In vivo protective anti-HIV immune responses in non-human primates through DNA immunization

An effective immune response involves the specific recognition of and elimination of an infectious organism at multiple levels. In this context DNA immunization can present functional antigenic proteins to the host for recognition by all arms of the immune system, yet provides the opportunity to delete any genes of the infectious organism which code for antigens or pieces of antigens that may have deleterious effects. Our group has developed the use of nucleic acid immunization as a possible method of vaccination against Human immunodeficiency virus type 1 (HIV-1) [1,2,3,10,11,12]. Sera from non-human primates immunized with DNA vectors that express the envelope proteins from HIV-1 contain antibodies specific to the HIV-1 envelope. These sera also neutralize HIV-1 infection in vitro and inhibit cell to cell infection in tissue culture. Analysis of cellular responses is equally encouraging. T cell proliferation as well as cytotoxic T cell lysis of relevant env expressing target cells were observed. In addition, evidence that DNA vaccines are capable of inducing a protective response against live virus was demonstrated using a chimeric SIV/HIV (SHIV) challenge in vaccinated cynomologous macaques. We found that nucleic acid vaccination induced protection from challenge in one out of four immunized cynomolgus macaques and viral load was lower in the vaccinated group of animals versus the control group of animals. These data encouraged us to analyze this vaccination technique in chimpanzees, the most closely related animal species to man. We observed the induction of both cellular and humoral immune responses with a DNA vaccine in chimpanzees. These studies demonstrate the utility of this technology to induce relevant immune responses in primates which may ultimately lead to effective vaccines.

Efficacy and Tolerability of Low-dose Simvastatin and Niacin, Alone and in Combination, in Patients With Combined Hyperlipidemia: A Prospective Trial

BACKGROUND: Combination lipid-lowering therapy may be desirable in patients with elevated low-density lipoprotein cholesterol, high triglycerides, and low high-density lipoprotein cholesterol. This study was conducted to determine the lipid-lowering efficacy of the combination of low-dose simvastatin and niacin in patients with combined hyperlipidemia and low high-density lipoprotein cholesterol. METHODS AND RESULTS: In this multicenter, prospective, randomized trial, 180 patients with hypercholesterolemia and hypertriglyceridemia and/or low high-density lipoprotein cholesterol were randomized to combination simvastatin (10 mg/day) and niacin (0.75 g/day) or to either drug alone for 9 weeks. The dose of niacin was doubled (from 0.75 g/day to 1.5 g/day) in both the combination and niacin arms for the remaining 8 weeks. The combination of simvastatin, 10 mg/day, and niacin, 1.5 g/day, reduced total, low-density lipoprotein, and very low-density lipoprotein cholesterol and triglycerides by 24%, 29%, 45%, and 31%, respectively, while increasing high-density lipoprotein cholesterol by 31%. The addition of niacin to simvastatin did not enhance the low-density lipoprotein cholesterol by 31%. The addition of niacin to simvastatin did not enhance the low-density lipoprotein cholesterol-lowering effect of simvastatin; however, the combination was more effective than either monotherapy at raising high-density lipoprotein cholesterol and lowering very low-density lipoprotein cholesterol (P <.05). More patients discontinued treatment because of an adverse event in the niacin (P <.03) and combination groups (P =.06) than the simvastatin group. CONCLUSIONS: Treatment of patients with combined hyperlipidemia and/or low high-density lipoprotein with combination low-dose simvastatin and niacin resulted in large reductions in total, low-density lipoprotein, and very low-density lipoprotein cholesterol and increases in HDL cholesterol. Although the combination was well tolerated in the current trial, its safety needs to be evaluated in larger trials of longer duration.

[Sick leave in relation to occupational environment and family conditions. An analysis of data from a study on health and morbidity performed 86]

Data previously collected by the Danish Institute of Clinical Epidemiology (DICE) in 1986/87 by a structured interview of a sample of the adult Danish population was analysed to evaluate sick leave among 1) persons with preschool children, 2) persons with either physically demanding work or with exposure to chemicals, and 3) persons with mentally demanding employment. Average absence from work in the year previous to the interview was increased in unmarried women with preschool children (9.8 days). Average absence from work increased in a stepwise fashion from 4.7 to 18.7 days with increasing physical work loads, and from 5.6 to 10.1 days with increasing exposure to chemicals. In the group with mentally demanding work, the increased was from 6.3 to 20.0 days up to a load level of five. Risk of long lasting (above 10 days) sick leave was increased among the 52.9% of persons in the study base who either had physically demanding work or who were exposed to chemicals, prevalence rate 1.91 (1.56-2.35, 95% CI), as well as among the 20.9% of persons in the study base with mentally demanding work, prevalence rate 1.68 (1.38-2.05, 95% CI). Logistic regression analysis revealed statistically significant odds ratios also when age, tobacco smoking, marital status, chronic disease and overlap between the risk groups were taken into consideration.

