Factors influencing the trailing endpoint observed in Candida albicans susceptibility testing using the CLSI procedure.

The trailing endpoint phenotype observed during testing of Candida albicans susceptibility to azoles according to the CLSI procedure is defined as a difference in MIC depending on whether the result is obtained after 24 or 48 h. This study investigated whether intrinsic differences between the EUCAST and CLSI methods could explain trailing growth. The glucose concentration in the medium and the shape of the microtitre plate wells were both found to be involved. In order to reduce the incidence of trailing growth according to the CLSI procedure, the use of higher glucose concentrations and flat-bottomed microtitre plates could be valuable improvements.     

Factors influencing HIV-1 banding patterns in miniaturized western blot testing of dried blood spot specimens.

In the HIV Seroprevalence Survey among Childbearing Women (SCBW), antibodies to human immunodeficiency virus type 1 are detected using enzyme immunoassays (EIA) and Western blot (WB) methods modified to accommodate samples of blood dried on special collection paper. Dried blood spot (DBS) eluates positive by EIA are tested by one of two WB methods, the miniblot technique using equipment from Immunetics Corporation and the PBS Integra assay (pageblot) from Genetic Systems. In this report we compared the performance of the two WB methods. The identity and position of the viral proteins on the WB were identified using monoclonal antibodies and monospecific antisera. The blots differed substantially in their composition and concentration of viral glycoproteins. Performance of the WB assays with DBS elution buffers from different EIA kits was equivalent except for samples eluted in the Abbott buffer, which reduced detection of antibodies to the p31, p51, p55, and p66 viral proteins. Case classification of DBS, positive sera, dilution curve samples, and seroconversion panels was equivalent by both tests in the presence of all elution buffers. Proficiency evaluation panels sent to SCBW participating laboratories over a 3-year period were used to note the differences between the two WB methods in detection of antibodies to the viral glycoproteins.     

Canine ehrlichiosis in Connecticut.

The first case of canine ehrlichiosis in Connecticut is reported. A female Brittany spaniel from Milford presented with lethargy, anorexia, fever, petechiae, splenomegaly, thrombocytopenia, anemia, elevated serum alkaline phosphatase, lymphopenia, and hypoalbuminemia. Serologic analysis revealed antibodies to Ehrlichia canis (titer, 1:2,560). This documents a more northern geographic distribution in the United States for this infectious agent than had previously been suspected.     

Factors influencing bacterial adherence to biomaterials.

The adherence of bacteria to implanted medical devices is believed to be important in the development of implant associated infections. Measures which reduce bacterial adherence should reduce the incidence of these infections. However, in order to assess the importance of adherence, the effectiveness of methods to reduce adherence, and compare data from different laboratories, the conditions of the in vitro studies on adherence need to be specified. There are currently no correct and incorrect methods, however, methods used need to be carefully described. The studies reported here indicate that the definition of adherence needs to be established, with the use of polystyrene as the reference material recommended. Since the adherent organisms lose adherence traits with culture, cultures must be selected for adherence regularly. It is important to control the number of organisms/ml but the volume used is not important. The medium used to grow the organisms and the use of stationary, rocking or flow conditions will alter adherence and need to be specified and be consistent within a set of experiments. Culture conditions, methods of rinsing the material, methods of elution and counting, or direct counting of organisms on the material need to be specified. Finally, as much information as possible on the bulk and surface properties of the material should be provided. The handling of the material for the experiments should be careful and defined. Fingerprints, contact with protein, wet surfaces vs dry surfaces, etc., will all affect the subsequent adherence. The materials should not be re-used since the removal of the adherent proteins or the biofilm is very difficult. Progress can be made in this important area if the details of procedures are specified.     

Factors influencing children to self-disclose sexual abuse.

Self-disclosure by victims of child sexual abuse (CSA) is critical to initiate legal and therapeutic intervention. Unfortunately, research indicates that lengthy delays in disclosure and even nondisclosure are common. A comprehensive review of the clinical and research literature on CSA and an overview of related bodies of literature was conducted. Areas addressed include the context of sexual abuse as it relates to disclosure, the context and elements of children's disclosures, motivational factors inhibiting disclosure, and models of the disclosure process. Ancillary and analogue research on secrecy and disclosure are also reviewed. Implications for future research and practice are discussed.     

