Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0029713 (immaturity)
 4,335 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

A chronic infection develops in the vast majority of newborn infants infected with the hepatitis B virus, compared with fewer than 10% of infected adults. The reason is probably related to the immaturity of the newborn immune response to infection, resulting in failure to completely eradicate the virus from hepatocytes. Studies of the newborn immune system demonstrate a variety of defects that may predispose infants to chronic hepatitis B infection, including diminished cytokine production, decreased cytotoxic activity, and a generalized suppression of the immune response. In addition, there is evidence that exposure of the fetus to certain maternal hepatitis B antigens and antibodies may adversely modulate the newborn immune response. This article reviews the epidemiologic, virologic, and immunologic aspects of newborn hepatitis B infection, and discusses the reasoning behind the recent recommendations for universal hepatitis B vaccination of newborn infants.
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PMID:Neonatal hepatitis B infection: clinical and immunologic considerations. 816 73

Bile acid synthetic defects are uncommon disorders that cause progressive cholestatic liver disease that is often lethal in infancy or early childhood. Five specific primary defects have been described. Diagnosis is based on mass spectrometry of urine and serum. Pathogenesis of liver injury is related to persistent reduction in levels of normal bile acids and accumulation of abnormal, potentially hepatotoxic, intermediaries. Sites of injury are the liver cell, the bile canaliculus, and the smallest bile ductules. The interlobular bile ducts are normal. The liver lesion is progressive chronic hepatitis with an especially high incidence of GCT in patients who present in infancy. Bile acid replacement therapy is usually effective in arresting the liver injury. Regression of liver damage has been documented during treatment of patients who were diagnosed early in life. Because bile acid synthetic disorders are the only cholestatic diseases of infancy in which GCT of hepatocytes is consistently present, the author suggest that the injury responsible for GCT may be specific for toxic bile acids. Accordingly, immaturity of the bile acid synthetic pathway may render many otherwise normal infants vulnerable to transient "neonatal hepatitis" with GCT in a broad range of cholestatic disorders.
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PMID:Liver disease caused by disorders of bile acid synthesis. 1123 60

Little is known about the effect of chronic hepatitis B and hepatitis C on sperm quality. In this study we analysed sperm quality from selected patients with chronic hepatitis B virus (HBV) or hepatitis C virus (HCV) infections. Semen samples were examined by light and transmission electron microscopy (TEM). TEM data were elaborated with a mathematical formula able to indicate a fertility index and the presence of the three main sperm pathologies: apoptosis, immaturity and necrosis. Meiotic chromosome segregation was investigated by fluorescence in situ hybridisation carried out on sperm nuclei, using probes for chromosomes 18, X and Y. Despite normal sperm concentration, we observed reduced motility. TEM analysis highlighted that 35.7% of patients showed generally good semen quality. However, significantly higher values of apoptosis and necrosis, compared with controls, were observed, demonstrating spermatogenetic alterations. Regarding meiotic segregation, we found an incidence of disomies similar to that observed in control samples, whereas diploidy resulted higher in HCV patients, without reaching statistical significance. In conclusion, sperm quality in the studied group was not impaired, however, apoptosis and necrosis resulted out of normal range and the fertility index was significantly lower in HCV and HBV infected patients versus controls.
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PMID:Sperm ultrastructure and meiotic segregation in a group of patients with chronic hepatitis B and C. 1847 4

Little is known about the effect of chronic hepatitis B and hepatitis C on sperm quality. In this study, we analysed sperm quality from selected patients with chronic hepatitis B virus (HBV) or hepatitis C virus (HCV) infections. Semen samples were examined by light and transmission electron microscopy (TEM). TEM data were elaborated with a mathematical formula able to indicate a fertility index and the presence of the three main sperm pathologies: apoptosis, immaturity and necrosis. Meiotic chromosome segregation was investigated by fluorescence in situ hybridisation carried out on sperm nuclei, using probes for chromosomes 18, X and Y. Despite normal sperm concentration, we observed reduced motility. TEM analysis highlighted that 35.7% of patients showed generally good semen quality. However, significantly higher values of apoptosis and necrosis, compared with controls, were observed, demonstrating spermatogenetic alterations. Regarding meiotic segregation, we found an incidence of disomies similar to that observed in control samples, whereas diploidy resulted higher in HCV patients, without reaching statistical significance. In conclusion, sperm quality in the studied group was not impaired; however, apoptosis and necrosis resulted out of normal range and the fertility index was significantly lower in HCV- and HBV-infected patients versus controls.
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PMID:Sperm ultrastructure and meiotic segregation in a group of patients with chronic hepatitis B and C. 1881 18

The host immune system plays an important role in chronic hepatitis B (CHB), both in viral clearance and hepatocellular damage. Advances in our understanding of the natural history of the disease have led to redefining the major phases of infection, with the "high replicative, low inflammatory" phase now replacing what was formerly termed the "immune tolerant" phase, and the "nonreplicative phase" replacing what was formerly termed the "inactive carrier" phase. As opposed to the earlier view that HBV establishes chronic infection by exploiting the immaturity of the neonate's immune system, new findings on trained immunity show that the host is already somewhat "matured" following birth, and is actually very capable of responding immunologically, potentially altering future hepatitis B treatment strategies. While existing therapies are effective in reducing viral load and necroinflammation, often restoring the patient to near-normal health, they do not lead to a cure except in very rare cases and, in many patients, viremia rebounds after cessation of treatment. Researchers are now challenged to devise therapies that will eliminate infection, with a particular focus on eliminating the persistence of viral cccDNA in the nuclei of hepatocytes. In the context of chronic hepatitis B, new definitions of 'cure' are emerging, such as 'functional' and 'virological' cure, defined by stable off-therapy suppression of viremia and antigenemia, and the normalization of serum ALT and other liver-related laboratory tests. Continued advances in the understanding of the complex biology of chronic hepatitis B have resulted in the development of new, experimental therapies targeting viral and host factors and pathways previously not accessible to therapy, approaches which may lead to virological cures in the near term and functional cures upon long term follow-up. This article forms part of a symposium in Antiviral Research on "An unfinished story: from the discovery of the Australia antigen to the development of new curative therapies for hepatitis B."
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PMID:Chronic hepatitis B: Virology, natural history, current management and a glimpse at future opportunities. 2609 43