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At least 217 records · Page 12Linked to original sources

Povidone-iodine wash solutions in the prevention of superficial fungal infections; predictive evaluation using the corneofungimetry bioassay.

OBJECTIVE: Prevention of superficial mycoses remains a stubborn problem. The effect of antiseptics for that purpose is largely unknown. We studied the potential fungitoxic activity of povidone iodine (PVP-I) contained in wash solutions. METHODS: The corneofungimetry bioassay was conducted using PVP-I at 1.33%, 2.5%, 4% and 7.5% as test products and four target fungi, namely Candida albicans, Trichophyton rubrum, T. mentagrophytes, var. interdigitale (20 strains) and Microsporum canis. RESULTS: Data show that PVP-I limits fungal growth on stratum corneum. Different species and strains of fungi are not similarly affected. There also exists a diversity of individual susceptibility of the stratum corneum to promote germination of yeasts and arthroconidia.

Anti-Infective Agents, Local↗

Office screening for asymptomatic urinary tract infections. The evaluation of a practical, economic and reliable method screening the urines of asymptomatic girls in a busy pediatric office.

The urines of 3,270 asymptomatic girls were screened at annual physical examinations. The urines were collected in Dixie Cups without prior preparation of the perineum and cultured on 5% sheep cell agar. Less than 2 per cent of the specimens showed significant growth, thus requiring no follow-up visits by 98 per cent of the patients. Slightly less that 1/2 of one per cent were found to have asymptomatic urinary tract infections. The procedure was found to be practical, economically feasible and reliable, and was well accepted by both the parents and patients.

Economics, Medical↗

Expression and diversity of Echinococcus multilocularis AgB genes in secondarily infected mice: evaluating the influence of T-cell immune selection on antigenic variation.

The T-cell-mediated immune response exhibits a crucial function in the control of the intrahepatic proliferation of Echinococcus multilocularis larvae in mice and humans, both being natural intermediate hosts of the parasite. Antigen B (AgB), a metabolized Echinococcus spp. lipoprotein, contributes to the modulation of the T-cell immune response, and distinct sites of the corresponding AgB1, AgB3 and AgB4 genes were shown to be under positive selection pressure. Since several AgB gene variants are present in a single Echinococcus metacestode, we used secondary E. multilocularis infections in BALB/c and in athymic nude mice (devoid of T-cell responses) to analyze the effect of the cellular immune response on the expression and diversity of EmAgB1-EmAgB4 genes. We demonstrated hereby that EmAgB transcripts were less abundant in nude mice during the early phase of infection (at one month post-infection), and that EmAgB2 is simultaneously down-regulated when compared to the other three genes. A negative relationship exists between the level of transcription and diversity of EmAgB genes. Moreover, no excess of non-synonymous substitutions was found among the distinct EmAgB alleles from a single host. Together, these results pointed to the effect of purifying selection, which seemed to eliminate the detrimental AgB variants generated during the development of the metacestode within the peritoneal cavity of its intermediate host.

Animals↗

An experimental model to determine the effects of adjuvant therapy on the incidence of postoperative wound infection: II. Evaluating preoperative chemotherapy.

A study was performed in 110 rats to investigate the effect of an LD50 dose of MTX, rescued with leucovorin treatment in 24 hours, on the ability of surgical wounds to tolerate bacterial contamination. The results of this study would indicate that the optimal time to ensure normal wound healing would be an interval of 10 to 14 days following the administration of large doses of this drug. This information would suggest that the use of methotrexate as a preoperative adjuvant, and radiation therapy following the surgical removal of the tumor, might be a reasonable approach to the adjuvant treatment of head and neck cancer without increasing the risk of wound infections.

Animals↗

Radionuclide imaging in the evaluation of infections and inflammatory disease.

