Effects of dietary lipid levels on mitochondrial gene expression in low and high-feed efficient families of rainbow trout Oncorhynchus mykiss.

A 2 × 3 factorial study was conducted to evaluate the effects of dietary lipid level on mitochondrial gene expression in mixed sex rainbow trout Oncorhynchus mykiss. Practical diets with a fixed crude protein content of 42%, formulated to contain 10% (42/10), 20% (42/20) and 30% (42/30) dietary lipid, were fed to triplicate groups of either low-feed efficient (F129; mean ± s.d. = 105.67 ± 3.04 g initial average mass) or high-feed efficient (F134; mean ± s.d. = 97.86 ± 4.02 g) families of fish, to apparent satiety, twice per day, for 108 days. At the end of the experiment, diets 42/20 and 42/30 led to similar fish condition factors, which were higher than that observed with diet 42/10 (P < 0.05). F134 fish fed diet 42/10 showed the highest hepato-somatic index, while there was no significant difference among all the other treatments (P < 0.05). When the group of F134 fish fed diet 42/10 was used as the calibrator for gene expression analysis, the five genes selected for their involvement in lipid metabolism (complex I-nd1, complex III-cytb, complex IV-cox1, complex IV-cox2 and complex V-atp6) were up-regulated in the muscle and down-regulated in both the liver and the intestine. There was a significant family × diet interaction regarding nd1, cox2 and atp6 in the liver; nd1, cytb, cox1, cox2 and atp6 in the intestine, and nd1, cytb, cox1, cox2 and atp6 in the muscle (P < 0.05). The overall results of this study constitute basic information for the understanding of molecular mechanisms of lipid metabolism at the mitochondrial level in fishes.

Increased morbidity and mortality in murine cytomegalovirus-infected mice following allogeneic bone marrow transplant is associated with reduced surface decay accelerating factor expression.

Infection with cytomegalovirus (CMV) remains a significant cause of morbidity and mortality following allogeneic bone marrow transplantation (allo-BMT). The manifestations of CMV infection can range from neurological and haematological abnormalities to diminished graft survival and, in extreme cases, death. Many clinical studies have shown a direct correlation between cytomegalovirus infection and increased morbidity and mortality post allo-BMT, yet the exact mechanism is not well understood. Although driven primarily by T cell responses, the role of complement activation in acute and chronic graft-versus-host disease (GVHD) has also become more evident in recent years. The present studies were performed to examine the effects of murine cytomegalovirus (MCMV) infection on decay accelerating factor (DAF) and MCMVs role in exacerbating morbidity and mortality post-allo-BMT. Mice infected previously with a sublethal dose of MCMV (1 × 105 plaque-forming units) have reduced expression of DAF on lung tissues and lymphocytes following allo-BMT. More importantly, mortality rates post-allo-BMT in recipient DAF knock-out mice receiving wild-type bone marrow are increased, similar to wild-type MCMV-infected recipient mice. Similarly, DAF knock-out mice showed greater intracellular interferon (IFN)-γ production by lung CD8 T cells, and infection with MCMV further exacerbated both intracellular IFN-γ production by CD8 T cells and mortality rates post-allo-BMT. Together, these data support the hypothesis that MCMV infection augments morbidity and mortality post-allo-BMT by reducing surface DAF expression.

Increased weight loss with reduced viral replication in interleukin-10 knock-out mice infected with murine cytomegalovirus.

The anti-inflammatory cytokine interleukin (IL)-10 plays an important role in the regulation of host-immune responses. Here we studied the role IL-10 plays in host responses to cytomegalovirus (CMV) infection. We demonstrate that manifestations of murine CMV (MCMV) disease are more severe in IL-10 knock-out mice, despite significantly reduced levels of viral replication. Cytokine analysis of serum revealed increased levels of interferon (IFN)-gamma, monocyte chemotactic protein 1 (MCP-1) and IL-6, all of which are potent stimulators of inflammatory responses. Depletion of IFN-gamma by monoclonal antibodies in IL-10 knock-out mice failed to improve the physical condition of the mice, while increasing viral replication. In contrast, serum levels of IL-6 in the knock-out animals were unaffected by IFN-gamma depletion and remained significantly elevated early in the course of infection. These data suggest that increased weight loss observed in IL-10 knock-out mice may be attributed to the uncontrolled production of proinflammatory cytokines, including IL-6.

Force measurement and mechanical characterization of living Drosophila embryos for human medical study.

