The abdomen
Peter Kopelman, Dame Jane Dacre in Handbook of Clinical Skills, 2019
Hepatitis serology The serological markers of hepatitis B are important in assessing the relative infection risk of carriers. In a patient incubating hepatitis B, or with an acute attack, there are positive tests for HbsAg (surface antigen) and HbeAg (a marker of high infectivity). The patient may also have the antibodies anti-Hbc, immunoglobulin (Ig) G and IgM. In the carrier state, HbsAg is positive. HbeAg is either positive or negative, depending on whether the patient is highly (positive HbeAg) or not very highly (negative HbeAg) infectious. In the convalescence phase of an acute attack, the HbsAg and HbeAg are negative, but anti-Hbs and anti-Hbi antibodies become positive. After successful vaccination, the patient is positive for anti-Hbs only. The presence of viraemia should be confirmed by quantifying hepatitis B viral DNA in the blood. Evidence of previous hepatitis C virus infection is indicated by serology with quantification of viral RNA in the blood and genotyping to guide therapy.
Human Hepatitis Viruses A and B as Etiological Agents of a Hemorrhagic State
James H. S. Gear in CRC Handbook of Viral and Rickettsial Hemorrhagic Fevers, 2019
There is a short time during acute HBV hepatitis when the HBsAg test may be negative. It is therefore advisable to supplement the test with an anti-HBc, preferably an anti-HBc(IgM) test to demonstrate infection. Only a minority of patients will be in this transient phase, however, and the greater majority will be diagnosable by the HBsAg test. Carriers have HBsAg, may have HBeAg and polymerase or not, and have anti-HBc (not IgM). They do not have abnormal liver function tests caused by the HBV, but, of course, may show such abnormalities if caused by a VHF infection, mimicking HBV-caused hemorrhagic disease. The anti-HBc(IgM) is the most useful test for solving this problem, being positive only in acute, active HBV infection or shortly afterwards. Another point may be the finding of the combination HBeAg positive and/or polymerase positive, anti-HBe negative, which is more in favor of an acute infection, although active, infectious carriers, especially in the Far East, may retain the same markers indefinitely.
Hepatitis B virus
Peter M. Lydyard, Michael F. Cole, John Holton, William L. Irving, Nino Porakishvili, Pradhib Venkatesan, Katherine N. Ward in Case Studies in Infectious Disease, 2010
HBV infection can be prevented by means of vaccination, using the HBsAg as the immunizing antigen. Original vaccines consisted of HBsAg purified from human plasma, and plasma-derived vaccines are still used in some parts of the world. However, in Europe and the USA the current vaccines are subunit vaccines prepared by recombinant DNA technology. The gene encoding the HBsAg has been cut out of the virus and inserted into a yeast. As the yeast replicates in culture, large amounts of HBsAg are synthesized within the cytoplasm of the cell. Cell lysis followed by purification yields HBsAg, which is administered by intramuscular injection (usually as a course of three injections given at 0, 1, and 6 months). As the only part of the virus present in the vaccine is HBsAg, the response to the vaccine can be easily measured by quantifying the anti-HBs in the vaccinee 6–8 weeks after the last dose. Protection against HBV infection is proportional to the amount of anti-HBs produced. Around 10% of adults do not mount an anti-HBs response to this vaccine and therefore remain susceptible to infection. A further 10% will make a rather weak response, which may offer only limited protection.
Gold nanoparticles and hepatitis B virus
Published in Artificial Cells, Nanomedicine, and Biotechnology, 2019
Babak Negahdari, Mohammad Darvishi, Ali Asghar Saeedi
There have been quite few research studies that demonstrated the application of gold nano-particles in detecting hepatitis B virus [28]. Gold nano-rod (GNR) have been used to develop biosensor for detecting hepatitis B surface antigen (HBsAg) in biological sample or specimen such as buffer, blood serum and plasma [29]. HBsAg is considered the most crucial biomarker for the lab-based diagnosis of hepatitis B virus. The presence of HBsAg in the blood or serum sample signifies a chronic and acute level of hepatitis B virus infection [30,31]. The operating principle involves labeling the GNR surface with a monoclonal HBsAb to detect HBsAg and the technique was validated via ELISA [32]. Integrating the antibody with concentrated GNRs through nonspecific physisorption lead to the synthesis of the antibody-GNR complex (Figure 2) called the biosensor, which can characterize target proteins.
Gold nanoparticles and hepatitis B virus
Published in Artificial Cells, Nanomedicine, and Biotechnology, 2019
Babak Negahdari, Mohammad Darvishi, Ali Asghar Saeedi
There have been quite few research studies that demonstrated the application of AuNPs in detecting HBV [28]. AuNR have been used to develop biosensor for detecting hepatitis B surface antigen (HBsAg) in biological sample or specimen such as buffer, blood serum and plasma [29]. HBsAg is considered the most crucial biomarker for the lab-based diagnosis of hepatitis B virus. The presence of HBsAg in the blood or serum sample signifies a chronic and acute level of hepatitis B virus infection [30,31]. The operating principle involves labeling the AuNR surface with a monoclonal hepatitis B surface antibody (HBsAb) to detect HBsAg and the technique was validated via ELISA [32]. Integrating the antibody with concentrated AuNRs through nonspecific physisorption lead to the synthesis of the antibody-AuNR complex (Figure 2) called the biosensor, which can characterize target proteins.
Demystifying particle-based oral vaccines
Published in Expert Opinion on Drug Delivery, 2021
Pedro Gonzalez-Cruz, Harvinder Singh Gill
Although oral vaccines against many different diseases have been investigated (Figure 1B), most antigens fall into the model antigen category. These model antigens comprise OVA, bovine serum albumin (BSA), and human serum albumin (HSA). These well-documented antigens are readily available, and this has led to their extensive use in testing new delivery systems. The top 5 diseases (besides model proteins [22–41]) researched with particle-based oral delivery systems are hepatitis B [42–49], cholera [50–56], norovirus [57–64], diphtheria [65–71], and E. coli infection [9,72–77] (Figure 1B). Hepatitis B surface antigen (HBsAg) is the second most common disease investigated to make an oral vaccine. If successful, this could be a valuable oral vaccine since about 250 million people worldwide are infected with Hepatitis B, and it is the leading cause of liver cancer [78]. To carry out the in vivo studies, mice are the most commonly used species, and in particular, most articles have used BALB/c mice followed by C57BL/6 mice (Figure 1C) [9,51,54,57,58,60,66,67,70,73,79–109]. Rats, rabbits, cattle, pigs, macaques, and guniea pigs have also been used as animal models. Three human studies have been performed, and they have investigated vaccines against diphtheria and norovirus diseases [61,63,68].
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