Variable Degrees Of Protection Research Articles

Utility of Combined Ischemic Pre- and Post-Conditioning to Protect the Human Myocardium

Objective: Ischemic pre-conditioning (IPreC) and post-conditioning (IPostC) protect the human myocardium against ischemia/reoxygenation (I/R) injury. However, the two interventions may induce variable degrees of protection, suggesting different mechanisms of action. This study assessed whether IPreC and IPostC confer greater protection when used in combination rather than individually. Methods: The right atrial appendages from 50 patients were subjected to 90 min of ischemia and 120 min of reoxygenation according to different protocols: IPostC (1 cycle of 120 and 180 sec of I/R) and IPreC (1 cycle of 5 min ischemia/5 min reoxygenation), alone and in combination. Lactate dehydrogenase (LDH) release was measured as an index of tissue injury and 3-(4,5-dimethyl thiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) reduction as an index of cell viability. Results: The results showed that in one half of muscles the combined use of IPreC and IPostC reduced injury compared to either intervention alone whereas in the remaining half the combined approach had no greater effect. Nonetheless, the addition of IPreC to IPostC increased the number of protected samples by almost 20% compared to IPostC alone. Conclusion: The results demonstrate the lack of a uniform response to IPreC and IPostC and that the combined use of the two treatments improves protection although does not abolish the further myocardial injury that occurs in some instances in response to IPostC.

Inactivated poliovirus vaccines: an inevitable choice for eliminating poliomyelitis

The inactivated poliovirus vaccine (IPV) is a very old tool in the fight against poliomyelitis. Though supplanted by oral poliovirus vaccine (OPV) in the 1960s and 1970s, the IPV has now become an inevitable choice because of the increasingly recognized risks associated with continuous use of OPVs. Following the pioneering work of Jonas Salk, who established key principles for the IPV, considerable experience has accumulated over the years. This work has led to modern Salk IPV-containing vaccines, based on the use of inactivated wildtype polioviruses, which have been deployed for routine use in many countries. Very good protection against paralysis is achieved with IPV through the presence of circulating antibodies able to neutralize virus infectivity toward motor neurons. In addition, with IPV, a variable degree of protection against mucosal infection (and therefore transmission) through mucosal antibodies and immune cells is achieved, depending on previous exposure of subjects to wildtype or vaccine polioviruses. The use of an IPV-followed-by-OPV sequential immunization schedule has the potential advantage of eliminating the vaccine-associated paralytic poliomyelitis (VAPP) risk, while limiting the risks of vaccine-derived poliovirus (VDPVs). Sabin strain-derived IPVs are new tools, only recently beginning to be deployed, and data are being generated to document their performance. IPVs will play an irreplaceable role in global eradication of polio.

How does smoking-related profile of the population influence the effectiveness of smoke-free laws? A nationwide study in Switzerland.

Introduction In Switzerland, smoking bans were implemented in different social contexts with a variable degree of protection and at different time points between 2007 and 2010. We took advantage of...

The role of genetics in the variable clinical response to different forms of malaria

There is now strong evidence that variable degrees of protection against infection with P. falciparum malaria is mediated by the carrier state for a variety of different inherited disorders of haemoglobin, genetic variation in the red blood cell membrane or metabolism, and a variety of different blood groups. Similarly, genetic factors are also involved in either increasing or decreasing the susceptibility to P. vivax malaria. Recent work has shown that there are some remarkable epistatic interactions between the different genes involved in these conditions and the resulting susceptibility to different forms of malaria. These new findings, combined with further information obtained about the genetic basis of malaria resistance based on genome-wide association studies are already leading to a better understanding of the mechanisms whereby some of these genetic disorders offer protection to different forms of malaria, the mechanism of which is still ill-understood. In addition, these new approaches are starting to provide invaluable information about the remarkably heterogeneous distribution of some of these genetic variants, notably the inherited haemoglobin disorders.