Immunotoxicity of cocaethylene

This report describes the response of normal human T cells to stimulation in vitro in the presence of nano-micromolar concentrations of cocaethylene. Thymidine incorporation by concanavalin A-stimulated peripheral blood mononuclear cells was generally blunted by cocaethylene, albeit to different degrees depending upon the donor tested. The formation of concanavalin A-induced blast cells was decreased by increasing concentrations of cocaethylene. The production of interleukin-2 was also blunted in a dose-dependent fashion by cocaethylene, and this outcome was more consistently observed in stimulated peripheral blood mononuclear cells, compared to unseparated whole blood preparations. An inverse dose dependence was obtained in relation to the response of blast cells to recombinant human interleukin-2 in the presence of cocaethylene. These lines of evidence, taken together with our preliminary studies aimed at testing the effect of cocaethylene on the expression of certain membrane markers of activation (i.e., interleukin-2 receptor, transferrin receptor, serine aminopeptidase IV) and the expression of the proliferating cell nuclear antigen (cyclin PCNA), suggest that cocaethylene modulates relatively early events following T cell stimulation probably related to the interleukin-2 system.

Mapping of neutralization epitopes on infectious pancreatic necrosis viruses

We have characterized and mapped variable and conserved neutralization epitopes of serogroup A strains of aquatic birnaviruses. Epitope mapping using monoclonal antibodies (MAbs) and Escherichia coli-expressed deletion fragments of VP2 of the N1 strain of infectious pancreatic necrosis virus (IPNV) demonstrated that two variable epitopes, H8 and B9, depend on the variable region between amino acid 204-330. A conserved neutralization epitope, F2, was shown to depend on the same region as epitopes H8 and B9 but was additionally dependent on amino acids between 153-203. The neutralization epitopes H8, B9 and F2 were also shown to overlap by a competitive binding assay. One conserved neutralization epitope, AS-1, was not exposed on any of the recombinant VP2 deletion fragments and was therefore not possible to map. However, the MAbs AS1 and F2 were partly competitive indicating that these epitopes are overlapping. All neutralization epitopes were independent of a conserved non-neutralization epitope, E4. Our results demonstrate that the central third of VP2 contains several partly overlapping neutralization epitopes, both variable and conserved among serogroup A strains of IPNV.

Steroid receptor-mediated modulation of CD4+CD62L+ cell homing. Implications for drug abusers

Naive human T cells home to peripheral lymph nodes via the leukocyte endothelial cell adhesion molecule-1 (LECAM-1, l-selectin, CD62L, Leu8 antigen) they express. We enriched populations of CD4+CD62L+ cells (attachment of Leu8+ T cells to flasks coated with anti-mouse IgG (AIS); Leu8+ T cells, 82.3% pure (+/- 2.3%), enriched for CD4+ cells by incubation over flasks coated with anti-CD4 antibody--this 3-4-day procedure yields an 88 +/- 1.4% recovery. Cells were treated with dexamethasone in vitro for 24-48 h, and monitored by flow cytometry. We found severe toxicity by this steroid at high concentration (10(-6) M: 35% decrease in CD62L+ T cells, 22% drop specifically in CD4+CD62L+ cells), suggesting the onset of receptor-mediated apoptotic events. The toxicity was dose dependent (5% and 7% drop in CD62L+ T and CD4+CD62L+ cells, respectively, at 10(-9) M, the concentration found in plasma 10 h following the administration of 1 mg dexamethasone). One mg of dexamethasone given to normal subjects leads to a 15-20% decrease in circulating CD4+CD62L+ cells at 10 h. This tends to be correlated with a drop in the number of glucocorticoid cytosolic receptors. Thus, steroids seem to modulate CD4+CD62L+ cell homing by means of receptor-mediated mechanisms.

