Human semen study around and away from gold mine area.

Gold was first detected in human semen in 1981. The entry of gold into semen was hypothesized through food items. Earlier reports identified gold in semen as important for good quality of semen. The infertility rate could be low around gold mine area when compared to other places. The aim of the study was to verify this. Towards this, the quality of human semen around a gold mine (Kolar, India) was evaluated and compared to that from a place which was 2000 km away from a gold mine (Jamnagar, India). A total number of 254 semen samples from Kolar and 437 from Jamnagar were evaluated. The fertility rate was higher in Kolar region. The semen samples studied for both places showed that the semen quality was superior in Kolar gold field area.

A molecular comparison of T lymphocyte populations infiltrating the liver and circulating in the blood of patients with chronic hepatitis B: evidence for antigen-driven selection of a public complementarity-determining region 3 (CDR3) motif.

Despite a large number of T cells infiltrating the liver of patients with chronic hepatitis B, little is known about their complexity or specificity. To characterize the composition of these T cells involved with the pathogenesis of chronic hepatitis B (CHB), we have studied the clonality of VbetaT cell receptor (TCR)-bearing populations in liver tissue by size spectratyping the complementarity-determining region (CDR3) lengths of TCR transcripts. We have also compared the CDR3 profiles of the lymphocytes infiltrating the liver with those circulating in the blood to see whether identical clonotypes may be detected that would indicate a virus-induced expansion in both compartments. Our studies show that in most of the patients examined, the T cell composition of liver infiltrating lymphocytes is highly restricted, with evidence of clonotypic expansions in 4 to 9 TCR Vbeta subfamilies. In contrast, the blood compartment contains an average of 1 to 3 expansions. This pattern is seen irrespective of the patient's viral load or degree of liver pathology. Although the TCR repertoire profiles between the 2 compartments are generally distinct, there is evidence of some T cell subsets being equally distributed between the blood and the liver. Finally, we provide evidence for a putative public binding motif within the CDR3 region with the sequence G-X-S, which may be involved with hepatitis B virus recognition.

A longitudinal analysis of cytotoxic T lymphocyte precursor frequencies to the hepatitis B virus in chronically infected patients.

Individuals with acute hepatitis B virus (HBV) infection characteristically mount a strong, multispecific cytotoxic T lymphocyte (CTL) response that is effective in eradicating virus. In contrast, this response in chronic carriers is usually weak or undetectable. Since it is generally acknowledged that HBV pathogenesis is immune-mediated, the occurrence of episodes of active liver disease in many carriers suggests that these individuals can mount active CTL responses to HBV. To see whether the detection of circulating CTLs is related to these flare episodes, we have determined the CTL precursor (CTLp) frequencies to HLA-A2-restricted viral peptides in seven patients over a 12-24-month period of their disease. Limiting dilution analyses (LDA) were performed longitudinally to five epitopes comprising the viral capsid (HBc), envelope (HBs) and polymerase (pol) proteins. Assays were performed against a mixture of peptides, or against each individual peptide, to measure overall CTL activity and the multispecificity of the responses, respectively. Since two of the patients were treated with recombinant human interleukin-12 (rHuIL-12) at the time, with one individual achieving complete disease remission a year later after being treated with interferon-alpha, we were also able to examine the effects of these cytokines on HBV cytotoxicity. Our results indicate that weak but detectable CTL responses do occur in chronic carriers which are generally associated with disease flares, although CTLps were also seen occasionally during minimal disease activity. The range of specificities varied between individuals and within each individual during the course of the disease. Finally, we also provide evidence that CTL reactivity is stimulated following treatment with certain cytokines, but is dependent on the time of administration.

Rehabilitation of the disabled in Hong Kong.

This paper examines the early history of the Hong Kong government's approach to rehabilitation services. The fundamental purpose of the programme was prevention founded on the premise that, by reducing the incidence of disability, the need for rehabilitation services would be reduced.