Phage-typing of coagulase-negative staphylococci. Factors influencing typability

Factors influencing the phage-typability of coagulase-negative Micrococcaceae have been studied in 2,778 clinical isolates comprising A) 209 consecutive isolates from one laboratory, B) 2,107 clinical strains submitted for phage-typing for epidemiological reasons, and C) 462 strains representing all isolates of presumed clinical significance found in two laboratories during one month. The reproducibility was acceptable at duplicate repeated typing of the same strains as well as by typing epidemiologically-related pairs of strains from the same patient. Strains of Staphylococcus haemolyticus were seldom typable, whereas strains of S. epidermidis and S. hominis had a higher typability. Methicillin-resistant strains and other multiple-resistant strains were rarely typable (11-13%). The typability was higher among susceptible strains (36%) and strains resistant to penicillin only (43-50%). The typability of strains of the same species and antibiotic-resistance pattern differed between hospitals compared and decreased markedly over the years for multiple-resistant S. epidermidis isolates.     

Factors influencing quantitative isolation of varicella-zoster virus.

Optimal conditions are described for the recovery of cell culture-derived varicella-zoster virus (VZV). Of the cells tested, human embryonic lung fibroblasts were the most sensitive. Storage and handling procedures were examined to determine the stability of VZV in viral transport medium. When the initial VZV titer was high (2 X 10(4) PFU/ml) 40% of the VZV survived room temperature for 24 h and 75% of the VZV remained viable for this long at 4 degrees C. Recovery was 5- to 10-fold less at lower initial VZV titers (less than 2 X 10(3) PFU/ml). Other factors which influenced VZV recovery included freezing at -20 degrees C, the use of cotton or calcium alginate swabs, and filtration to remove bacterial contaminants. The tissue culture methods described were used in a reconstruction experiment to demonstrate that VZV could be recovered from a laboratory coat or human skin (0.1 to 0.3% of input VZV) or from a stethoscope (19% of input VZV) as late as 30 min after inoculation. During a clinical trial using optimal VZV recovery procedures, 76% of the patients with herpes zoster yielded VZV when first cultured, and 60% remained culture positive for an additional 48 h.     

Factors influencing detection of quantitative cytomegalovirus antigenemia.

Of 20 blood specimens testing positive for cytomegalovirus antigen after immediate processing, 19 (95%) remained positive when kept at room temperature for 24 h before processing. Quantitative antigenemia decreased by an average of 44% after storage. Compared with acetone fixation, formaldehyde fixation showed improved readability, fewer artifacts, and a higher degree of sensitivity.     

Factors influencing heat-labile Escherichia coli enterotoxin activity.

In this study, conditions for production, detection, and storage of heat-labile Escherichia coli enterotoxin (LT) in culture filtrates from E. coli H-10407 were defined by using the adrenal tumor cell assay system. An enriched medium containing 0.6% yeast extract, 2% Casamino Acids, and 0.25% glucose buffered at pH 8.5 produced the highest LT activity of the various test media. In E. coli strain H-10407, LT activity was markedly decreased if the initial pH of the culture media was reduced to pH 7.5 or less. In contrast to E. coli P-263, if strain H-10407 was grown in the presence of mitomycin C there was no increase in LT production. Crude-culture filtrates containing LT can be stored at 4 degrees C for several days without an appreciable loss of activity; however, for long-term storage lyophilization or freezing at -70 degrees C is recommended.     

Factors influencing 133-xenon washout in a nose-sinus model.

The 133-xenon washout technique is a non-invasive method for the evaluation of ventilation of the paranasal sinuses. The half-time of 133-xenon washout (T(1/2)) is considered to reflect sinus ostial function and sinus ventilation. However, it is not known how morphological and physiological factors affect the washout from the paranasal sinuses. The aim of the present study was to evaluate how sinus volume, ostial diameter and nasal ventilation influence 133-xenon washout in a nose-sinus model. This is important for the interpretation of measurements of 133-xenon washout from paranasal sinuses in healthy subjects and in subjects with sinus disease. The 133-xenon washout was measured with a scintillation camera. The statistical analysis of the results showed that the logarithm (to the base 10) of the half-time of 133-xenon washout is linearly related to the ostial diameter, the sinus volume and the nasal ventilation in the model. In a multiple linear regression model, the most important factor contributing to 133-xenon washout was found to be the ostial diameter, which explained 76% of the variation in log T(1/2). In the same statistical model the sinus volume explained 7.5% and the ventilation 5.3% of the variation in log T(1/2). Calculations of the functional ostial diameter in healthy subjects were made, based on the results of the model study. The mean functional ostial diameter was found to be 3.5 mm (range 0.5-7.5 mm). The results obtained with the present model experiments may be of importance for the correct interpretation of the results of measurements of 133-xenon washout in healthy subjects and patients.     