Cocaine blunts human CD4+ cell activation

Cocaine is reported to be immunotoxic. The biochemical mechanisms responsible for the immunopharmacological outcomes of cocaine in vivo and in vitro remain, however, to be fully elucidated. Our experimental data confirm that exposure of normal human T cells to micromolar concentrations of cocaine modulates T-cell responses to stimulation by a variety of stimuli, and indicate that cocaine impairs early activation events during CD4+ but not CD4- T-cell stimulation. Pre-incubation of enriched CD4+ T-cell subpopulations that express the homing receptor CD62L with nanomolar concentrations of the endogenous opioid peptide beta-endorphin leads to a more severe impairment of activation than that noted following pre-incubation with micromolar concentrations of cocaine alone. These findings begin to elucidate the molecular and cellular mechanisms of the immunopathology of cocaine. Our data support the proposition that cocaine abuse may place cocaine-abuser HIV-seropositive individuals at increased risk of opportunistic infections.

Preference for darker faces in photographs at different phases of the menstrual cycle: preliminary assessment of evidence for a hormonal relationship

Six pairs of photographs showing human faces of both sexes were presented to 98 women who had to choose the more pleasing one of each pair. Faces within each pair were identical except for a slight difference in complexion. For women not taking oral contraceptives, skin-color preference differed significantly between two groups of subjects classified according to the current phase of their self-reported menstrual cycle: darker male faces were judged more positively by subjects in the phase when the estrogen/progesterone ratio was expected to be high than by those in the phase when this ratio was expected to be low. Female faces evoked no such cyclic response. Users of oral contraceptives showed no cyclic response to either male or female faces. These results suggest a mental mechanism whose inputs are (a) hormonal state, (b) visual identification of the sex of the face being observed, and (c) visual recognition of complexion, and whose output enters into evaluation of male and female faces. Replication with direct measures of hormonal state is recommended.

Unknown primary carcinoma: natural history and prognostic factors in 657 consecutive patients

PURPOSE

To evaluate the natural history, validate previous observations, and identify prognostic factors in patients with unknown primary carcinoma (UPC).

PATIENTS AND METHODS

Nine hundred twenty-seven consecutive patients referred to the M.D. Anderson Cancer Center with a preliminary diagnosis of UPC were prospectively identified. A standardized evaluation narrowed the study population to 657 patients with UPC. All data were recorded and computerized for storage, retrieval, and analysis. The primary end point for the study was survival, which was calculated from the first day of patient registration. Survival curves were estimated using the Kaplan-Meier method and compared using the Cox-Mantel log-rank test. To identify important prognostic factors, univariate and multivariate analyses were conducted.

RESULTS

The demographics of the UPC patient population mirrored those of the general population of patients referred to our cancer center except for an excess of men among the UPC patients. Most patients had histologic or cytologic evidence of adenocarcinoma and had more than one organ site metastatically involved. Univariate and multivariate analyses identified numerous important prognostic factors with a significant influence on survival, including sex, number of organ sites involved, specific organ sites involved, and pathologic subtypes.

CONCLUSION

This study validated previously identified important prognostic factors for survival in UPC. Additional variables that had an impact on survival were identified and the complex interaction of the factors was explored. As patient numbers increase, this database will be able to provide further analyses of patient subsets and potentially relate specific clinical features to the evolving molecular and biochemical understanding of these malignancies.

Absence of HTLV-1 related sequences in MS from high prevalence areas in western Norway

In Western Norway, long-term follow up epidemiological studies have revealed significant increases in the incidence and prevalence rates of multiple sclerosis (MS) in stable populations, indicating the impact of exogenous factors. In this study 183 MS patients and 102 controls from high prevalence areas in Western Norway were investigated for human T-lymphotropic virus type I (HTLV-1) related sequences by polymerase chain reaction. Using primers targeting the gag, pol and env genes in the HTLV-1 provirus genome, no amplification products were detected in the 183 MS patients or 102 controls. The results strongly suggest that neither HTLV-1 nor a closely related retrovirus participate in the aetiology of MS.