111In leukocyte scintigraphy has high sensitivity and specificity for detecting abdominal and pelvic infections. For abdominal imaging, 111In leukocyte imaging is preferred to 67Ga citrate imaging. If localizing signs are present, CT is the preferred imaging technique. In the lungs, gallium imaging is preferred to leukocyte imaging for identifying active inflammatory processes. Gallium imaging provides quantitative information about inflammatory activity that is not apparent from chest CT scans. Although both gallium and leukocyte imaging have a role in patients with fever of unknown origin, gallium imaging may be preferred because it can be used to detect occult tumor as well as more chronic infectious foci. In patients who have AIDS, gallium imaging is particularly reliable in detecting and monitoring response to therapy of PCP. In febrile AIDS patients without localizing signs, 111In leukocyte scintigraphy is indicated to detect infection, except if PCP is suspected. In patients who have known tumor and fever, 111In leukocyte imaging may be preferred to gallium imaging to identify a source of infection. Most fevers in these patients appear to be due to tumor and chemotherapy, which would not manifest as an area of abnormality on an 111In leukocyte scan. If localizing symptoms are present, CT may be the preferred technique. The major concerns about 111In leukocytes are the hazards associated with withdrawal of blood, handling of blood, and reinjecting labeled cells and the requirement to delay imaging for 18 to 24 hours, thus precluding a rapid result. Potential replacement agents for 111In leukocytes include labeled immunoglobulins and labeled antigranulocyte antibody agents. The three- or four-phase bone scan is the first line diagnostic imaging technique after a plain radiograph in the evaluation of suspected osteomyelitis. If the bone scan is inconclusive, 111In leukocytes are the second line diagnostic imaging technique, particularly in adults with other bony abnormalities such as degenerative bone changes or trauma. Gallium imaging also may be used, preferably if other bony abnormalities are absent. In children, gallium imaging is the second line diagnostic imaging technique. Once the diagnosis has been made, gallium may be the preferred technique for following response to therapy.

Animals↗

HIV-1 biological phenotype in long-term infected individuals evaluated with an MT-2 cocultivation assay.

OBJECTIVE: We have previously demonstrated that detection of syncytium-inducing (SI) HIV-1 in asymptomatic seropositive individuals is associated with rapid progression to AIDS. In the present study, we sought to develop and evaluate an HIV-1 phenotyping assay for the screening of large numbers of individuals. METHODS: Efficiency of HIV-1 isolation from patient peripheral blood mononuclear cells (PBMC) was studied with donor PBMC or seven different CD4+ T-cell lines as target cells. The biological phenotype of sequential isolates from 20 long-term asymptomatic HIV-1-seropositive individuals was determined by two different assays. RESULTS: Non-SI isolates, efficiently recovered by cocultivation with donor PBMC, were never isolated with T-cell lines as target cells. Direct cocultivation with MT-2 cells, but not with six other CD4+ T-cells, resulted in the efficient recovery of SI isolates. HIV-1 MT-2 tropism and SI capacity were shown to be coupled properties at the clonal level. SI isolates emerged in 10 out of 20 longitudinally-studied individuals. In these long-term infected individuals, appearance of SI isolates was associated with progression to AIDS. CONCLUSIONS: Direct cocultivation of patient PBMC with the MT-2 cell line is a sensitive, specific and convenient method to detect SI isolates. The availability of an assay suitable for the screening of large groups allows further study of the value of HIV-1 biological phenotyping as a prognostic marker.

Acquired Immunodeficiency Syndrome↗

The duration of zidovudine benefit in persons with asymptomatic HIV infection. Prolonged evaluation of protocol 019 of the AIDS Clinical Trials Group.

