Multicenter randomized trial of fluconazole versus amphotericin B for treatment of candidemia in non-neutropenic patients

A randomized trial was conducted to compare the efficacy and safety of fluconazole versus that of amphotericin B in the treatment of candidemia in non-neutropenic adults. Enrollment was stratified by disease severity (APACHE II score). Patients were randomized (1:1) to receive amphotericin B 0.6 mg/kg/day (cumulative dose 8 mg/kg) or fluconazole 800 mg intravenous loading dose, then 400 mg daily for four weeks (intravenous for at least 10 days). Patients were monitored for six months. A total of 106 patients were enrolled. A protocol amendment implemented midway through the trial required patients to be removed from the study and treated with amphotericin B if species identification indicated candidemia due toCandida glabrata orCandida krusei. Baseline characteristics were similar for the two groups; 103 patients (fluconazole, 50; amphotericin B, 53) met the major enrollment criteria. The intention-to-treat analysis indicated successful therapy in 50% of fluconazole recipients compared to 58% of the amphotericin B group (p=0.39; one-sided 95% Cl, –8 to 24%). The efficacy analysis included 84 patients (fluconazole, 42; amphotericin B, 42); successful outcomes were observed in 57% and 62% of cases in the fluconazole and amphotericin B groups, respectively (p=0.66: one-sided 95% Cl, –12 to 22%). The mortality at day 14 for the fluconazole group was 26% and for the amphotericin B group 21% (p=0.52; chi-square test) and remained similar throughout the course of follow-up. Drug-related adverse events were more frequent with amphotericin B than with fluconazole and prompted switching of therapy for two (4%) and zero cases, respectively. Fluconazole and amphotericin B were associated with similar clinical response rates and survival in the treatment of candidemia among non-neutropenic patients; however, drug-related adverse events were more frequent with amphotericin B.     

Replication of human adenoviruses in guinea pig embryo cells: an ultrastructural study

Summary Guinea pig embryo (GPE) cells showed different degrees of susceptibility to human adenovirus types as determined by virus infectivity assay and electron microscopic examination. Adenovirus 2 and 5 induced extensive cellular changes and produced high titers of infectious virus in GPE cells as in human cells. Mature progeny virus and protein crystals were observed in both cell types. Adenovirus 7 induced some cellular changes in GPE cells but only a small number of cells yielded progeny virus as determined by electron microscopy. Adenovirus 3, 8 and 31 induced some cellular changes but no progeny virus was found under electron microscopic examination. Characteristic fibers were observed in nuclei of adenovirus 31 infected cells. The ability of human adenovirus 2 and 5 to replicate in GPE cells is an example of an unusual cross-species biological property of certain adenovirus types. This property may be useful as a biological marker for these virus types.With 8 Figures     

Novel proteins with binding specificity for DNA CTG repeats and RNA CUG repeats: implications for myotonic dystrophy

While an unstable CTG triplet repeat expansion is responsible for myotonic dystrophy, the mechanism whereby this genetic defect induces the disease remains unknown. To detect proteins binding to CTG triplet repeats, we performed bandshift analysis using as probes double- stranded DNA fragments having CTG repeats [ds(CTG)6-10] and single- stranded oligonucleotides having CTG repeats ss(CTG)8 or RNA CUG triplet repeats (CUG)8. The source of protein was nuclear and cytoplasmic extracts of HeLa cells, fibroblasts and myotubes. Proteins binding to the double-stranded DNA repeat [ds(CTG)6-10], were inhibited by nonlabeled ds(CTG)6-10, but not by a non-specific DNA fragment (USF/AD-ML). Another protein binding to ssCTG probe and RNA CUG probe was inhibited by nonlabeled (CTG)8 and (CUG)8. Nonlabeled oligos with different triplet repeat sequences, ss(CAG)8 or ss(CGG)8, did not inhibit binding to the ss(CTG)8 probe. However, when labeled as probes, the (CAG)8 and (CGG)8 bound to proteins distinct from the CTG proteins and binding was inhibited by nonlabeled (CAG)8 or (CGG)8 respectively. The protein binding only to the RNA repeat (CUG)8 was inhibited by nonlabeled (CUG)8 but not by nonlabeled single- or double-stranded CTG repeats. Furthermore, the CUG-BP exhibited no binding to an RNA oligonucleotide of triplet repeats of the same length but having a different sequence, CGG. The CUG binding protein was localized to the cytoplasm, whereas dsDNA binding proteins were localized to the nuclear extract. Thus, several trinucleotide binding proteins exist and their specificity is determined by the triplet sequence. The novel protein, CUG-BP, is particularly interesting since it binds to triplet repeats known to be present in myotonin protein kinase mRNA which is responsible for myotonic dystrophy.      

A phage-displayed single chain variable fragment that interacts with hepatitis B core antigen: library construction, selection and diagnosis.

BACKGROUND: Phage display is an alternative method for constructing and selecting antibodies with desired specificity towards an antigen. OBJECTIVES: To construct a library of single chain variable fragment (ScFv) towards hepatitis B core antigen (HBcAg). To isolate a ScFv phage clone that interacts with HBcAg and to develop a phage-ELISA for detecting the antigen. STUDY DESIGN: Mice were inoculated with HBcAg and RNA was extracted from their spleen cells. The genes encoding heavy (V(H)) and light (V(L)) chains were amplified, linked via PCR and cloned into a phagemid vector. Phage particles displaying ScFv were panned against HBcAg and a selected clone was characterized and employed as a diagnostic reagent for detecting HBcAg in serum samples. RESULTS: A phage clone that interacts with HBcAg was selected from the antibody library. The binding of the phage to HBcAg was inhibited by a cyclic peptide bearing the WSFFSNI sequence. A phage-ELISA was established using the recombinant phage and as low as 10ng of HBcAg can be detected by the assay. CONCLUSION: The ScFv displayed on the surface of filamentous phage is an alternative choice for diagnosis of HBcAg in serum samples.     

