Use of hormone replacement therapy (Hrt) And detection of human papillomavirus (Hpv) Dna in postmenopausal women.

PURPOSE: This study investigated the association between detection of HPV DNA among current and past HRT users compared to never HRT users, duration of HRT use, and type of HRT (estrogen, estrogen/progestin).METHODS: Postmenopausal women (n = 390) were recruited from a university hospital and completed a questionnaire regarding 1) HRT use, duration, and type, 2) reproductive and sexual history, 3) smoking and alcohol use, and 4) HPV-related diseases. Cervical specimens were obtained for Pap smears, and for the presence of HPV using PCR/dot blot and DNA sequencing, and Southern blot or SSCP. Age-adjusted odds ratios (OR), 95% confidence intervals (CI), and logistic regression examined the association between HRT use and risk of HPV detection.RESULTS: The frequency of HPV was 10%, with 2.8% oncogenic types. Compared to Never Users, Current (adj. OR = 1.50, 95% CI = 0.55, 4.07) and Past (OR = 1.96, CI = 0.56, 6.86) HRT users had an elevated risk of HPV detection. Although HRT duration among Current Users was not statistically significant (OR = 1.01, 95% CI = 0.95, 1.07), duration among Past Users was significantly associated with an increased risk of HPV detection (OR = 1.30, CI = 1.06, 1.61). In addition, Past Users of estrogen/cyclic progestin HRT regimens were significantly more likely to be detected with HPV (OR = 1.82, CI = 1.11, 2.97) compared to Never Users.CONCLUSIONS: These findings indicate that risk of HPV detection is increased among users of HRTs, particularly among Past Users associated with longer duration and among those taking HRT regimens that included a progestin. Results suggest a latency or duration effect may be important in elevating the risk. They also support previous in vitro studies of progestin effects on HPV gene regulation.

Macrophage colony-stimulating factor antagonists inhibit replication of HIV-1 in human macrophages.

Macrophages infected with HIV-1 produce high levels of M-CSF and macrophage-inflammatory protein-1alpha (MIP-1alpha). M-CSF facilitates the growth and differentiation of macrophages, while the chemotactic properties of MIP-1alpha attract both T lymphocytes and macrophages to the site of HIV infection. Studies described in this work indicate M-CSF may function in an autocrine/paracrine manner to sustain HIV replication, and data suggest possible therapeutic strategies for decreasing viral load following HIV infection. We show that macrophage infection with measles virus or respiratory syncytial virus, in contrast to HIV-1, results in production of MIP-1alpha, but not M-CSF. Thus, M-CSF appears to be specifically produced upon infection of macrophages with HIV-1. Furthermore, addition of M-CSF antagonists to HIV-1-infected macrophages, including anti-M-CSF monoclonal or polyclonal Abs or soluble M-CSF receptors, dramatically inhibited HIV-1 replication and reduced production of MIP-1alpha. Our results suggest that biologic antagonists for M-CSF may represent novel strategies for inhibiting the spread of HIV-1 by 1) blocking virus replication in macrophages, 2) reducing recruitment of HIV-susceptible T cells and macrophages by MIP-1alpha, and 3) preventing the establishment and maintenance of infected macrophages as a reservoir for HIV.

Human astrocytes inhibit HIV-1 expression in monocyte-derived macrophages by secreted factors.

OBJECTIVE: To determine the effects of primary human fetal and adult astrocytes on HIV-1 replication in monocyte-derived macrophages (MDM). DESIGN: HIV-1 can infect the brain in the early stage of systemic infection. The HIV-1-associated cognitive/motor complex develops later in the course of the disease, suggesting that brain cells may inhibit the early productive infection and the development of neurological disease. In this study, we established an in-vitro coculture system to determine whether astrocytes can modulate HIV-1 replication in MDM. METHODS: Elutriated human monocytes were differentiated in culture, then infected with monocyte tropic HIV-1. One day after infection, MDM were co-cultured with primary astrocytes. Reverse transcriptase (RT) activity was used to monitor virus replication. RT-polymerase chain reaction (PCR), enzyme-linked immunosorbent assay (ELISA) and bioassay were used to assess cytokine production. RESULTS: Primary human astrocytes suppressed HIV-1 replication in MDM via the production of soluble factors. Cytokine inhibitors of HIV-1, such as IFN-gamma, IL-4, IL-10 and IL-13, were not detectable, whereas transforming growth factor beta (TGF-beta) was constitutively produced only in its latent form. Paraformaldehyde-fixed astrocytes, unable to secrete cytokines, failed to inhibit HIV-1. These cells caused enhanced virus replication, however, which correlated with an increase in macrophage colony stimulating factor (M-CSF) production. CONCLUSIONS: Human astrocytes can increase and decrease HIV-1 expression in MDM. An imbalance between the positive and negative effects of astrocytes may contribute to the expression of virus in the brain, and the development of HIV-1-associated cognitive/motor complex.