OBJECTIVE: To determine the durability of zidovudine-induced delay in clinical progression of asymptomatic human immunodeficiency virus (HIV) disease and to assess the relationship between this effect and the entry CD4+ cell count. DESIGN AND INTERVENTIONS: Extended follow-up data from subjects participating in protocol 019 of the AIDS [acquired immunodeficiency syndrome] Clinical Trials Group were examined. Subjects were offered a total daily dose of 500 mg of open-label zidovudine after the unblinding of the original randomized trial in 1989. Original treatment groups included placebo, 500 mg of zidovudine, or 1500 mg of zidovudine daily in divided doses. Three distinct analyses were conducted to assess the duration of zidovudine's effect on progression to AIDS or death: (1) analysis of all follow-up information from all subjects, (2) analysis of all subjects but with follow-up of original placebo-assigned subjects censored at the time open-label zidovudine was initiated, and (3) analysis of the effect of initiating zidovudine in subjects initially assigned to receive placebo. SETTING: University-based and university-affiliated AIDS research clinics participating in AIDS Clinical Trials Group protocol 019. PATIENTS: A total of 1565 asymptomatic HIV-infected subjects with entry CD4+ cell counts less than 0.50 x 10(9)/L (500/microL). MAIN OUTCOME MEASURE: Time to progression to AIDS or death. RESULTS: During follow-up of up to 4.5 years (mean, 2.6 years), 232 subjects progressed to AIDS or died. In each of the three analyses described herein, zidovudine was associated with a significant (P = .008, .004, .007) decrease in the risk of such progression. However, each of these analyses also indicated a decreasing placebo:zidovudine relative risk with duration of use (P = .002, .08, .04), suggesting a nonpermanent effect. The duration of benefit appeared to be related to entry CD4+ cell count, with greater benefit in those with higher counts at entry. No significant differences in survival were found between those originally randomized to zidovudine or placebo. CONCLUSIONS: Zidovudine at 500 mg/d caused a significant delay in progression to AIDS or death, but its earlier use in asymptomatic disease was not associated with an additional prolongation of survival compared with delayed initiation. The delay in progression diminished over time especially in subjects with entry CD4+ cell counts less than 0.30 x 10(9)/L (300/microL). Treatment strategies that alter drug regimens before the loss of zidovudine benefit should be explored.

Acquired Immunodeficiency Syndrome↗

Epidemiology of viral infections and evaluation of the potential benefit of OM-85 BV on the virologic status of children attending day-care centers.

Viral investigations were performed during 4 winter seasons (88/89, 89/90, 92/93, 93/94) in children attending day-care centers (DCCs) in the Rhône Département in eastern France. Over the total observation period of 4 winter seasons, 780 children were screened with a nasal swab for the presence of viruses. Of those, 230 (29.5%) had a positive viral culture. The viruses identified were respiratory syncytial virus (RSV), influenza A and B virus, parainfluenza virus, coronavirus, rhinovirus, adenovirus and enterovirus. During that time, 83 epidemic events in 47 DCC were recorded. A particular virus was judged to be causally related to an epidemic if the identical virus was isolated in > or = 3 children during the same outbreak of respiratory diseases. Thus, in 51 cases (61.4%) of all epidemics, the following viruses were responsible for an epidemic: RSV (n = 23), coronavirus (n = 10) (only during the season of 1993-1994), influenza A virus (n = 6), rhinovirus (n = 4), enterovirus (n = 4), adenovirus (n = 3) and parainfluenza virus (n = 1). Except for the somewhat surprising accumulation of coronavirus epidemics during the winter of 1993-1994, there were only minor seasonal variations from one year to another. As expected, RSV accounted for about one third of all respiratory tract infections in children attending DCCs and was therefore the most important single causative agent. These results are compared with data from children who did not attend a DCC and were cared for in a private practice.(ABSTRACT TRUNCATED AT 250 WORDS)

Adjuvants, Immunologic↗

Delavirdine in combination with zidovudine in treatment of human immunodeficiency virus type 1-infected patients: evaluation of efficacy and emergence of viral resistance in a randomized, comparative phase III trial. The M/3331/0013B Study Group.

