High prevalence of hepatitis B virus pre-s mutant in countries where it is endemic and its relationship with genotype and chronicity

It has been reported that hepatitis B virus (HBV) mutants carrying mutations in the pre-S region can be found in infected patients. In this study, we investigated the prevalence of the HBV variant with the pre-S mutant in different geographic regions, including countries with low and high levels of endemic HBV infection, and analyzed the correlation with clinical findings. We examined 387 HBV DNA-positive serum samples from individuals among 12 countries, consisting of Vietnam, Myanmar, Thailand, China, Korea, Nepal, Japan, Russia, Spain, United States, Bolivia, and Ghana. HBV pre-S mutants were detected in 71 (18.3%) of 387 serum samples tested. This mutant was the most prevalent in Vietnam (36%), followed by Nepal (27.3%), Myanmar (23.3%), China (22.4%), Korea (14.3%), Thailand (10.5%), Japan (7.7%), and Ghana (4.3%). In contrast, no case with this mutation was found in Russia, Spain, United States, and Bolivia. Among the HBV deletion mutations, 15.5% (11 of 71) occurred in the pre-S1 and 46.5% (33 of 71) in the pre-S2 regions. Eight (11.3%) cases had a mutation in both the pre-S1 and pre-S2 regions. In addition, a point mutation at the pre-S2 starting codon was observed in 19 (26.7%) cases. The detection rate of the HBV mutant in patients with hepatocellular carcinoma was significantly higher than in other patients (P < 0.05). Furthermore, these mutants were found more frequently in genotype B (25%) and genotype C (24.5%) than in the other genotypes (P < 0.05). Our results indicated that there was a high prevalence of HBV pre-S mutation in regions of endemic HBV infection in Asia. Furthermore, the pre-S mutation appeared to be correlated with hepatocellular carcinoma and HBV genotypes.     

Diversity of genomic breakpoints in TFG-ALK translocations in anaplastic large cell lymphomas: identification of a new TFG-ALK(XL) chimeric gene with transforming activity

Anaplastic large cell lymphomas are associated with chromosomal aberrations involving the anaplastic lymphoma kinase (ALK) gene at 2p23 that result in the expression of novel chimeric ALK proteins with transforming properties. In most of these tumors, the t(2;5)(p23;q35) generates the NPM-ALK fusion gene. However, several studies have now demonstrated that genes other than NPM may be fused to the ALK gene. We have recently described two different ALK rearrangements involving the TRK-fused gene (TFG) in which the same portion of ALK was fused to different length fragments of the 5' TFG region. These two rearrangements encoded chimeric proteins of 85 kd (TFG-ALK(S)) and 97 kd (TFG-ALK(L)), respectively. In this study, we have identified a new ALK rearrangement in which the catalytic domain of ALK was fused to a larger fragment of the TFG gene (TFG-ALK(XL)), encoding for a fusion protein of 113 kd. Genomic analysis of these three TFG-ALK rearrangements revealed that the TFG breakpoints occur at introns 3, 4, and 5, respectively, whereas the ALK breakpoints always occur in the same intron. No homologous regions or known recombination sequences were found in these regions. Transfection experiments using NIH-3T3 fibroblasts showed a similar transforming efficiency of TFG-ALK variants compared with NPM-ALK. In addition, in common with NPM-ALK, the TFG-ALK proteins formed stable complexes with the signaling proteins Grb2, Shc, and PLC-gamma. In conclusion, these findings indicate that the TFG may use a variety of intronic breakpoints in ALK rearrangements generating fusion proteins of different molecular weights, but with similar transforming potential than NPM-ALK.     

Antibodies to PAI-1 alter the invasive and migratory properties of human tumour cells in vitro

Recent reports suggest that elevated levels of plasminogen activator inhibitor-1 (PAI-1) may contribute to tumour progression. The studies reported here were designed to help elucidate PAI-1's contribution to the invasive and migratory phenotype. Antibodies to PAI-1 dose-dependently, and significantly, inhibited the invasive and migratory potential of human HT1080 fibrosarcoma cells, as did an antibody to uPA and the plasmin inhibitor aprotinin. Invasion of the human melanoma cell line, BLM, was also attenuated by the anti-PAI-1 monoclonal antibody MAI-12. The non-invasive human melanoma cell line, IF6, which does not express uPA, provided further confirmation of PAI-1 and uPA's role as, upon transfection with uPA, this cell line attained an invasive phenotype, which was again attenuated by MAI- 12. Although antibodies to PAI-1 did not affect the adhesion of HT1080 cells to vitronectin, the antibody to uPA reduced their attachment. Addition of exogenous PAI-1, however, prevented HT1080 cell adhesion (IC₅₀ 180nM) and promoted cell detachment from vitronectin. Furthermore melanoma cells transfected with a uPA variant, which had an impaired interaction with PAI-1, were not invasive and had impaired binding to vitronectin. These data highlight the importance of a balanced proteolysis and suggest an additional role for PAI-1 distinct from its role in proteolysis. These data also suggest that uPA and PAI-1 may co-operate in the migratory process by respectively facilitating the attachment to, and subsequent detachment from, vitronectin in the extracellular matrix. These results support the clinical findings and indicate that modulation of PAI-1 activity may be of therapeutic benefit for the treatment of cancer. This revised version was published online in July 2006 with corrections to the Cover Date.     