Modulation of cisplatin resistance by 2'-deoxy-5-azacytidine in human ovarian tumor cell lines

The sequential administration of 2'-deoxy-5-azacytidine (DAC) and cisplatin frequently results in synergistic cytotoxicity against human cancer cell lines (Frost P, et al Cancer Res 50:4572-4577, 1990) including the cisplatin resistant HEY ovarian cancer cell line. In this series of in vitro experiments the effect of DAC on cisplatin resistance was evaluated in two cisplatin resistant ovarian cell lines, C13* and A2780/DDP, and by varying the concentration ratio of DAC to cisplatin against the HEY cell line. For C13* and A2780/DDP sequential exposure to DAC and cisplatin resulted in synergy and a one to three-fold decrease in the concentration of cisplatin required to achieve defined levels of cytotoxicity. Augmentation of the synergistic interaction was also observed with the HEY line suggesting that increasing the concentration of DAC relative to cisplatin could result in improved modulation of cisplatin resistance for some highly cisplatin resistant lines. Since the concentrations of DAC and cisplatin required in vitro to observe these interactions are frequently achievable in human plasma, the clinical value of DAC modulation of cisplatin resistance could be tested in appropriately designed clinical trials.

p53 gene mutation spectrum in human unknown primary tumors

Mutations affecting the p53 gene are associated with many human malignancies, but little is known about changes in p53 in unknown primary tumors (UPTs), which are characterized as tumors with advanced stages of malignancy. We therefore investigated the frequency of p53 mutations in a series of 15 unknown primary tumor biopsies and eight cell lines established from UPTs. Mutations in the conserved regions of the p53 gene were verified by single-strand conformation polymorphism analysis of exons 5-9 and were verified by direct DNA sequencing of polymerase chain reaction products. A point mutation leading to an amino acid change in the p53 protein was found in six cases, and a mutation causing a change to termination was found in one case. A frameshift mutation was observed in one cell line. In one patient and one cell line we observed more than one mutation in the p53 coding sequence. Overall, the frequency of mutations that changed the p53 coding sequence in the UPTs we studied was 26% (6/23). Mutations were distributed in eight codons of the p53 gene. Seven of these tumors showed a reduction to homozygosity at the p53 allele, but one tumor apparently retained heterozygosity. We conclude that although UPTs represent highly metastatic advanced tumors that are expected to have a high incidence of p53 mutations, the frequency of p53 mutations is relatively low, suggesting that p53 mutations may not play a major role in the development and progression of this unique tumor type.

Organic micropollutants in Swiss sewage sludge

Sludges from sixteen municipal and eleven industrial Swiss sewage treatment plants were analysed for adsorbable organic compounds (AOX), chlorinated pesticides, polychlorinated biphenyls and polycyclic aromatic hydrocarbons. Except for the AOX values, which were significantly higher (p < 0.05) in industrial sludges, there was no significant difference between industrial and municipal sludges. The AOX values did not correlate with any of the measured pollutants. The methods employed (capillary GC-MS and GC-electron-capture detection) proved to be suitable for monitoring organic micropollutants in industrial and municipal sewage sludges.

Conversion of an immunogenic human immunodeficiency virus (HIV) envelope synthetic peptide to a tolerogen in chimpanzees by the fusogenic domain of HIV gp41 envelope protein

The fusogenic (F) domain of human immunodeficiency virus (HIV) gp41 envelope (env) protein has sequence similarities to many virus and mediates the fusion of HIV-infected cells. During a survey of the immunogenicity of HIV env peptides in chimpanzees, we have observed that HIV peptide immunogenicity was dramatically altered by the NH2-terminal synthesis of the gp41 F domain to an otherwise immunogenic peptide. We compared two hybrid peptide types comprised of T helper (Th) and B cell epitopes of HIV gp120 env protein for their immunogenicity in chimpanzees. The Th-B epitope hybrid peptides contained the HIV gp120 Th cell determinant, T1 (amino acids [aa] 428-440)-synthesized NH2 terminal to gp120 V3 loop peptides, which contain B cell epitopes that induce anti-HIV-neutralizing antibodies (SP10IIIB [aa 303-321] and SP10IIIB [A] [aa 303-327]). The F-Th-B peptide contained the HIV gp41 F domain of HIVIIIB gp41 (aa 519-530)-synthesized NH2 terminal to the Th-B peptide. Whereas Th-B peptides were potent immunogens for chimpanzee antibody and T cell-proliferative responses, the F-Th-B peptide induced lower anti-HIV gp120 T and B cell responses. Moreover, immunization of chimpanzees with F-Th-B peptide but not Th-B peptides induced a significant decrease in peripheral blood T lymphocytes (mean decrease during immunization, 52%; p < 0.02). Chimpanzees previously immunized with F-Th-B peptide did not respond well to immunization with Th-B peptide with T or B cell responses to HIV peptides, demonstrating that the F-Th-B peptide induced immune hyporesponsiveness to Th and B HIV gp120 env determinants. These observations raise the hypothesis that the HIV gp41 env F domain may be a biologically active immunoregulatory peptide in vivo, and by an as yet uncharacterized mechanism, promotes primate immune system hyporesponsiveness to otherwise immunogenic peptides.