We compared the activity of delavirdine (DLV) plus zidovudine (AZT) (n = 300) with that of AZT (n = 297) against human immunodeficiency virus type 1 in a randomized, double-blind, placebo-controlled trial. DLV exerted a transient antiviral effect, and mutations for resistance to DLV were found in more than 90% of subjects at week 12. The K103N mutation, which confers nonnucleoside reverse transcriptase inhibitor cross-resistance, was found in 85% of the patients.

Anti-HIV Agents↗

Human genital papilloma infections: an evaluation of immunologic competence in the genital neoplasia-papilloma syndrome.

Immunologic evaluations of women with genital neoplasia-papilloma syndrome demonstrated the presence of subclinical immunodeficiency when compared with results in 20 control women. All patients with genital neoplasia-papilloma syndrome were previously found to have human papillomavirus deoxyribonucleic acid in genital neoplasias or papillomas occurring either synchronously (in at least two genital organs at the same time) or metachronously (at different times during a period of months to years). Immunologic tests included blastogenic responses of lymphocytes to mitogens (phytohemagglutinin, concanavalin A, pokeweed mitogen, and tetanus antigen) and lymphocyte phenotyping with the use of monoclonal antibodies (OKT3, OKT4, OKT8, and OKT11). As compared with those of control subjects, the responses of the lymphocytes of patients with genital neoplasia-papilloma syndrome to mitogens were significantly decreased. The group with genital neoplasia-papilloma syndrome had a significantly higher percentage of suppressor-cytotoxic T cells (OKT8-positive cells) when compared with that of control subjects (mean 33% versus 18%) and a lower proportion of helper T cells (OKT4-positive cells) when compared with that of control subjects (35% versus 50%). The mean helper-to-suppressor/cytotoxic T-cell ratio (mean OKT4/OKT8 ratio) in the human papillomavirus-infected women was 1.72 +/- 0.29 (SE) as compared with 3.21 +/- 0.33 (SE) in the control group, demonstrating a significant reduction of the ratio in the patients with genital neoplasia-papilloma syndrome. These findings suggest that patients with genital neoplasia-papilloma syndrome have a reduced suppressor/cytotoxic T-cell ratio (mean OKT4/OKT8 ratio; that in the human papillomavirus-infected women was 1.72 +/- 0.29 (SE) as compared with 3.21 +/- 0.33 (SE) in the control group, demonstrating a significant reduction of the ratio in patients with genital neoplasia-papilloma syndrome. These findings suggest that patients with genital neoplasia-papilloma syndrome have reduced immunocompetence of unknown etiology.

Adolescent↗

Serodiagnosis of Helicobacter pylori infection: an evaluation of a commercially available ELISA-IgG.

BACKGROUND: Our aim was to evaluate a commercially available ELISA (Pyloriset IgG, Orion diagnostica, Imphos B.V.) for detection of serum IgG antibodies to Helicobacter pylori. METHODS: Serum samples were taken from 154 Dutch patients. As a reference method several biopsy specimens were taken from different gastric areas for histological analysis, bacterial culture and direct urease testing. The sensitivity, specificity, positive and negative predictive values of the Pyloriset IgG were calculated as compared to the reference method. RESULTS: Of 154 patients 126 were found to be H. pylori positive (82%), 28 were H. pylori negative (18%). Using a cut-off value at a titre of 500 U/l (as advised by the manufacturer) we found a sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) of 81, 89, 97 and 51%, respectively. Lowering the cut-off value to 350 U/l and excluding patients aged above 70 years optimalized the performance of the Pyloriset IgG to a sensitivity, specificity, PPV and NPV of 92, 96, 99 and 72%, respectively. In the subgroup of 54 patients under the age of 45 years a sensitivity, specificity, PPV and NPV of 92, 100, 100 and 82% was found. CONCLUSIONS: The Pyloriset IgG is a simple and accurate method for detecting H. pylori infection in dyspeptic Dutch patients. The performance of this assay is improved by lowering the cut-off value (test becomes predominantly more sensitive) and excluding older patients (test becomes predominantly more specific). Therefore serology might eventually replace endoscopy or breath tests in the detection of H. pylori infection, especially in the younger age groups.