The objective of this paper is to investigate and characterize the force behaviour and mechanical properties of living Drosophila embryos using an in situ polyvinylidene fluoride (PVDF) piezoelectric microforce-sensing tool with a resolution in the range of sub-micro newtons. The Drosophila embryo is one of the most studied organisms in biological research, medical research, genetics, and developmental biology and has implications in the cure of human diseases. It is also used to study the wiring of the human brain and the nervous system. For a highly efficient and accurate microinjection of genetic material into a Drosophila embryo, it is absolutely necessary to allow close monitoring of the magnitude and direction of microinjection and other biomanipulation forces acting on the embryo during the injection process. In this paper, a networked microrobotic biomanipulation platform integrating a two-axis (two-dimensional) PVDF microforce-sensing tool is used to implement force sensing and injection of living Drosophila embryos. Based on the event synchronization for the feedback of injection video and microforce, the developed networked microrobotic platform can greatly advance operations in microinjection and biomanipulation. Through experiments, quantitative relationships between the applied force and membrane structural deformation of embryos in different stages of embryogenesis and their microinjection force behaviours were investigated. Ultimately, the technology will provide a critical and major step towards the development of automated biomanipulation for batch injection of living embryos in genetic and developmental studies, which will facilitate the development of medicine for the cure of human diseases.

Reducing the transmission of HIV-1: needle bleaching as a means of disinfection.

OBJECTIVE: To review the efficacy, safety, and proper methods for use of bleach (sodium hypochlorite) as a means of needle disinfection. DATA SOURCES: Controlled studies cited in MEDLINE between 1966 and 1999 using indexing terms: needle, bleach, HIV/AIDS, and disinfection. STUDY SELECTION AND DATA EXTRACTION: Studies were categorized based on experimental conditions produced and specific testing procedures used. DATA SYNTHESIS: Used properly, undiluted bleach (sodium hypochlorite 5.25%) appears to be an effective disinfection solution for used needles. Proper needle disinfection with undiluted bleach may reduce the risk of HIV transmission among injection drug users from needle sharing. CONCLUSION: Pharmacists can play a role in reducing HIV transmission among injection drug users by advocating cessation of drug use, drug treatment programs, and avoidance of needle sharing. Pharmacists should be prepared to educate patients who are unwilling to cease illicit drug use or participate in drug treatment programs on the proper methods of bleach disinfection of used needles.

Revising appointment, promotion, and tenure procedures to incorporate an expanded definition of scholarship: the University of Kentucky College of Medicine experience.

Scholarly activity and scholarly productivity are key features of the academic health center (AHC) and the work of college of medicine faculty. Recent changes in the academic environment of the University of Kentucky (UK) College of Medicine led to an examination of its appointment, promotion, and tenure procedures. This, in turn, led to a re-examination of the college's definition of scholarship. This article describes three of UK's scholarship-related challenges, particularly those related to clinical departments. The authors describe some of the new procedures being implemented to address these challenges; these include new faculty designations, clearer articulation of promotion procedures, explicit recognition of multiple forms of scholarship, expectations for investment in junior faculty, and mandatory discussion of faculty success in chairs' annual reviews. Faculty reactions, positive and negative, to these changes in procedures are also presented.

Cytokine production in patients with anorexia nervosa, bulimia nervosa, and obesity.

OBJECTIVE: We previously reported elevated serum levels of the cytokines interleukin-6 (IL-6) and transforming growth factor-beta (TGF-beta) in patients with anorexia nervosa (AN). We investigated the cellular production of these two cytokines and of interferon-gamma (IFN-gamma), interleukin-1alpha (IL-1alpha), and tumor necrosis factor-alpha (TNF-alpha) in subjects with AN, bulimia nervosa (BN), and obesity as well as in normal-weight control subjects. METHODS: Supernatant fluids from isolated peripheral blood mononuclear cells (PBMC) incubated with and without concanavalin A (ConA) were assayed for cytokine concentrations by enzyme-linked immunosorbent assay (ELISA). RESULTS: Significant differences across the four groups were found in the stimulated cellular production of IFN-gamma and IL-6. Stimulated IFN-gamma production was elevated in the AN group compared to controls. IL-6 production was significantly elevated in obese subjects relative to the two normal-weight groups, BN and controls, and tended to be higher in the AN group than in the controls, but not significantly so. IL-1alpha production was greater in obese subjects. CONCLUSION: The findings of increased IFN-gamma production and a tendency toward increased IL-6 production (both of which suppress food intake in animals) in individuals who severely restrict food intake suggest a potential role for these cytokines in the pathogenesis of AN. Elevated IL-6 and IL-1alpha production by PBMC in obese individuals requires further investigation to determine if these cytokines contribute to the development or perpetuation of obesity.

Prenatal HIV prevention practices in a low seroprevalence state.