Procurement of population-based cancer tissue in Iowa.

We describe the first systematic survey of pathology laboratories serving Iowans to assess attitudes concerning assistance with cancer research efforts. Previous reports suggested that pathologists are reluctant to loan slides and/or paraffin tissue blocks for research purposes because of potential loss or damage, medicolegal concerns, or lack of compensation for time and effort spent in retrieving materials. In this study, we obtained survey responses from laboratory directors of 54 of the 56 pathology laboratories serving Iowans. The survey covered issues related to the availability of research materials, reimbursement for the retrieval of materials, and turnaround time for returning borrowed materials. Contrary to previous reports, we found that the laboratory directors surveyed were willing to loan slides and blocks for research purposes, provided that confidentiality is maintained, that the materials are handled properly and returned in a timely manner, and that compensation is provided.

Human immunodeficiency virus-1-infected macrophages induce inducible nitric oxide synthase and nitric oxide (NO) production in astrocytes: astrocytic NO as a possible mediator of neural damage in acquired immunodeficiency syndrome.

Nitric oxide (NO) plays an important role in normal neural cell function. Dysregulated or overexpression of NO contributes to neurologic damage associated with various pathologies, including human immunodeficiency virus (HIV)-associated neurological disease. Previous studies suggest that HIV-infected monocyte-derived macrophages (MDM) produce low levels of NO in vitro and that inducible nitric oxide synthase (iNOS) is expressed in the brain of patients with neurologic disease. However, the levels of NO could not account for the degree of neural toxicity observed. In this study, we found that induction of iNOS with concomitant production of NO occurred in primary human astrocytes, but not in MDM, when astrocytes were cocultured with HIV-1-infected MDM. This coincided with decreased HIV replication in infected MDM. Supernatants from cocultures of infected MDM and astrocytes also stimulated iNOS/NO expression in astrocytes, but cytokines known to induce iNOS expression (interferon-gamma, interleukin-1beta, and tumor necrosis factor-alpha) were not detected. In addition, the recombinant HIV-1 envelope protein gp41, but not rgp120, induced iNOS in cocultures of uninfected MDM and astrocytes. This suggests that astrocytes may be an important source of NO production due to dysregulated iNOS expression and may constitute one arm of the host response resulting in suppression of HIV-1 replication in the brain. It also leads us to speculate that neurologic damage observed in HIV disease may ensue from prolonged, high level production of NO.

Interleukin-2 inhibits HIV-1 replication in human macrophages by modulating expression of CD4 and CC-chemokine receptor-5.

OBJECTIVE: To determine the effect of recombinant human interleukin (IL)-2 on HIV-1 replication and macrophage colony stimulating factor (M-CSF) production by HIV-1-infected monocyte-derived macrophages (MDM). DESIGN: Therapeutic use of IL-2 increases the number and function of CD4+ T cells. IL-2 also increases M-CSF production and M-CSF receptor expression by human monocytes, but the subsequent effects on HIV-1 replication in MDM have yet to be determined. MDM from HIV-1-seronegative donors were cultured in the presence and absence of IL-2 and infected with HIV-1. Harvested supernatants were monitored for reverse transcriptase activity and M-CSF production. RESULTS: Reverse transcriptase activity was significantly lower when MDM cultures were treated with IL-2 for 10 days prior to infection with HIV-1. IL-2 did not stimulate production of inhibitory chemokines or cytokines, but FACS analysis revealed that expression of CD4, the primary HIV-1 receptor, and CC-chemokine receptor-5, a coreceptor used by macrophage-tropic viruses, are down modulated after treatment with IL-2. CONCLUSION: IL-2 may not only be of benefit in restoring immune function in AIDS patients, but may also help to prevent the infection of healthy macrophages by decreasing their expression of HIV-1 receptors.

The effects of general anesthesia and surgery on basal and interferon stimulated natural killer cell activity of humans.