Is the adjuvanted influenza vaccine more effective than the trivalent inactivated vaccine in the elderly population? Results of a case–control study

IntroductionInfluenza illness is an important public health problem and annual vaccination is globally recommended for high risk populations. ObjectiveThe aim was to evaluate and compare the effectiveness of influenza vaccines in reducing hospitalizations for influenza or pneumonia during two influenza seasons in the elderly. MethodsA case–control study was performed, using administrative database of the Local Health Unit Roma-A (LHU RM-A). The included subjects were at least 65 years old and residing in one of the four districts of the LHU. The cases were hospitalized for influenza or pneumonia during influenza season in the years 2010–2011 and 2011–2012. The controls were hospitalized in the same period, but not for influenza or pneumonia. The subjects were immunized with the trivalent inactivated influenza vaccine (TIV) in the first influenza season (2010–2011) and with the adjuvanted influenza vaccine MF59 (ATIV) in the second season (2011–2012). ResultsA total of 269 cases and 1247 controls were included for the 2010–2011 influenza season, and 365 cases and 1227 controls were selected for the 2011–2012 season. Up to 63.6% cases and 53.5% controls in the 2010–2011 season and 78.6% of cases and 64.1% of controls in the 2011–2012 season have not been vaccinated. Female gender and high educational level were protective factors for hospitalization. Subjects over 75 years were at high risk of hospitalization compared to 65–74 years olds. Influenza vaccination reduced significantly hospitalization in both seasons. In subjects with 65–74 years TIV was more effective than ATIV; vice versa for those over 75 years old. Discussion and conclusionTIV and ATIV reduce hospitalization for influenza or pneumonia with a variable degree of protection in different age groups. In particular, ATIV is more effective in individuals over 75 years old.

Developing Plasmodium falciparum malaria vaccines for populations living in areas with stable parasite transmission

Individuals living in areas with stable transmission of Plasmodium falciparum parasites develop substantial protective immunity to the disease during childhood. Because of naturally acquired immunity, which appears mainly to target parasite-encoded Variable Surface Antigens (VSA) on the Infected Erythrocytes (IE), severe and life-threatening disease among adults in such areas is rare. However, low-grade asymptomatic parasitaemia continues to be present in a large proportion of people. So far, experimental P. falciparum malaria vaccination employing non-VSA antigens have resulted in variable degrees of protection, including sterile protection, but the duration of the protection afforded is short-lived, probably due to insufficient boosting. Based on these findings, our approach to vaccine development is to accelerate naturally acquired VSA-specific immunity. The ambition is to develop vaccines that will protect against mortality and severe morbidity, but which allow persistence of low-grade, asymptomatic infection. Hopefully, this approach will ensure regular boosting of immunity that appears necessary for the long-lasting protection required of vaccines to be deployed in malaria-endemic areas.

Immunological properties of FMDV-gP64 fusion proteins expressed on SF9 cell and baculovirus surfaces

In the present report, we characterized the immune response and the protection conferred by recombinant baculoviruses or infected insect cells expressing the fusions gp64-P1 and gp64-site A FMDV antigens. Mice, vaccinated intraperitoneally with gp64-P1 immunogens, showed a low-antibody response and a variable degree of protection. However, when mice received recombinant baculoviruses or infected insect cells expressing the fusion protein gp64-site A, high-ELISA and seroneutralizing titers (SNT) against FMDV were elicited. All mice immunized with Sf9 cells expressing FMDV site A developed a protective immune response against challenge with virulent FMDV, indicating that the baculovirus display of foreign epitopes is a promising approach to biosynthetic vaccines.

Improved immunogenicity of DNA vaccination with mycobacterial HSP65 against bovine tuberculosis by protein boosting

A scientific review for the government of the United Kingdom has recommended that the development of a cattle vaccine against bovine tuberculosis holds the best prospects to control this disease in the national herd. As BCG vaccination of cattle results in variable degrees of protection, novel vaccine strategies that could replace or supplement BCG are required. In this study, the mycobacterial antigen HSP65 was used to determine whether priming cattle with a plasmid DNA vaccine and subsequently boosting with the recombinant protein in adjuvant (heterologous prime-boost approach) would result in improved and more homogenous immune responses over immunising with plasmid DNA or protein in adjuvant alone. The results demonstrated that strong, and compared to protein or DNA vaccination protocols alone, more homogenous, cellular immune responses were induced in cattle vaccinated with the prime-boost regimen. In addition, DNA prime-protein boost vaccination as well as protein vaccination resulted in stronger humoral immune responses with a balanced IgG profile compared to DNA vaccination alone. Importantly, none of the vaccination protocols sensitised cattle to the intradermal tuberculin test suggesting that TB subunit vaccines can be designed to allow the continued use of the tuberculin test to discriminate between vaccinated cattle and those infected with Mycobacterium bovis.