The purpose of this study was to build understanding of prenatal HIV counseling and testing practices in low seroprevalence states. Responses from a 1998 population-based survey of Kentucky prenatal care providers (67% response; 312 analyzed) were compared with findings from patient focus groups. Sixty-two percent of clinicians said they routinely counsel prenatal patients with risk factors, but only 46% routinely counsel patients without risk factors. The proportions routinely offering HIV testing to patients with and without risk factors were 94% and 84%, respectively. Prenatal patients identified "fear of a positive test result" as the major barrier to test acceptance. This fear was fueled by lack of knowledge regarding the benefits of early detection. The study concludes that achieving universal prenatal HIV testing will require new strategies, such as the distribution of a standardized protocol, that address clinicians' concerns about "time burdens" without depriving patients of the opportunity to receive individualized counseling.

Human immunodeficiency virus drug resistance testing: state of the art in genotypic and phenotypic testing of antiretrovirals.

Antiretroviral drugs have significantly reduced death rates from the acquired immunodeficiency syndrome in the United States. They are highly effective in reducing viral replication, but their utility is threatened by rapid development of drug resistance. Although antiretroviral drug resistance testing is available by either genotyping or phenotyping, no consensus guidelines have been published regarding the appropriate use or interpretation of these new tests. Even though their role in clinical practice is not defined, it is important for clinicians to become familiar with relative advantages and disadvantages of genotypic and phenotypic testing and various mechanisms of antiretroviral resistance.

Adenovirus infections in hematopoietic stem cell transplant recipients.

We report a 12% incidence of adenovirus infections among 532 recipients of hematopoietic stem cell transplant (HSCT) from January 1986 through March 1997. The median time from day of stem cell infusion to first positive culture was 41 days. Recipients of allogeneic stem cells, as opposed to autologous stem cell recipients, were more likely to have a culture positive for adenovirus (16% vs. 3%; P<.0001). Pediatric patients were also more likely than adults to have a positive culture (23% vs. 9%; P<.0001). Among stem cell recipients with partially matched related donors, pediatric recipients appear to be at significantly greater risk for infection than adult recipients (P<.001). Positive cultures were associated with evidence of invasion in 64% of cases (41 of 64). A multiple logistic regression analysis showed that isolating adenovirus from more than 1 site correlated with greater risk for invasive infections (P=.002). Invasive infections were associated with poorer chance of survival.

Immunogenicity of three Haemophilus influenzae type b protein conjugate vaccines in HIV seropositive adults and analysis of predictors of vaccine response.

HIV-seropositive adults may be at increased risk of infection due to Haemophilus influenzae type b (Hib) as compared with HIV-seronegative adults. Protein conjugate vaccines have been demonstrated to induce protective levels of antibodies against Hib in immunocompetent infants and also in HIV-seropositive infants. In this study we determined the immunogenicity of three protein conjugate Hib vaccines (PRP-D, HbOC, HbNOMP) in 135 HIV-seropositive adults who received one dose of Hib vaccine. Anti-polyribosylribitol phosphate (PRP) antibodies were measured at 0, 1, 3 and 12 months postimmunization by the Farr method. We demonstrate that all three vaccines are highly immunogenic and result in protective (> 1.0 microg/ml) levels of antibody. Overall the anti-PRP antibody level was > 1.0 microg/ml in 26% of patients preimmunization, 91% at both 1 and 3 months, and 79% at 12 months postvaccination. Comparison of responses to the three vaccines over time demonstrated differences in the mean geometric anti-PRP antibody level at 1 month (p=0.03) and the 12 month time points (p=0.03) with lower geometric mean levels in the HbNOMP group, though baseline differences in groups limit the interpretation of these findings. In a univariate analysis of baseline characteristics which predicted poor vaccine response, low total IgG2 levels preimmunization predicted a poor antibody response at 1 month (p < 0.01) and at 12 months (p=0.05), while low CD4 T-cell count predicted poor response at 12 months (p < 0.01). We conclude that all three US licensed protein conjugate Hib vaccines are immunogenic in HIV-seropositive adults, and that baseline CD4 T-cell count and IgG2 levels predict the likelihood of antibody response to vaccine.

Changes in cytokine levels during reactivation of Toxoplasma gondii infection in lungs.

We studied cytokine proteins and mRNAs in mice with two forms of Toxoplasma gondii pneumonia resulting from reactivation of infection. In the first form, mice were infected with T. gondii, developed and recovered from systemic disease, and then developed pneumonia 3 weeks later. As pulmonary inflammation developed, levels of cytokine mRNAs for gamma interferon (IFN-gamma), interleukin-2 (IL-2), IL-4, and IL-10 increased in bronchoalveolar lavage (BAL) cells or lung tissue, and the level of IFN-gamma protein increased in BAL fluid. The second form of pneumonia occurred as a complication of primary cytomegalovirus (CMV) disease in mice with dormant T. gondii infection. During CMV disease, IL-2 mRNA levels decreased in lung tissue, IL-10 protein levels increased in lung tissue, and IL-10 protein levels increased in BAL fluid. As the mice recovered from CMV disease, T. gondii infection was reactivated in the lungs and was manifested as T. gondii pneumonia. During CMV-induced T. gondii pneumonia, IFN-gamma, IL-2, IL-4, and IL-10 mRNA levels increased in BAL cells or lung tissue, and both IFN-gamma and IL-2 protein levels increased in BAL fluid. We concluded that both forms of T. gondii pneumonia are accompanied by increases in both type 1 T-helper and type 2 T-helper cytokine levels in lungs. The mechanism of CMV-induced reactivation of T. gondii infection in lungs may involve local decreases in IL-2 levels and/or increases in IL-10 levels.