UNLABELLED: Natural killer (NK) cells can lyse certain tumor cells as well as virally infected cells without prior sensitization. Animal studies have shown that general anesthesia (GA) alone or GA followed by surgery decreases both basal NK cytotoxicity and enhancement of NK activity by interferon (IFN). The purpose of this study was to determine whether similar inhibition of NK activity by anesthesia and surgery occurs in humans. Venous blood was drawn 1 h before and 20-24 h after surgery under isoflurane/N2O anesthesia. Peripheral blood mononuclear cells (PBMC) were assayed for basal and IFN-alpha-stimulated NK cytotoxicity using a chromium release assay with K562 cells as targets. Flow cytometry was used to enumerate NK, T-helper, and T-cytotoxic/suppressor cell populations in each sample. Basal NK activity was significantly depressed after GA and GA and surgery. Although the postoperative IFN treatment increased NK activity to the preoperative basal level, the level achieved was significantly lower than the level observed after IFN stimulation of PBMC as evaluated preoperatively. This decreased activity does not seem to be the result of a decrease in the percentage of circulating NK cells. The decrease in NK activity after anesthesia and surgery may lead to increased susceptibility to infection and/or tumor dissemination and thus needs to be explored. IMPLICATIONS: Natural killer cells can kill cancer cells and virally infected cells. This study shows that surgery with general anesthesia leads to decreased natural killer cell activity as assessed int he laboratory. This decreased natural killer cell activity may lead to infection or tumor dissemination. NK activity can be restored to presurgery levels by treating isolated NK cells with interferon-alpha.

Age-associated decline in IL-2 and IL-12 induction of LAK cell activity of human PBMC samples.

Previously we reported that young and elderly natural killer (NK) cell activity against the standard NK sensitive K562 cell line can be augmented to the same degree by IL-2 and IFN-alpha. We have extended these studies to include IL-12. Similar to IL-2 and IFN-alpha, IL-12 can enhance NK cytotoxicity to the same degree in both young and elderly samples over a wide range of doses and incubation times when K562 cells are used as targets. However, in contrast to our findings with the NK system, we have observed that induction of lymphokine activated killer (LAK) cell activity, as defined by the ability of peripheral blood mononuclear cells (PBMC) samples to lyse the normally NK resistant Daudi cell line, was significantly decreased in the elderly samples compared to young samples. Comparable age-associated differences were observed in LAK activity after induction with IL-2, IL-12, and IFN-alpha at varying doses and incubation times. We hypothesize an age-associated deficiency either in the mechanism of LAK induction or in target cell recognition.

Natural killer cell cytotoxicity in elderly humans after influenza immunization.

Previous studies have reported that human natural killer (NK) cytotoxicity can be augmented by either in vitro stimulation with influenza virus antigens or in vivo administration of killed influenza vaccine. The study demonstrating the latter conclusion reported an increase in NK cytotoxicity lasting for 4 weeks postvaccination in young subjects. We initiated our study to determine if a similar increase in NK activity was observed in an elderly population after immunization with the 1992-1993 influenza vaccine. NK activity of 34 elderly (mean age, 77.3 years) was determined at 3 time points: prevaccination, 4 to 6 weeks postvaccination, and 5 to 6 months after vaccination. In contrast to the results of the previous study, the NK cytotoxicity of our elderly subjects was not augmented by the influenza vaccine at any time tested. We also determined the number of CD56+ cells in whole-blood samples at each of the time points and found that there is no change in NK cell number after influenza vaccination.

Effects of aging on natural killer cell activity and activation by interleukin-2 and IFN-alpha.

To address the conflicting reports concerning both innate and lymphokine-inducible NK activity of elderly individuals, NK activity of peripheral blood mononuclear cells (PBMC) of 21 young (23 to 35 years old) and 43 elderly (65 to 100 years old) subjects was assessed using a 4-hr chromium release assay with K562 or Daudi cells as targets. Significantly higher innate NK cell activity was observed in elderly compared to young individuals (P < 0.001, Student t test). NK activity of both groups was enhanced to the same degree by IL-2. Although intermediate amounts of IFN-alpha (100-500 mu/10(6) cells) induced comparable maximal NK activity of both young and elderly subjects, young subjects responded better than elderly to low amounts of IFN-alpha (10 mu/10(6) cells), while higher amounts (10(3) mu/10(6) cells) reduced the NK activity of the elderly, but not young, to basal levels. IFN-alpha also expanded the range of target cells susceptible to NK activity. Untreated cells of neither young nor elderly showed activity against Daudi targets. Two-hour treatment with IFN-alpha resulted in significant activity against Daudi cells; however, this activity was significantly lower in the elderly compared to the young subjects.