Distinct patterns of T cell receptor distribution of peripheral blood CD8+ cells during different stages of chronic infection with hepatitis B virus.

We compared the Vbeta TCR repertoires of CD8+ peripheral blood lymphocytes between 21 patients with chronic hepatitis B (CHB) and 9 healthy individuals, using RT-PCR analysis. Several differences were seen between CHB patients and controls, including a marked increase in the expression of two to five Vbeta families in the CHB patients. There was no evidence for a superantigen effect, although an increase in Vbeta7 was seen in 64% of patients. A significant under-expression of Vbeta families were also detected, particularly in patients with active liver disease in which under-expression of Vbeta14 and Vbeta15 was associated with acute exacerbations of liver disease. We also did a longitudinal analysis of the TCR repertoire in two patients over a period of 6 months, from the initiation of a disease flare to its resolution. One patient continued to experience spontaneous flares following the completion of this study, while the other patient underwent spontaneous remission with long-term (> 12 months) loss of HBeAg following resolution of the flare. The TCR repertoires of both patients were altered during the flare, and there was a higher degree of TCR variability in the patient who went into remission.

Composition of peripheral blood lymphocyte populations during different stages of chronic infection with hepatitis B virus.

To characterize the immunological populations associated with different stages of chronic infection with hepatitis B virus (HBV), we performed flow cytometric analyses on the peripheral blood leucocytes of 29 patients with various forms of chronic hepatitis B. The clinical spectrum of the patients ranged from asymptomatic infections, in the presence of high virus production, to intermittent or recurrent exacerbations of liver injury alternating with relatively normal liver function. Patients with partial resolution of disease who experienced an initial acute flare followed by prolonged seroconversion showed decreased percentages of CD3+ cells during the seroconversion phase when levels of serum alanine transferase (ALT) had normalized. These CD3+ cells were predominantly CD4+ cells bearing the alpha beta+ T-cell receptor (TCR). In addition, we saw an increase in CD4+ and CD8+ cells bearing the gamma delta TCR in those patients who had seroconverted. No significant differences were seen between any of the groups with respect to percentage of cells with a naive (CD45RA) or memory (CD45RO) phenotype, or of cells displaying the activation markers CD38, HLA-DR or CD57. Longitudinal analyses of 15 patients failed to show any consistent pattern of changes in the immunophenotypic profile during acute flares and their resolution. Our results indicate that the turnover of circulating T lymphocytes during the apparent quiescent phase of chronic infections is higher than that during acute exacerbations, suggesting an active immunosurveillance role of T-cell subpopulations in maintaining low virus levels during seroconversion.

Anti-IgM induces transforming growth factor-beta sensitivity in a human B-lymphoma cell line: inhibition of growth is associated with a downregulation of mutant p53.

We wished to examine the role of transforming growth factor-beta (TGF-beta) in the regulation of human lymphoma cell growth. The RL cell line is an immunoglobulin M (IgM)+, IgD+ B lymphoma cell line, which does not constitutively express receptors for TGF-beta, and thus has lost the ability to respond to the inhibitory effects of TGF-beta. We demonstrate here that anti-Ig antibodies can efficiently upregulate the expression of TGF-beta receptors and promote sensitivity to growth inhibition by TGF-beta. Furthermore, because TGF-beta has been shown to function in late G1 of the cell cycle, we examined the ability of TGF-beta to modulate two tumor suppressor proteins known to be critical regulators of the G1/S transition, Rb and p53. Rb is a 105- to 110-kD phosphoprotein, which has been shown to maintain its growth suppressive function when it is found in the hypophosphorylated state. Wild-type p53 is a 53-kD phosphoprotein that appears to be important in preventing cell-cycle progression and promoting apoptosis in cells with DNA damage, whereas mutant p53 can overcome those functions. We show here that TGF-beta treatment of phorbol myristate acetate (PMA) or anti-Ig-activated RL cells results in growth inhibition through a dual effect on Rb and mutant p53. After TGF-beta treatment, we observe a predominance of Rb in the hypophosphorylated, growth suppressive form. In addition, we show a decrease in levels of mRNA and protein for mutant p53. We also show that, although these changes are sufficient to halt progression through the cell cycle, the cells do not appear to undergo extensive programmed cell death following 72 hours of TGF-beta treatment. Thus, although these lymphoma cells maintain the capacity to be negatively growth regulated by TGF-beta, the ability of TGF-beta to induce apoptosis must be independently controlled.