Morphometric analysis of the pineal complex of the golden hamster over a 24-hour light: Dark cycle: I. The superficial pineal in untreated and optically enucleated animals

Morphometric analysis of the superficial pineal gland of intact and blinded golden hamsters was conducted at both the light and electron microscopic level. The volume of the superficial gland was estimated to be 151 × 10⁶ μm³, comprising 90–94% of the total pineal parenchymal tissue. Analysis of structural rhythms in animals maintained under a 14:10 L:D cycle showed significant 24-hr variations in values for pinealocyte nuclei, nucleoli, rough and smooth endoplasmic reticulum, Golgi bodies, dense bodies, and dense-cored vesicles. Peak values for these structures generally occurred at the light:dark interface. These results provide morphological correlates for known rhythmic variations in the synthesis of pineal-gland products. Superficial pineals examined 8 weeks following optic enucleation exhibited a decrease in the volume of pinealocyte nuclei and cytoplasm, while nucleolar size and the amounts of smooth and rough endoplasmic reticulum, Golgi bodies, dense bodies and dense-cored vesicles were enhanced. The latter changes are interpreted as indications of increased synthetic activity by the superficial pineal gland in response to light deprivation.     

Proliferation in HHV-8-positive primary effusion lymphomas is associated with expression of HHV-8 cyclin but independent of p27(kip1)

Primary effusion lymphoma (PEL) develops in immunodeficient patients, selectively localizes to the serous body cavities, and harbors infection by human herpesvirus type-8 (HHV-8), also known as Kaposi's sarcoma-associated herpesvirus. HHV-8 encodes a viral (v)-cyclin homologous to cellular D-type cyclins, a class of positive cell-cycle regulators that are physiologically modulated by the p27(Kip1) cell cycle inhibitor. The aims of the present study were: 1) to establish the expression pattern of p27(Kip1) in PEL; and 2) to address the relationship between p27(Kip1) expression, proliferation index, and expression of cellular cyclin D1 and v-cyclin in PEL. Expression of p27(Kip1) was detected in all (n = 18) PEL samples analyzed by both immunocytochemistry and Western blot. All PELs displayed a high proliferation index as assessed by Ki-67 staining. Expression of cellular cyclin D1 was absent in all PELs tested, which conversely expressed (14 out of 14 samples) v-cyclin by immunocytochemistry and/or Western blot. In contrast to PELs, HHV-8-negative lymphomatous effusions secondary to a tissue-based lymphoma generally failed to express p27(Kip1). Overall, these data show that PELs consistently express p27(Kip1) protein despite the high proliferative rate of the lymphoma clone, suggesting that p27(Kip1) may be unable to drive cell-cycle arrest in PEL cells. The co-existence of p27(Kip1) expression and high proliferative index is a selective feature of PEL among lymphomas involving the serous body cavities, because lymphomatous effusions secondary to a tissue-based lymphoma generally display the inverse relationship between p27(Kip1) positivity and growth fraction observed in normal lymphoid tissues and in most other lymphomas. Expression of p27(Kip1) in PEL associates with expression of HHV-8 v-cyclin, but not of cellular cyclin D1. The fact that HHV-8 v-cyclin is resistant to p27(Kip1)-modulated inhibition, whereas cellular cyclin D1 is sensitive, may explain, at least in part, the co-existence of p27(Kip1) expression and high proliferative index observed in PEL.     

Deletion spanning the 5′ ends of both the COL4A5 and COL4A6 genes in a patient with Alport's syndrome and leiomyomatosis

Alport's syndrome is characterized clinically by a nonimmune glomerulopathy, often accompanied by sensorineural hearing loss and lens abnormalities, frequently due to mutations in the COL4A5 gene. The association of AS with diffuse leiomyomatosis, a benign proliferation of smooth muscle that occurs most often in the esophagus, trachea, and female genitalia, has been reported. Recently, a deletion involving both the COL4A5 and COL4A6 genes has been reported in four unrelated families. We report an additional case with Alport's syndrome associated with leiomyomatosis carrying a deletion of both COL4A5 and COL4A6 genes. A detailed characterization of the genomic region involved in the deletion event has been performed. Our results demonstrate that the deletion removed exon l of COL4A5 and exons l and 2 of COL4A6. © 1994 Wiley-Liss, Inc.     