2'-deoxy-5-azacytidine increases binding of cisplatin to DNA by a mechanism independent of DNA hypomethylation

The chemotherapeutic agents 2'-deoxy-5-azacytidine (DAC) and cisplatin (cDDP) have been shown in vitro to be synergystic in their cytotoxicity toward human tumour cells. We have investigated possible molecular mechanisms underlying this synergy using the plasmid pSVE3 in vitro and after transfection into CMT3 cells. Increased binding of cDDP to DAC-substituted DNA generated in vivo was confirmed by flameless atomic absorption spectrophotometry (FAAS). The plasmid used in these experiments was unmethylated suggesting that DAC was effective in enhancing cDDP binding to DNA without acting as a hypomethylating agent, but by directly changing the topology of DNA. The role of DNA methylation in cDDP binding was studied using methylated and unmethylated plasmid incubated in vitro with cDDP. Restriction analyses and FAAS measurement of bound platinum indicated that methylated DNA bound more cDDP than unmethylated DNA. In addition, in vivo studies confirmed the in vitro observations since replication of methylated plasmid was inhibited to a greater extent than unmethylated plasmid.

[UV cured acrylates--potent contact allergens in the occupational environment]

Allergic contact dermatitis is still an important disease in occupational medicine. Acrylic compounds are known to be potent contact sensitizers causing allergic eczema after occupational exposure. To illustrate the problem and the need for preventive arrangements the authors present an unusual clustering of allergic contact dermatitis in three technicians who produced hearing aids using ultraviolet cured akrylate compounds. All three technicians developed eczema on their fingers few months after introduction of the new acrylate compounds in the production. Skin patch testing with the products confirmed that sensitization.

Identification of ras oncogene mutations in the stool of patients with curable colorectal tumors

Colorectal (CR) tumors are usually curable if detected before metastasis. Because genetic alterations are associated with the development of these tumors, mutant genes may be found in the stool of individuals with CR neoplasms. The stools of nine patients whose tumors contained mutations of K-ras were analyzed. In eight of the nine cases, the ras mutations were detectable in DNA purified from the stool. These patients included those with benign and malignant neoplasms from proximal and distal colonic epithelium. Thus, colorectal tumors can be detected by a noninvasive method based on the molecular pathogenesis of the disease.

The use of molecular genetic markers to demonstrate the effect of organ environment on clonal dominance in a human renal-cell carcinoma grown in nude mice

Transduction of the SN12C human renal-cell carcinoma line with the neoR gene produces a genetically "tagged" cell population within which individual clones can be identified if they dominate the tumor during its growth in vivo. We used this technique to determine whether the clones that dominate the primary local tumor and its metastases are the same or different when the tumor is growing in different organ sites in nude mice. The results show that clonal dominance is influenced by the organ environment in which the primary tumor grows, i.e., distinct clones dominated in the kidney, colon and subcutaneous sites. In addition, tumors grown in the orthotopic site (kidney) were all populated by the same dominant clones, and each distant visceral metastasis retained the same clonality. SN12C neoR-cells grown in an epithelial, ectopic site (colon) produced tumors with uniquely different dominant clones, and their visceral metastases retained the dominant pattern expressed by the parent tumor from which they were derived. In contrast, SN12C tumors growing subcutaneously showed a random pattern of clonal dominance in both their primary and metastatic sites. Parallel cytogenetic analyses could not demonstrate these patterns. We conclude that the organ environment significantly influences clonal dominance of human renal carcinoma and that tumor injection into orthotopic sites may produce a more reproducible selection of dominant clones.