The role of human cytomegalovirus in haematological diseases.

Infection with HCMV in healthy individuals generally results in mild or subclinical illness. Pathogenic infections occur predominantly in immunodeficient patients, such as transplant recipients, neonates and patients with AIDS. Primary infection is frequently latent or chronic and PBLs represent sites for virus latency and persistence. HCMV can be recovered from PMNL, monocytes and T-lymphocytes. Although virus-related cases of haematopoietic dysfunction are seen infrequently in infected normal persons, the importance of HCMV as a pathogenic agent in haematopoiesis is dramatically illustrated in the case of patients receiving BMT. Primary or reactivated HCMV infections are a common feature in BMT recipients, enhancing failure of marrow engraftment, GVHD, and many opportunistic infections. HCMV can infect both haematopoietic progenitor cells and stromal elements, identifying the entire haematopoietic system as a target for HCMV dissemination and latency. As a result, lympho- and myelosuppression can be due to both direct inhibition of progenitor cell growth as well as the failure of stem cell self-renewal due to stromal cell dysfunction. HCMV can also exert suppressive effects on immune cell function by direct and indirect mechanisms. These effects can have dire consequences, particularly when a state of immunosuppression already exists, as in the HIV infection. The diverse effects of CMV on the lymphohaematopoietic system are summarized in Figure 1.

Establishment of a cell line from a hepatocellular carcinoma from a patient with hemochromatosis.

We describe the establishment and characterization of a novel hepatoma cell line. This cell line, designated RBHF-1, was established from a hepatocellular carcinoma of a 67-yr-old man with a history of genetic hemochromatosis. At this writing, the cells have been maintained in RPMI-1640 tissue-culture medium and fetal calf serum without any additional supplements for 30 mo. The cells form colonies on soft agar and are not tumorigenic in nude mice. The cell line is polymorphic and displays characteristics of mature hepatocytes by synthesizing albumin, alpha 2-macroglobulin, fibronectin and alpha-fetoprotein. Cytogenetic analysis shows multiple chromosomal aberrations, with a consistent deletion in the long arm and deletions or rearrangements in the short arm of chromosome 1. There is no evidence for hepatitis B or hepatitis C virus infection of the cell line. The cells contain no detectable intracellular iron after staining with Perls' stain. Unlike other hepatoma cell lines, there is no detectable binding of epidermal growth factor to RBHF-1 cells. This is the first cell line to be established from a patient with hemochromatosis, and it provides a potentially important model for the study of hepatocyte transformation in association with iron overload.

Infection of human bone marrow stromal cells by hepatitis B virus: implications for viral persistence and the suppression of hematopoiesis.

Suspension cultures of bone marrow cells (BMC) were challenged with hepatitis B virus (HBV) to study interactions between the virus and the nonadherent and adherent BMC populations. Virus-challenged BMC developed an adherent stromal layer that differed in cellular composition from that of mock-infected cultures, showing a threefold increase in cells of the monocyte-macrophage lineage with an accompanying decrease in cells of the granulocytic lineage. Both viral envelope hepatitis B surface and core antigen expression was detected in adherent and nonadherent cell populations up to 10 days after virus challenge, which decreased thereafter. HBV DNA was still detectable in adherent cells 3 weeks after virus challenge, as shown by polymerase chain reaction analysis. These data indicate that HBV can infect not only bone marrow colony-forming cells but also the stromal cell populations involved with the regulation of hematopoiesis in vivo. Such virus-cell interactions could contribute to the immune dysfunction and bone marrow failure occasionally reported for patients with HBV infection as well as acting as an important site for HBV latency and persistence.