Adolescent↗

Evaluation of infection parameters in the production of replication-defective HSV-1 viral vectors.

Herpes simplex virus type-1 (HSV-1) is a neurotrophic human pathogen that establishes life-long latency in the nervous system. Our laboratory has extensively engineered this virus to retain the ability to persist in neurons without expression of lytic genes or disease phenotype. Highly defective, replication-incompetent HSV mutants are thus potentially ideal for transfer of therapeutic transgenes to human nerves where long-term therapy of nervous system disease may be provided. A prerequisite for using recombinant HSV vectors for therapeutic gene delivery to humans is the development of methods for large-scale manufacture of HSV vectors. Here we report studies to identify infection parameters that result in high-yield production of immediate early gene deletion mutant HSV vectors in complementing cells that supply the deleted essential viral functions in trans. Virus yield was correlated with various culture media conditions that included pH, glucose metabolism, and serum levels. The results demonstrated that systematic media exchange to remove lactate derived from high-level glucose consumption, maintenance of tissue culture pH at 6.8, and the use of 5% fetal bovine serum gave the highest yield of infectious virus. The data indicate that these are important parameters to consider for high-yield, large-scale virus production.

Animals↗

In vivo ovine flap model to evaluate surgical infection and tissue necrosis.

Although the inciting causes and the end results of soft tissue infection are well described, we have not achieved a quantitative methodistic description of the sequence of events in between. The following study presents an isolated in vivo model which will allow specific manipulations and quantifications of the events of integumentary infection. Pedicle flaps were raised on the buttock of the adult range ewe and it was multiply inoculated with Staphylococcus aureus, and followed for 96 hr. This pedicle contains not only a well-defined artery, vein, and nerve, but also a well-developed efferent lymphatic vessel. In addition, the distal portion of the flap is primarily supplied by a musculocutaneous arterial perforator, making the distal flap a watershed area. Anatomic, radiologic, and vital stain injection studies confirmed these results. The sheep model was found to be superior to the pig model both in terms of its anatomy (the addition of an efferent lymphatic vessel) as well as the disposition of the sheep which was more compliant than that of the pig. We believe that this flap will allow multiple manipulations and provide an in vivo isolated system to study the pathobiology of soft tissue infection.

Animals↗

Evaluation of infection and treatment methods in immunization of improved cattle against theileriosis in an endemic area of Kenya.

Five experiments were carried out to determine the efficacy of immunization against theileriosis in an endemic area of Kenya using artificial infection with a mixture of stabilates of Theileria parva stock or natural infection and treatment with parvaquone or several formulations of oxytetracyclines. For the first four experiments, introduced, susceptible Sahiwal/Friesian crosses were used and in the fifth, calves of Boran/Maasai zebu crosses born on the site. Cattle were infected either artificially with sporozoite stabilates of local isolates of T. parva parva derived from cattle and T. parva lawrencei derived from African buffalo or exposed to natural tick challenge on the ranch mostly derived from buffalo. The cattle were then given various treatment regimens using either parvaquone or long- and short-acting formulations of oxytetracycline. Treatment of natural infections, although it can be effective, was not considered a practical method on a large scale because of the need for intensive monitoring in the case of parvaquone treatment and the possibility of cattle not becoming infected in the case of prolonged application of long-acting formulations of oxytetracycline. Both methods were relatively expensive. Artificial infection treatment proved more practical and methods were developed where the monitoring of cattle was not required during the immunization procedure. Out of a total of 16 drug regimens investigated, one (consisting of two treatments of a short-acting formulation of oxytetracycline at 10 mg kg-1 body weight on Days 0 and 3 or 4 after infection) was found to be the most efficacious and the cheapest, and has now been used on a routine basis. This method can be used successfully on calves greater than 1 month of age.

Animals↗