Intrahepatic distribution of hepatitis B virus antigens in patients with and without hepatocellular carcinoma

AIM: To study the intrahepatic expression of hepatitis B surface antigen(HBs Ag) and hepatitis B core antigen(HBc Ag) in chronic hepatitis B patients with and without hepatocellular carcinoma. METHODS: A total of 33 chronic hepatitis B patients(mean age of 40.3 ± 2.5 years), comprising of 14 HBe Ag positive and 19 HBe Ag negative patients; and 13 patients with hepatitis B virus related hepatocellular carcinoma(mean age of 49.6 ± 4.7 years), were included in our study. Immunohistochemical staining for HBc Ag and HBs Ag was done using standard streptavidin-biotin-immunoperoxidase technique on paraffin-embedded liver biopsies. The HBc Agand HBs Ag staining distributions and patterns were described according to a modified classification system. RESULTS: Compared to the HBe Ag negative patients, the HBe Ag positive patients were younger, had higher mean HBV DNA and alanine transaminases levels. All the HBe Ag positive patients had intrahepatic HBc Ag staining; predominantly with "diffuse" distribution(79%) and "mixed cytoplasmic/nuclear " pattern(79%). In comparison, only 5% of the HBe Ag-negative patients had intrahepatic HBc Ag staining. However, the intrahepatic HBs Ag staining has wider distribution among the HBe Ag negative patients, namely; majority of the HBe Ag negative cases had "patchy" HBs Ag distribution compared to "rare" distribution among the HBe Ag positive cases. All but one patient with HCC were HBe Ag negative with either undetectable HBV DNA or very low level of viremia. Intrahepatic HBc Ag and HBs Ag were seen in 13(100%) and 10(77%) of the HCC patients respectively. Interestingly, among the 9 HCC patients on anti-viral therapy with suppressed HBV DNA, HBc Ag and HBs Ag were detected in tumor tissues but not the adjacent liver in 4(44%) and 1(11%) patient respectively. CONCLUSION: Isolated intrahepatic HBc Ag and HBs Ag can be present in tumors of patients with suppressed HBV DNA on antiviral therapy; that may predispose them to cancer development.     

Mutational analysis of ATP7B gene in Egyptian children with Wilson disease: 12 novel mutations

The aim of this work was to study the mutations within ATP7B in Egyptian children with Wilson disease and to evaluate any potential correlation between genotype and phenotype in this cohort. The study consisted of 48 children with Wilson disease from 32 independent families. The 21 exons of the ATP7B gene were amplified in a thermal cycler. Direct sequencing of the amplified polymerase chain reaction (PCR) products was performed by cycle sequencing using fluorescent dye terminators in an automatic ABI sequencer. Thirty-one different mutations in 96 chromosomes were detected (19 missense, three nonsense, seven frameshift deletions, and two splice-site mutations). Of these, 12 mutations have not been previously reported. The p.N1270S, p.C703Y, IVS18-2A > G, p.R1319X, c.2304-2305insC, and p.H1069Q were present in 7.8%, 6.2%, 6.2%, 6.2%, 4.7%, and 4.7%, respectively, of studied chromosomes in independent families. One patient was homozygous for both p.N1270S and p.T1434M mutations. Frameshift and nonsense mutations were found in 50% of patients with disease onset < or =8 years compared with only 26% in patients with onset >8 years. Despite mutation heterogeneity in Egyptian children, genotype-phenotype correlation analysis seems to be promising in this population, as many patients carry homozygous mutations, a situation that mandates a larger-scale population screening to identify the carrier rate in this community.     

Cellular accumulation of the new ketolide RU 64004 by human neutrophils: comparison with that of azithromycin and roxithromycin.