Increased frequency of rheumatoid factor precursor B lymphocytes after immunization of normal adults with tetanus toxoid.

Vaccination of normal adults with tetanus toxoid induced a two-three-fold rise in the frequency of IgM anti-IgG (rheumatoid factor, RF) B lymphocytes inducible by the polyclonal B cell activator, Epstein-Barr virus. The increase in IgM-RF precursors occurred earlier, was greater in magnitude, and was more sustained than the change in plasma IgM-RF. It was associated with a rise in total IgM levels, and correlated positively with the magnitude of the IgG anti-tetanus antibody response, but not with levels of circulating immune complexes. The ability of apparently innocuous infections and immunizations to increase the frequency of IgM-RF precursor B lymphocytes may be the reason for the previously noted expansion in this autoreactive B cell pool between birth and adulthood.     

Duke Surgery Research Central: an open-source Web application for the improvement of compliance with research regulation

Background  

Although regulatory compliance in academic research is enforced by law to ensure high quality and safety to participants, its implementation is frequently hindered by cost and logistical barriers. In order to decrease these barriers, we have developed a Web-based application, Duke Surgery Research Central (DSRC), to monitor and streamline the regulatory research process.     

A microplate assay for <Emphasis Type="Italic">Leishmania amazonensis</Emphasis> promastigotes expressing multimeric green fluorescent protein

Convenient and economical assays capable of screening many compounds are vital to advance the development of drug therapy. This is particularly important for many of the infections that occur mainly in the Third World. The development of such a spectrofluorometric assay for the protozoan parasite Leishmania is presented here. Using multimeric (four monomers) green fluorescent protein (GFP), Leishmania amazonensis promastigotes were generated with brightness measurable in 96-well microtiter plates. The promastigotes maintained the parental characteristics, were infective to murine macrophages and to mice, and the level of GFP fluorescence corresponded to the number of inoculated cells. The feasibility of using this assay for testing drugs kinetically and in a concentration-dependent manner, under microplate culture condition, was demonstrated with amphotericin B and the herbicide oryzalin, respectively. This assay is the first to allow a real-time analysis of antileishmanial agents with live promastigotes. The method of expressing multimeric GFP for in vitro drug screening is likely to be extendable to many species of parasitic protozoa.     

Blood pressure in adults with short stature skeletal dysplasias

Hypertension, compounded by obesity, contributes to cardiovascular disease and mortality. Data describing hypertension prevalence in adults with short stature skeletal dysplasias are lacking, perhaps due to poor fit of typical adult blood pressure cuffs on rhizomelic or contracted upper extremities. Through health screening research, blood pressure was measured in short stature adults attending support group meetings and skeletal dysplasia clinics. Blood pressure was measured with a commercially available, narrower adult cuff on the upper and/or lower segment of the arm. Height, weight, age, gender, diagnosis, exercise, and medications were collected. Subjects were classified as normotensive, prehypertensive, or hypertensive for group analysis; no individual clinical diagnoses were made. In 403 short stature adults, 42% were hypertensive (systolic >140, diastolic >90 OR taking antihypertensive medications). For every BMI unit and 1 kg weight increase in males, there was a 9% and an 8% increase, respectively, in the odds of hypertension versus normotension. In females, the increase was 10% and 6%, respectively. In those with achondroplasia, the most common short stature dysplasia, males (n = 106) had 10% greater odds of hypertension versus normotension for every BMI unit and kilogram increase. In females with achondroplasia (n = 128), the odds of hypertension versus normotension was 8% greater for each BMI unit and 7% for each additional kilogram. These data suggest a high population prevalence of hypertension among short stature adults. Blood pressure must be monitored as part of routine medical care, and measuring at the forearm may be the only viable clinical option in rhizomelic short stature adults with elbow contractures.     

Regulation of Epstein-Barr virus infection by recombinant interferons. Selected sensitivity to interferon-gamma

Interferons (IFN) are antiviral proteins that may be important in mediating cellular defenses against Epstein-Barr virus (EBV) infection. However, the means by which IFN-alpha, -beta and -gamma modify EBV infectivity are not clear. We have evaluated the effects of purified recombinant preparations of all three classes of IFN on EBV-induced B lymphocyte proliferation and Ig secretion. When added early after EBV infection, all three recombinant IFN reduced B cell outgrowth and Ig secretion. IFN-gamma exerted a 7-10-fold more potent antiviral effect than IFN-alpha or -beta. All three types of IFN act directly on B cells. Monocytes and natural killer cells are not necessary for the anti-EBV activity. Of the three recombinant IFN, only IFN-gamma reduced EBV-induced proliferation and Ig secretion when added 3-4 days after virus infection; IFN-alpha/beta were only effective up to 24 h. B lymphoblastoid lines already transformed by EBV are insensitive to the anti-proliferative actions of all three types of IFN. On the basis of these findings, we propose three phases of regulation during EBV infection. In the early phase, EBV-infected cells can be regulated by all IFN. Subsequently, there is an intermediate period where only IFN-gamma is capable of directly affecting EBV-induced B cell responses. In the third phase, B lymphocytes become insensitive to direct actions of all IFN and are now subject to regulation only by cytotoxic cells.