Hepatitis B virus differentially suppresses myelopoiesis and displays tropism for immature hematopoietic cells.

The hematopoietic cell lines HL-60 and THP-1 were challenged with hepatitis B virus (HBV) in vitro to study interactions between the virus and host cell. Exposure to HBV suppressed the ability of HL-60 cells to differentiate into granulocytes after treatment with retinoic acid (RA) or dimethyl sulfoxide (DMSO), and RA-induced activation of the monocytic cell line THP-1 was also suppressed. Terminal differentiation of both cell lines by phorbol 12-myristate 13-acetate (PMA) was not affected by HBV. The suppressive effect on RA- or DMSO-induced differentiation was unique to HBV, since cell exposure to human cytomegalovirus, another virus that inhibits hematopoiesis, failed to block cellular differentiation. At 5 days postinfection, extracellular viral DNA was detected in immature but not in differentiated cultures and higher levels of core antigen (HBcAg) and surface antigen (HBsAg) were seen in undifferentiated cells than in RA- or PMA-treated cells. In addition, release of HBsAg into the medium was 2 to 12 times greater in untreated cultures than for RA- or PMA-treated cells. Thus, HBV suppresses hematopoiesis by blocking the maturational development of progenitors and selectively infects immature myeloid cells compared with mature end-stage cells.

In vivo and in vitro effects of TGF-beta 1 on normal and neoplastic haemopoiesis.

TGF-beta 1 and TGF-beta 2 are equipotent selective inhibitors of murine and human haemopoiesis in vitro. Primitive haemopoietic cells such as the high proliferative potential progenitor cell and the colony-forming unit (CFU)-GEMM are directly inhibited by TGF-beta whereas the more differentiated CFU-G, CFU-M and CFU-E are not. Recombinant TGF-beta 1 administered intraperitoneally or intravenously to mice selectively inhibits haemopoietic colony formation in a time- and dose-dependent manner to the same extent as seen in vitro. The progenitors are reversibly prevented from entering the cell cycle. This inhibitory action of TGF-beta functions on at least two levels: (1) down-modulation of the cell surface expression of receptors for growth stimulatory molecules and (2) interference with the intracellular signalling pathways of these molecules. In addition, expression of TGF-beta receptors is regulated during cytokine stimulation of haemopoiesis. Neoplastic B lymphocytes can proliferate by escaping from a TGF-beta-mediated autocrine inhibitory loop. Activation signals (e.g. phorbol esters) inhibit tumour cell growth by stimulating active TGF-beta production and inducing cell surface expression of TGF-beta receptors. These results indicate that TGF-beta may be useful as a bone marrow protective and/or an antitumour agent.

Growth inhibition of a human lymphoma cell line: induction of a transforming growth factor-beta-mediated autocrine negative loop by phorbol myristate acetate.

Transforming growth factor-beta (TGF-beta) exerts profound inhibitory effects on a number of cell types, including normal B- and T-lymphocytes. In contrast, we have found a number of lymphoid tumor cell lines to be insensitive to the antiproliferative effects of TGF-beta 1 or TGF-beta 2. Binding and cross-linking with radioiodinated TGF-beta 1 demonstrated either low or absent expression of all three TGF-beta receptor species on three B-cell tumor lines, but T-cell and non-T, non-B tumors expressed large numbers of receptors. Treatment of the B-cell lines with phorbol 12-myristate 13-acetate (PMA) induced the expression of TGF-beta receptors and inhibited proliferation in all three lines in a dose- and time-dependent manner. The cell lines constitutively produced TGF-beta mRNA and released small amounts of latent TGF-beta; however, PMA induced the release of active TGF-beta. A neutralizing antibody to TGF-beta was able to reverse the PMA-induced growth inhibition of the malignant lymphoma cell line, RL, and addition of exogenous TGF-beta reversed the effect of the neutralizing antibody. Thus, TGF-beta can inhibit human lymphoma cell growth in vitro through an autocrine mechanism. Some lymphoma cells appear to have escaped from TGF-beta negative regulation by failing to express functional TGF-beta receptors and/or by failing to secrete active TGF-beta receptors and/or by failing to acts to inhibit lymphoma cell growth is by inducing the expression of TGF-beta receptors and the secretion of active TGF-beta, thereby reestablishing an autocrine growth-inhibitory loop.