Co-expression of Epstein-Barr virus latent membrane protein and vimentin in “aggressive” histological subtypes of Hodgkin's disease

Summary The presence of Epstein-Barr virus (EBV) genome in Hodgkin's and Reed-Sternberg (HRS) cells, as detected using in situ hybridization (ISH) with biotinylatedBamHI V probes, along with the expression of EBV-encoded latent membrane protein (LMP) and vimentin was examined in paraffin-embedded sections of 39 immunomorphologically characterized cases of Hodgkin's disease (HD). ISH demonstrated EBV in HRS cells in 15 of 39 cases, whereas LMP expression was detected in 11 of 39 cases, only in the presence of EBV genome detection. With the exception of 1 case, in which HRS cells expressed B-cell-associated antigens, the LMP-positive cases included specimens in which HRS cells were of non-B, non-T phenotype. LMP expression showed a stronger association with lymphocyte depletion (LD) (3/3) and mixed cellularity (MC) (6/11) than with lymphocyte predominance (0/5) or nodular sclerosis (2/20) subtypes. Vimentin expression on HRS cells was found in all the LMP-expressing cases and only in a fraction (13/28) of LMP-negative cases. This study supports the view that HD represents a heterogeneous group of diseases also in terms of EBV association, LMP expression being strongly related to the aggressive LD and MC histological subtypes. In light of the supposed interactions between vimentin and LMP, their coexpression on HRS cells, as detected in this study, provides further evidence for a significant role of EBV in the development of a proportion of HD cases.     

Long-chain omega-3 fatty acids regulate bovine whole-body protein metabolism by promoting muscle insulin signalling to the Akt–mTOR–S6K1 pathway and insulin sensitivity

The ability of the skeletal musculature to use amino acids to build or renew constitutive proteins is gradually lost with age and this is partly due to a decline in skeletal muscle insulin sensitivity. Since long-chain omega-3 polyunsaturated fatty acids (LC n –3PUFA) from fish oil are known to improve insulin-mediated glucose metabolism in insulin-resistant states, their potential role in regulating insulin-mediated protein metabolism was investigated in this study. Experimental data are based on a switchback design composed of three 5 week experimental periods using six growing steers to compare the effect of a continuous abomasal infusion of LC n –3PUFA-rich menhaden oil with an iso-energetic control oil mixture. Clamp and insulin signalling observations were combined with additional data from a second cohort of six steers. We found that enteral LC n –3PUFA potentiate insulin action by increasing the insulin-stimulated whole-body disposal of amino acids from 152 to 308 μmol kg⁻¹ h⁻¹ ( P = 0.006). The study further showed that in the fed steady-state, chronic adaptation to LC n –3PUFA induces greater activation ( P < 0.05) of the Akt–mTOR–S6K1 signalling pathway. Simultaneously, whole-body total flux of phenylalanine was reduced from 87 to 67 μmol kg⁻¹ h⁻¹ ( P = 0.04) and oxidative metabolism was decreased ( P = 0.05). We conclude that chronic feeding of menhaden oil provides a novel nutritional mean to enhance insulin-sensitive aspects of protein metabolism.     

Differences in virulence factors among clinical isolates of Escherichia coli causing cystitis and pyelonephritis in women and prostatitis in men

Differences in the presence of nine urovirulence factors among clinical isolates of Escherichia coli causing cystitis and pyelonephritis in women and prostatitis in men have been studied. Hemolysin and necrotizing factor type 1 occur significantly more frequently among isolates causing prostatitis than among those causing cystitis (P < 0.0001) or pyelonephritis (P < 0.005). Moreover, the papGIII gene occurred more frequently in E. coli isolates associated with prostatitis (27%) than in those associated with pyelonephritis (9%) (P < 0.05). Genes encoding aerobactin and PapC occurred significantly less frequently in isolates causing cystitis than in those causing prostatitis (P < 0.01 and P < 0.0001, respectively) and pyelonephritis (P < 0.01 and P < 0.0001, respectively). No differences in the presence of Sat or type 1 fimbriae were found. Finally, AAFII and Bfp fimbriae are no longer considered uropathogenic virulence factors since they were not found in any of the strains analyzed. Overall, the results showed that clinical isolates producing prostatitis need greater virulence than isolates producing pyelonephritis in women or, in particular, cystitis in women (P < 0.05). Overall, the results suggest that clinical isolates producing prostatitis are more virulent that those producing pyelonephritis or cystitis in women.