We analyzed the uptake of RU 64004 by human neutrophils (polymorphonuclear leukocytes [PMNs]) relative to those of azithromycin and roxithromycin. RU 64004 was strongly and rapidly accumulated by PMNs, with a cellular concentration/extracellular concentration ratio (C/E) of greater than 200 in the first 5 min, and this was followed by a plateau at 120 to 180 min, with a C/E of 461 +/- 14.8 (10 experiments) at 180 min. RU 64004 uptake was moderately sensitive to external pH, and activation energy was also moderate (63 +/- 3.8 kJ/mol). RU 64004 was mainly located in PMN granules (about 70%) and egressed slowly from loaded cells, owing to avid reuptake. The possibility that PMN uptake of RU 64004 and other macrolides occurs through a carrier-mediated system was suggested by three key results. First, there existed a strong interindividual variability in uptake kinetics, suggesting variability in the numbers or activity of a transport protein. Second, macrolide uptake displayed saturation kinetics characteristic of that of a carrier-mediated transport system: RU 64004 had the highest Vmax value (3,846 ng/2.5 x 10(6) PMNs/5 min) and the lowest Km value (about 28 microM), indicating a high affinity for the transporter. Third, as observed previously with other erythromycin A derivatives, Ni2+ (a blocker of the Na+/Ca2+ exchanger which mediates Ca2+ influx in resting neutrophils) impaired RU 64004 uptake by PMNs, with a 50% inhibitory concentration of about 3.5 mM. In addition, we found that an active process is also involved in macrolide efflux, because verapamil significantly potentiated the release of all three macrolides tested. This effect of verapamil does not seem to be related to an inhibition of Ca2+ influx, because neither EGTA [ethylene glycol-bis (beta-aminoethyl ether)-N,N',N'-tetraacetic acid] nor Ni2+ modified macrolide efflux. The nature and characteristics of the entry- and efflux-mediating carrier systems are under investigation.     

The macrolide roxithromycin impairs NADPH oxidase activation and alters translocation of its cytosolic components to the neutrophil membrane in vitro

We have studied the interference of roxithromycin with NADPH oxidase, the key enzymatic system for oxidant production by human neutrophils. Roxithromycin alters the reconstitution of an active enzyme and impairs the translocation to the outer membrane of the cytosolic components p47-phox and p67-phox. Interestingly, in resting cells roxithromycin directly triggers the translocation of these factors without stimulating the oxidative burst.     

A simple and rapid approach for screening of SARS-coronavirus genotypes: an evaluation study

Background  

The Severe Acute Respiratory Syndrome (SARS) was a newly emerged infectious disease which caused a global epidemic in 2002–2003. Sequence analysis of SARS-coronavirus isolates revealed that specific genotypes predominated at different periods of the epidemic. This information can be used as a footprint for tracing the epidemiology of infections and monitor viral evolution. However, direct sequencing analysis of a large number of clinical samples is cumbersome and time consuming. We present here a simple and rapid assay for the screening of SARS-coronavirus genotypes based on the use of fluorogenic oligonucleotide probes for allelic discrimination.     

Pregnancy with concomitant chorangioma and placental vascular malformation with mesenchymal hyperplasia

We present two pregnancies associated with normal live births and the unusual concomitance of chorangioma and placental vascular malformation with mesenchymal hyperplasia. The enlarged placenta had the characteristic findings of chorangioma, dilated and varicose chorionic vessels and multiple vesicle-like villi containing hyaluronic acid. The vesicle-like villi showed diploid cellular DNA contents. Molecular genetic analysis using the polymerase chain reaction amplification of polymorphic microsatellite markers confirmed genetic identity among the chorangioma, the vesicle-like villi and the fetus. Both pregnancies were complicated by polyhydramnios, pre-term labour and prematurity. One neonate suffered from anaemia and thrombocytopenia. Another neonate suffered from haemangiomatosis. Our cases demonstrate that concomitant chorangioma and placental mesenchymal hyperplasia are genetically identical to the fetus and can coexist with a normal viable fetus. Since haemangiomas, chorangiomas, chorionic vessels and villi mesenchymal cells are all derived from the mesoderm, a combination of fetal haemangiomas, placental vascular malformation, chorangiomas and placental mesenchymal hyperplasia may represent a mixed form of congenital malformation of the mesoderm.      