Preferential suppression of myelopoiesis in normal human bone marrow cells after in vitro challenge with human cytomegalovirus.

The pathogenic effects of human cytomegalovirus (CMV) infection in vitro on hematopoiesis were investigated. Normal human bone marrow cells from both seronegative and seropositive donors were challenged with CMV (Towne or wild-type strain) and tested for their responsiveness to the recombinant hematopoietic growth factors granulocyte-macrophage colony-stimulating factor (GM-CSF) and granulocyte-CSF (G-CSF), respectively. Regardless of the serostatus of the donor, infection with CMV resulted in a significant decrease in the proliferation and colony formation of hematopoietic progenitor cells in response to both growth factors, with more pronounced suppression in response to G-CSF being observed. Evaluation of the colony composition revealed a profound decrease in colonies of the granulocytic (CFU-G), or granulocyte-macrophage (CFU-GM) lineages, while suppression of multipotential (CFU-GEMM) and erythroid (BFU-E) colony-forming cells occurred after infection with wild-type but not the laboratory strain of CMV. Although no evidence of productive virus infection could be seen in colony-forming cells, in situ hybridization studies and immunohistochemical staining revealed the presence of CMV-specific mRNA and immediate-early antigens, demonstrating that a small proportion of cells were abortively infected. These studies demonstrate that CMV can infect bone marrow progenitor cells and interfere with normal hematopoiesis in vitro, which may help to explain the hematologic defects seen during acute infections with CMV in vivo.

Transforming growth factor beta directly regulates primitive murine hematopoietic cell proliferation.

We previously reported that transforming growth factor beta (TGF-beta) selectively inhibits colony-stimulating factor-driven hematopoietic progenitor cell growth. We report here that TGF-beta 1 can act directly on hematopoietic progenitors to inhibit the growth of the most primitive progenitors measurable in vitro. Highly enriched populations of hematopoietic progenitor cells were obtained by isolating lineage negative (Lin-), Thy-1-positive (Thy-1+) fresh bone marrow cells, or by isolating cells from interleukin-3 (IL-3) supplemented bone marrow cultures expressing Thy-1 antigen with the fluorescent activated cell sorter. TGF-beta 1 inhibited IL-3-induced Thy-1 expression on Thy-1-negative (Thy-1-) bone marrow cells in a dose-dependent manner with an ED50 of 5 to 10 pmol/L. In addition, TGF-beta 1 inhibited the formation of multipotent and mixed colonies by isolated Thy-1+ cells, while single lineage granulocyte and macrophage colonies were not affected. The growth of Thy-1+ Lin- cells incubated as single cells in Terasaki plates in medium supplemented with IL-3 were inhibited by TGF-beta, demonstrating a direct inhibitory effect. Hematopoietic stem cells, which have a high proliferative potential (HPP) when responding to combinations of growth factors in vitro, have been detected in the bone marrow of normal mice and mice surviving a single injection of 5-fluorouracil. TGF-beta 1 inhibited the growth of all subpopulations of HPP colony forming cells (CFC) in a dose-dependent manner with an ED50 of 5 to 10 pmol/L. Thus, TGF-beta directly inhibits the growth of the most immature hematopoietic cells measurable in vitro.