acid Sequence↗

PubMed2006

Role of CD4+ T cells in a protective immune response against Cryptococcus neoformans in the central nervous system.

Cryptococcosis is a life-threatening disease caused by the encapsulated yeast, Cryptococcus neoformans. Although infection with C. neoformans is initiated in the lungs, morbidity and mortality is mostly associated with infections of the central nervous system (CNS). Individuals with deficiencies in cell-mediated immunity, such as patients with AIDS, are more susceptible to disseminated cryptococcosis, highlighting the importance of cell-mediated immunity and CD4+ T cells in host resistance against C. neoformans. Using a mouse model of cryptococcal meningoencephalitis, we have shown that immunization of mice with a cryptococcal antigen induced a protective immune response that crossed the blood-brain barrier and initiated an immune response directly in the CNS if C. neoformans was present. The regional protective response was characteristic of a Type-1 (Th1) response in the types of cells present at the site of infection and in the cytokines and chemokines expressed. Here, we extend those findings and report that CD4+ T cells are required for survival of immune mice infected directly in the brain with C. neoformans and sensitized CD4 + T cells can transfer partial protection to naive mice infected intracerebrally with C. neoformans. Furthermore, CD4 + T cells were also important for optimal infiltration of inflammatory cells at the site of infection and in the expression of cytokines and chemokines associated with protection in the brain. Lastly, CD4+ T cells were required for optimal regional production and secretion of IFNgamma and in the significantly increased expression of iNOS in C. neoformans-infected brains of immune mice.

Adoptive Transfer↗

PubMed1999

Human MxA protein protects mice lacking a functional alpha/beta interferon system against La crosse virus and other lethal viral infections.

The human MxA protein is part of the antiviral state induced by alpha/beta interferon (IFN-alpha/beta). MxA inhibits the multiplication of several RNA viruses in cell culture. However, its antiviral potential in vivo has not yet been fully explored. We have generated MxA-transgenic mice that lack a functional IFN system by crossing MxA-transgenic mice constitutively expressing MxA with genetically targeted (knockout) mice lacking the beta subunit of the IFN-alpha/beta receptor (IFNAR-1(-/-) mice). These mice are an ideal animal model to investigate the unique antiviral activity of human MxA in vivo, because they are unable to express other IFN-induced proteins. Here, we show that MxA confers resistance to Thogoto virus, La Crosse virus, and Semliki Forest virus. No Thogoto virus progeny was detectable in MxA-transgenic mice, indicating an efficient block of virus replication at the primary site of infection. In the case of La Crosse virus, MxA restricted invasion of the central nervous system. In contrast, Semliki Forest virus multiplication in the brain was detectable in both MxA-expressing and nonexpressing IFNAR-1(-/-) mice. However, viral titers were clearly reduced in MxA-transgenic mice. Our results demonstrate that MxA does not need the help of other IFN-induced proteins for activity but is a powerful antiviral agent on its own. Moreover, the results suggest that MxA may protect humans from potential fatal infections by La Crosse virus and other viral pathogens.

Alphavirus Infections↗

PubMed1997

[Description of the habits of agricultural workers in relation to the applying of pesticides].

OBJECTIVES: To find the habits of farm-workers when they apply these products, to detect dangerous practices, to find the most important defects in farm-workers' protection and to analyse the personal variables associated with the level of self-protection. DESIGN: Descriptive cross-sectional study. SETTING: Primary Care. Rural Health Centre. PARTICIPANTS: Farm-workers and spouses in our Health Area who underwent a health examination. MEASUREMENTS AND MAIN RESULTS: A questionnaire was designed specifically for the study and filled out by the doctor or nurse at the centre where the person interviewed was registered. 72.8% of the farm-workers had inadequate protection. 79.3% said they had suffered on some occasion symptoms related to pesticide use. CONCLUSIONS: In the rural health areas where there is intensive agriculture, exposure to pesticides is a major health problem, as these substances are hazardous and people applying them wear inadequate protection. Action strategies in this field involve integrating health at work services into health centres. Health education tasks have to be coordinated with the agricultural organisations in the area, such as associations for the defense of plants, cooperatives, etc.

Agricultural Workers' Diseases↗

PubMed1993

Reactivity and protective capacity of a polyclonal antiserum derived from mice immunized with antibiotic exposed Escherichia coli.