Genetic information leaflets: influencing attitudes towards genetic testing.

PURPOSE: This article explores how a "neutral" genetics information leaflet influenced people's attitudes to be more positive toward predictive genetic testing. This is of concern, given the desire within clinical genetics and population based testing to provide information that informs choice without directing toward, or against, testing. METHOD: Four studies are reported. The first two investigated presentation (glossy and colored vs. black and white), and method of reading (read only vs. read followed by probing questions). The second two investigated content, using "think aloud," "card sort," and delayed recall tasks. RESULTS: Those receiving a glossy leaflet expressed more positive attitudes and more interest in undergoing testing than those receiving a black and white leaflet, and those who were asked questions about what they had read were more positive about genetic testing than those who only read the leaflet. Recall one week later varied from 72% to 28%, depending on type of information. Information that described the advantages of genetic testing or discussed genes and genetic testing in relation to disease were well recalled and rated positively. Attitudes toward information ranged from 100% positive (e.g., what diseases genetic tests are available for) to 0% positive (e.g., the meaning of a positive result). CONCLUSION: These results show that quite small changes within a leaflet can change attitudes toward genetic testing. This is of concern, given the association between attitudes toward a behavior and undergoing that behavior. The form, method of presentation, and content of genetic information leaflets should be evaluated for impact on attitude and decisions before they are used clinically.     

Factors influencing left ventricular shortening in isolated canine heart.

To assess in the intact ventricle the steady-state influence of several mechanical variables on the extent of left ventricular midwall circumferential shortening, a pressure servo system was utilized in isolated canine hearts. The system permits continuous monitoring of ventricular volume and control of diastolic and systolic pressures. After determination of the diastolic volume at zero filling pressure (V0), a series of variably preloaded or afterloaded contractions were generated including the isovolumic state. Contractile state was manipulated in a positive (calcium, 12-18 mg/100 ml; norepinephrine, 0.4-1.4 mug/min) or negative (propranolol, 0.12-0.50 mg/min) direction. Force and length terms derived for a thick-walled sphere were expressed per cross-sectional area of muscle and length, respectively, calculated at V0. For any preload, an inverse linear (r greater than 0.96) force-shortening relation was obtained, and each line was identified by its slope and isovolumic load (sigma0). Both slope and sigma0 increased with positive inotropic agents (vis-a-vis propranolol) or increments in preload. Thus, in the intact ventricle an inverse linear relation characterizes the force-shortening relation with the amount of shortening determined by initial fiber length, afterload, and the contractile state of the myocardium.     

Factors influencing public participation in biobanking

A diversity of public participation in biobanking is a highlight for the success of biobanks. It was previously reported that only two-thirds of Jordanians expressed interest in biobanking. To promote public involvement in a biobank, it is imperative to determine the aspects that influence the decision-making to participate. On the basis of a national survey involving 3196 respondents, the influence of 13 biobanking factors was assessed, including returning research results, privacy, freedom of choice, uncertainties about research, monetary and health considerations, and personal belief. Perception toward each factor was also correlated with willingness to participate in a biobank. A considerable number of respondents indicated returning research results as influential in their decision to become biobank donors. Interestingly, whereas the positive perception of availability of general results (39%) correlated with willingness to donate for biobanking, the negative view of unavailability of individualized results (47%) did not correlate with unwillingness. Religious permission of sample donation for research had the strongest positive influence (61%) and the highest correlation to participate among positively perceived factors. Unspecified research was highly indicated as a negative factor (45%), but did not correlate with unwillingness to become a biobank donor, whereas allowed withdrawal had a positive effect (31%) and correlation to contribute to biobanking. The negative perception of accessing medical information (9.5%) and re-contact (8.5%) had the strongest correlation with unwillingness to donate to a biobank. These results may provide an insight into how to formulate strategies to promote public participation in biomedical research and biobanking.     

Factors influencing Stroop performance in schizophrenia

Recent studies suggest that individuals with schizophrenia show enhanced facilitation but similar interference in reaction times (RTs), compared with control participants, combined with increased error interference. This study examined the relationship between errors and RTs on the Stroop task among individuals with schizophrenia. The authors examined performance on a speeded Stroop task, designed to increase errors, in 29 individuals with schizophrenia and 29 nonpatient control participants. The authors also analyzed color-naming and word-reading estimates from process dissociation analyses. The findings suggest that a lack of increased RT interference among patients (compared with control participants) is not solely due to the increased number of errors they produce in the incongruent condition but is also influenced by a greater impact of the word even in the neutral condition.