Review and Critique of the Use of Immunoglobulins in Prevention and Treatment of Infection in Critically Ill Patients

The study of standard intravenous immunoglobulin G (IVIG) preparations as adjunctive therapy in seriously ill patients is motivated by the possible need to: restore immunoglobulin G levels depleted after trauma or surgery; and/or to provide patients with specific antibodies directed against various microorganisms. Whereas no therapeutic efficacy has been shown in clinical studies with standard IVIG, some data suggest a benefit in prophylactic use. Antisera or IVIG hyperimmune against the biologically active. highly conserved core portion of the endotoxin of Gram‐negative bacteria have demonstrated variable degrees of protection in animal models and clinical trials. Two clinical trials using monoclonal antibodies against core lipopolysaccharide have been completed. Only subsets of patients with the Gram‐negative sepsis syndrome were protected, but both studies gave discrepant results concerning the type of patients that were reported to benefit from administration of these antibodies. Further studies will be necessary to establish whether application of this therapy can be recommended.

Saimiri sciureus (karyotype 14-7): an alternative experimental model of Plasmodium falciparum infection.

In an earlier manuscript, we described the first phase of adaptation of the Palo Alto I strain of Plasmodium falciparum to Saimiri sciureus (squirrel monkeys). Now, after more than 50 P. falciparum blood transfers in splenectomized Saimiri, the parasite has become fully adapted to this experimental host. A highly reproducible pattern of infection is evident in these splenectomized animals, which is characterized by a rapidly rising parasitemia and a lethal outcome. In intact animals, the course of infection is extremely variable, with a tendency towards high parasitemias and low survival rates. After 60 passages, the parasites have maintained their invasiveness for human red blood cells and can easily be propagated by continuous in vitro culture. Conversely, prolonged in vitro culture of this parasite strain has not decreased its infectivity for Saimiri. Intact, P. falciparum-infected animals rapidly develop a high degree of resistance to reinfection, even when treatment is initiated shortly after detection of the first circulating parasites. Under identical conditions, splenectomized animals develop a variable degree of protection. The potential usefulness of squirrel monkeys as experimental hosts of P. falciparum and P. vivax malaria is discussed in light of the present findings.

Immunological properties of antivenins. II. Univalent Naja haje antivenin.

A purified Naja haje antivenin was tested against Egyptian N. haje and N. nigricollis venoms, Indian N. naja venom, Iranian N. naja oxiana, Vipera lebetina, and V. persica venoms, and Echis carinatus venom from both Iran and Egypt. The different elapid venoms, with the exception of that of N. naja oxiana, showed a considerable number of identical and similar precipitin components by immunodiffusion and immunoelectrophoresis. On the other hand, only a few identical and partially identical lines were detected when this antiserum was tested against the viper venoms. Cross neutralization tests in mice showed variable degrees of protection by the antiserum against the different venoms studied; there was no direct correlation with the immunodiffusion results.

Studies on Erysipelas in Turkeys

RYSIPELAS was first reported in New York State turkeys in 1938 by Van Roekel.15 Since then numerous cases of erysipelas have been found in New York5'11 and the disease is now recognized as a considerable economic problem in adult turkey flocks. In experimental work on turkey erysipelas some workers have had difficulty in maintaining virulence of Erysipelothrix rhusiopathiae cultures and obtaining a consistent and high mortality in inoculated turkeys. Adler and Spencer', Dickinson et al.6, and Moynihan and Stovell10 reported that an irregular mortality resulted when susceptible turkeys were challenged by other than the intravenous route. Adler and Spencer' also mentioned that it was difficult to maintain virulence of E. rhusiopathiae cultures that were lyophilized. Peterson and Hymas12 reported good mortality when the intramuscular route was used in non-immune turkeys. The percutaneous (skin scarification) route as originally described by Fortner and Dinter7 was found to be the only way to reproduce erysipelas in swine consistently. Some work has been done on the efficacy of vaccines for protection of turkeys. Dickinson, et al.,6 reported a variable degree of protection to experimental challenge of vaccinated field flocks. Jerstad and Johns9 reported that vaccinated flocks