Antibody cross-reactivity induced by the homologous regions in glutamic acid decarboxylase (GAD65) and 2C protein of coxsackievirus B4

GAD₆₅ contains an amino acid sequence which is highly homologous with a sequence in the 2C protein of coxsackievirus B4 (CBV4-2C). In the present study the possibility that this region could contain an epitope capable of inducing immunological cross-reactivity between CBV4-2C and GAD₆₅ was evaluated. Six out of seven rabbit sera, which were raised against seven different synthetic peptides carrying various modifications of the homology sequence, showed cross-reactivity between 2C, GAD₆₅ and GAD₆₇ derived peptides in ELISA. There was substantial cross-reactivity between 2C and GAD₆₅ peptides, but not between 2C and GAD₆₇ peptides. The most cross-reactive peptides were those corresponding to the 2C sequences FIEWLKVKILPEVKEK and KILPEVKEKHEFLSRL. When the binding of the four 2C peptide-specific sera to the GAD₆₅ protein was analysed in immunoprecipitation, two sera were found to be cross-reactive (anti-FIEWLKVKILPEVKEK and anti-WLKVKILPEVKEKHEF). One of these (anti-WLKVKILPEVKEKHEF) reacted also with coxsackie B virus (CBV)-infected cells. Antibodies against this epitope were induced during enterovirus (including CBV) infections in initially healthy children who later progressed to clinical insulin-dependent diabetes mellitus (IDDM). Antibody responses were frequent also in constantly GAD₆₅ antibody-negative non-diabetic children, and antibody levels did not differ between newly diagnosed IDDM patients and matched control subjects. Blocking experiments confirmed that the observed reactivity of both rabbit and human antibodies was immunologically specific. The results suggest that the epitope is antigenically highly similar in 2C and GAD₆₅, and that peptide immunization induces antibodies which cross-react with these molecules. However, the significance of this phenomenon in the pathogenesis of IDDM remains to be confirmed, as the peptide antibody levels were similar in patients with recent-onset IDDM and in control subjects.     

Subsequent reproduction and obstetric outcome after methotrexate treatment of cervical pregnancy: a review of original literature and international collaborative follow-up

The case reports of 22 patients with cervical pregnancies treated by methotrexate (MTX) administration and published in English literature between 1983 and 1995 were reviewed, by either original paper review or follow-up under international collaboration, to determine the subsequent reproductive performance and obstetric outcomes. Out of 22 cases, 18 (78%) MTX chemotherapy attempts succeeded with complete remission and four (22%) failed. Of the 13 women who wished to conceive and could be followed for at least 3 years, nine succeeded in having live births without congenital malformations, one spontaneously aborted and three suffered infertility. In general, MTX chemotherapy alone or combined with adjuvant methods such as subsequent cervical curettage or cervical tamponade, or intracervical potassium chloride injection, appears to be a convenient and effective method for the treatment of the majority of cervical pregnancies before 12 weeks gestation, and has not been shown to have detrimental effects on subsequent reproductive capacities, obstetric outcomes and progeny health for those cases with successful preservation of the uteri.      

Common Peptide Epitope in Mumps Virus Nucleocapsid Protein and MHC Class II-Associated Invariant Chain

The present study describes a 7 amino acid-long sequence (YQQQGRL) which is identical in HLA-associated invariant chain and mumps virus nucleocapsid protein and is additionally followed by one conservative amino acid pair. As such a long amino acid homology is extremely rare in two evolutionarily unrelated proteins the possibility that it could induce immunological cross-reactivity was evaluated. Several antigenicity indices suggested high antigenic potential within this region. Synthetic peptides containing this sequence were reactive with 31% of monoclonal antibodies specific for mumps virus nucleocapsid protein in ELISA. High antibody levels against this epitope were found in 7% of mumps-seropositive human sera and antibody levels clearly increased after natural mumps infections and mumps vaccinations. Rabbit antibodies raised against a synthetic invariant chain peptide AYF-LYQQQGRLDKL-C reacted with corresponding nucleocapsid peptide RFAKYQQQGRLEAR-C and antibodies against the nucleocapsid peptide reacted with the invariant chain peptide. Rabbit antibodies against the invariant chain peptide also reacted with nucleocapsid molecules in formaldehyde-fixed mumps virus-infected cells, and antibodies against the nucleocapsid peptide reacted with invarianl chains expressed in methanol-fixed cells. One monoclonal antibody specific for the nucleocapsid molecule also reacted with cells expressing invariant chains. In immunoprecipitation rabbit antibodies against the invariant chain peptide bound to invariant chains while antibodies against the nucleocapsid peptide did not. The results suggest tha t there is antigenic similarity in mumps virus nucleocapsid molecule and HLA-associated invariant chain which may cause immunological cross-reactivity between these molecules.