The murine immune response to Escherichia coli O6:K-alone or pre-exposed to 0.1 x MIC of aztreonam was investigated. Relative to mice immunized with untreated bacteria, mice immunized with antibiotic-treated microorganisms presented a significantly enhanced protection towards a challenge of 100 x LD50 of viable E. coli O6:K-. Previous injection of 0.1 mL of serum drawn from mice immunized with treated and untreated bacteria protected non-immunized mice towards a challenge of 10 x LD50 of viable E. coli O6:K--. Serum from mice immunized with treated bacteria also protected non-immunized mice towards a lethal challenge of E. coli O111. The antiserum contained high titre of IgG antibodies that cross-reacted with lipopolysaccharide isolated from smooth and rough Gram-negative bacteria. Immunoblotting showed additional bands of reactivity to the untreated E. coli O6:K-. Immunization with antibiotic-treated bacteria led to the production of type specific and cross reactive antibodies that protected animals against viable homologous and heterologous lethal challenges.

Animals↗

PubMedDate not supplied

[Prevention of risk of cross-infection through the respiratory system during anesthesia].

The authors present a modern concept of prevention of cross contamination during forced ventilation of the lungs in the course of total anesthesia and operation. The optimal complex of measures of individual protection of a patient includes hygienic measures, use of sterile respiratory systems (better disposable), obligatory use of respiratory filters between the intubation tube and T-piece of the narcosis and respiration device; hydrophobic folded membrane filters should be preferred. Studies carried out at Anesthesiology Department of Research Center of Surgery of Russian Academy of Medical Sciences indicate that BB 22-15 filters (Pall Corporation) reliably protect patients from cross-contamination realized through respiratory gases and biological fluids (blood, saliva, condensate) and save heat and humor. Hydrophobic folded membrane filter BB 22-15 is highly effective, which recommends it for wide use.

Adult↗

PubMedDate not supplied

Myocardial protection in coronary artery bypass surgery. A study comparing cold cardioplegia and intermittent aortic cross clamping.

Twenty patients having elective coronary artery bypass surgery were randomized for myocardial protection during cardiopulmonary bypass with cold cardioplegia and topical deep hypothermia with the Bretschneider solution in one group and intermittent aortic cross clamping at 30 degrees C in another group. The cardioplegic group showed more consistent results with lower CK-MB elevations both in terms of peak values and areas under the time-enzyme activity curves, although no statistical significance was obtained. There were significantly more infarct suspect time-enzyme activity curves in the intermittent cross clamping group (4 vs. O), and therefore, cold cardioplegia is advocated in preference to intermittent cross clamping in coronary artery bypass surgery.

Aorta↗

PubMed1987

Immunological cross-reactivity between preS2 sequences of the hepatitis B virus envelope proteins corresponding to serological subtypes adw2 and ayw.

An immune response to epitopes localized on the preS region of the hepatitis B virus (HBV) envelope (env) is elicited during recovery from HBV infection and appears to play a role in virus clearance. Anti-preS antibodies (Ab) are expected to be protective against HBV infection as indicated by the virus-neutralizing capacity of Ab to a preS2-specific synthetic peptide preS(120-145). However, there is considerable amino acid variability between preS regions corresponding to distinct serological subtypes of HBV, raising the question whether the preS sequences are sufficiently related immunologically to have the potential of inducing cross-protective immunity. To answer this question concerning the preS2 region, antisera to synthetic peptides preS(120-153) and preS(128-153) corresponding to subtypes adw2 and ayw, as well as to the native env [ayw] protein were raised. Using the resulting polyclonal Ab, an immunological relatedness between preS2 sequences of subtypes adw2 and ayw was demonstrated. On the other hand, Ab selected by affinity chromatography or by cloning hybridoma cells may recognize with strong preference subtype-specific determinants within the preS2 region when the compared antigens are in solution rather than on the solid phase. These findings have implication for the design of: (1) preS2-specific immunogens and (2) immunoassays for quantitation of preS2 sequences in HBV env proteins.

Amino Acid Sequence↗

PubMed1998

HIPAA Newborns' and Mothers' Health Protection Act--IRS. Notice of proposed rulemaking by cross-reference to temporary regulations.

Elsewhere in this issue of the Federal Register, the IRS is issuing temporary regulations relating to minimum hospital length-of-stay requirements imposed on group health plans with respect to mothers and newborns. The hospital length-of-stay requirements were added to the Internal Revenue Code by section 1531 of the Taxpayer Relief Act of 1997. The IRS is issuing the temporary regulations at the same time that the Pension and Welfare Benefits Administration of the U.S. Department of Labor and the Health Care Financing Administration of the U.S. Department of Health and Human Services are issuing substantially similar interim final regulations relating to hospital length-of-stay requirements added by the Newborns' and Mothers' Health Protection Act of 1996 to the Employee Retirement Income Security Act of 1974 and the Public Health Service Act. The temporary regulations provide guidance to employers and group health plans relating to the new hospital length-of-stay requirements. The text of those temporary regulations also serves as the text of these proposed regulations.

Delivery, Obstetric↗