Renal manifestations of hepatitis C infection.

Hepatitis C is an important cause of renal disease, and renal complications may be the presenting manifestation of hepatitis C infection. About half of patients present with evidence of renal insufficiency, and up to one quarter present with nephrotic syndrome. Others present with proteinuria or evidence of diminished renal function. The pathogenesis of hepatitis C-associated renal disease remains incompletely defined, but most evidence suggests that glomerular injury results from deposition of circulating immune complexes in the subendothelium and mesangium. Membranoproliferative glomerulonephritis, with or without cryoglobulinemia, is the most common renal lesion. Interferon alpha-2b is currently the treatment of choice. However, success is limited, with many patients failing to respond or suffering relapse upon discontinuation of therapy. Studies of newer treatment modalities, such as longer courses of interferon or the use of ribavirin or immunosuppressive agents, are underway. Hepatitis C-associated renal disease may progress to end-stage renal failure requiring dialysis in about 10% of patients.

Hydroxyurea to inhibit human immunodeficiency virus-1 replication.

Treatment of human immunodeficiency virus (HIV) infection continues to be a challenge. Drug regimens that include two nucleoside reverse transcriptase inhibitors and a protease inhibitor are now the standard of care. These regimens require strict patient adherence and have numerous adverse effects at a high cost, so clinicians must continue to explore other therapeutic options. Hydroxyurea is a ribonucleotide reductase inhibitor that may have efficacy against HIV. We conducted a critical review of the literature to examine the utility of hydroxyurea-based drug combinations.

Role of interferon-gamma in murine cytomegalovirus infection.

Interferon-gamma has well-documented antiviral and immunomodulatory activity, but its role in the control of cytomegalovirus (CMV) infection is not well studied. In a mouse model of murine CMV (MCMV) disease, interferon-gamma concentrations in serum but not in bronchoalveolar lavage fluid increased in response to viral infection. Serum interferon-gamma levels peaked at day 2 in the relatively resistant C57BL/6 mice, and, in contrast, did not peak until day 6 in susceptible BALB/c mice. Mice genetically lacking interferon-gamma (GKO) were more susceptible to MCMV, although strain differences persisted, with C57BL/6 GKO mice experiencing less severe MCMV disease than BALB/c GKO mice. Treatment of MCMV-infected BALB/c mice with exogenous interferon-gamma starting 2 days after viral infection had a modest protective effect at lower interferon-gamma doses (10(4) units), but interferon-gamma therapy markedly increased morbidity and mortality when higher doses (10(5) units) were used. We conclude that interferon-gamma plays a significant role in host response to MCMV and that the cytokine has dose- and time-dependent beneficial and adverse effects.

Leptin in anorexia nervosa.

Serum leptin levels are low in untreated anorexia nervosa, but studies of the exact relationship between leptin and body weight and the impact of refeeding in anorectics are limited. Therefore, we studied serum leptin, insulin-like growth factor I, and other endocrine parameters in female anorectics before and after gaining weight and in female normal body weight controls. Leptin levels in untreated anorectics were significantly lower than those in normal body weight controls (3.6 +/- 1.6 vs. 12.0 +/- 6.9 ng/mL; P < 0.001), and they uncoupled from body weight in a nonlinear relationship, suggesting a threshold effect at lowest body weights. Leptin increased significantly with refeeding (5.6 +/- 3.8 ng/mL; P < 0.01). The significant linear correlations of leptin with body mass index in the anorectics after weight gain and in normal body weight controls (r = 0.69; P < 0.001 and r = 0.76; P < 0.001, respectively) are consistent with a normal physiological increase in leptin with weight gain. Leptin and insulin-like growth factor I were highly correlated, even after controlling for body weight (r = 0.63; P = 0.001) during starvation, but were no longer significantly correlated after body weight gain in the anorectics or the normal body weight controls. Further studies are necessary to elucidate the relationship of leptin to neuroendrocrine abnormalities seen in starvation and to determine a possible contribution of leptin to difficulties with weight restoration in anorexia nervosa.