Minimum inhibitory concentration (MIC) versus minimum biofilm eliminating concentration (MBEC) in evaluation of antibiotic sensitivity of gram-negative bacilli causing peritonitis.

OBJECTIVE: Minimum inhibitory concentration (MIC) and minimum biofilm eliminating concentration (MBEC) results were compared to determine changes in the pattern of antibiotic sensitivity of gram-negative bacilli from the planktonic to the biofilm phase of growth. METHODOLOGY: The MIC and MBEC assays were conducted on stored isolates obtained from patients presenting with peritoneal dialysis-related gram-negative peritonitis with Escherichia coli or Pseudomonas. RESULTS: The antibiotic sensitivities of planktonic organisms tested by the MIC assays were significantly higher than the antibiotic sensitivities of the same organisms in their biofilm state, as tested by the MBEC assays. CONCLUSIONS: In their biofilm state, gram-negative bacteria are much less susceptible to antibiotics compared to their antibiotic susceptibility in the planktonic state.     

Cytotoxicity, Accumulation, and Efflux of Cisplatin and Its Metabolites in Human Ovarian Carcinoma Cells

Cisplatin (CP) is one of the most useful antineoplastic drugs. When CP is dissolved in human plasma, different metabolites are formed. Using the OV 2008 human ovarian cancer cell line, we examined the relative cytotoxicities of CP and its metabolites (aquated CP [AP], monomethionine CP [MP], bismethionine CP [BP], and a mixture of CP metabolites in ultrafiltrated human plasma [UP])in vitro.By clonogenic assay, cell survival (percent of mean ± SE) of OV 2008 cells exposed for 1 hr to 6.7 μ of CP was 9.8 ± 0.7 and for its equal platinum contents of AP, MP, BP, and UP solutions were 3.3 ± 0.7, 9.8 ± 0.9, 15.9 ± 1.1, 76.8 ± 2.1, and 13.1 ± 0.7, respectively. AP was the most cytotoxic species, and BP was the least cytotoxic species. Cellular platinum uptake (ng/10⁶cells) after addition of 0.33, 1.6, and 2.5 m of each species for 1 hr was measured and a strong correlation was found between cytotoxicity of each CP metabolite and its corresponding cellular platinum (Pt) uptake (r= 0.997). There was a strong correlation between cytotoxicity of the CP metabolites and their DNA binding. With fractionation of these cells into DNA, nucleoplasm and cytoplasm, the highest platinum content was found on DNA. The most important factor that seems to be responsible for the cytotoxicities of the different CP metabolites is the amount of their associated intracellular accumulation, and particularly the degree of their binding to DNA.     

Time-related patterns of ventricular shunt failure

Proximal obstruction is reported to be the most common cause of ventriculoperitoneal (VP) shunt failure, suggesting that imperfect ventricular catheter placement and inadequate valve mechanisms are major causes. This study retrospectively examined patterns of shunt failure in 128 consecutive patients with symptoms of shunt malfunction over a 2-year period. Factors analyzed included site of failure, time from shunt placement or last revision to failure, age of patient at time of failure, infections, and primary etiology of the hydrocephalus. One hundred of these patients required revisions; 14 revisions were due to infections. In this series there was a higher incidence of distal (43%) than of proximal (35%) failure. The difference was not statistically significant when the overall series was considered; however, when factoring time to failure as a variable, marked differences were noted regardless of the underlying cause of hydrocephalus or the age of the patient. Of the 49 patients needing a shunt revision or replacement within 2 years of the previous operation, 50% had proximal malfunction, 14% distal, and 10% had malfunctions attributable directly to the valve itself. Also, 12 of the 14 infections occurred during this time interval. In sharp contrast, of the 51 patients having shunt failure from 2 to more than 12 years after the previous procedure, 72% had distal malfunction, 21% proximal, and only 6% had a faulty valve or infection. This difference between time to failure for proximal versus distal failures was statistically significant (P<0.00001 for both Student's t-test and non-parametric Mann-Whitney U-test). It is concluded that these data are valuable for interpreting outcome studies of novel valve systems and ventricular catheter placement techniques, by defining a time frame during which these modifications can be reliably evaluated.Presented at the Annual Scientific Meeting of the American Association of Neurological Surgeons, San Diego, Calif., 9–14 April 1994     

In vitro and in vivo assays on egg white/polyvinyl alcohol/clay nanocomposite hydrogel wound dressings

Novel nanocomposite hydrogel wound dressings on the basis of egg white and polyvinyl alcohol, as matrix, and natural Na-montmorillonite clay, as reinforcing agent, were prepared and their performances on wound healing investigated in vitro and in vivo. In vitro cytotoxicity assay revealed non-cytotoxic activity and excellent biocompatibility level of prepared nanocomposite hydrogel wound dressings. The bacterial penetration assay showed the prepared nanocomposite hydrogel wound dressings are excellent barriers against microorganisms and could protect the wound from infection during the wound healing. In vivo animal study showed that the wound healing process was considerably faster in wounds covered with nanocomposite hydrogel wound dressings compared to the conventional wound dressing, i.e. sterile gauze, due to creation of a moist environment on the wound surface and faster migration rate of the epidermal cells. The mechanical properties of healed wounds with nanocomposite hydrogel wound dressings were better than those control wounds covered with sterile gauze due to their better collagen formation ability as a result of created moist healing condition as well as the presence of egg white, as a source of proteins, in their structures.     

The role of microRNAs in respiratory viral infection: friend or foe?

MicroRNAs (miRNAs) have emerged as a class of regulatory RNAs in host–pathogen interactions. Aberrant miRNA expression seems to play a central role in the pathology of several respiratory viruses, promoting development and progression of infection. miRNAs may thus serve as therapeutic and prognostic factors for respiratory viral infectious disease caused by a variety of agents. We present a comprehensive review of recent findings related to the role of miRNAs in different respiratory viral infections and discuss possible therapeutic opportunities aiming to attenuate the burden of viral infections. Our review supports the emerging concept that cellular and viral‐encoded miRNAs might be broadly implicated in human respiratory viral infections, with either positive or negative effects on virus life cycle. Copyright © 2016 John Wiley & Sons, Ltd.     

The association between nuchal nevus flammeus and alopecia areata: a case-control study

BACKGROUND: The association of alopecia areata (AA) with nuchal nevus flammeus (NNF) has been demonstrated by previous studies. OBJECTIVES: The aim of this study was to investigate whether AA is associated with NNF. Methods: 199 AA patients and 215 controls without AA were examined for the presence of NNF. RESULTS: 35 patients (17.6%) in the AA group had NNF. In the control group, 20 patients (9.3%) had NNF (odds ratio = 2.08, 95% confidence interval 1.43-2.73; p = 0.013). A statistically significant association was found between the presence of NNF and duration of the AA (p < 0.001). The presence of NNF was associated with severity of AA (p < 0.001). CONCLUSIONS: The results of our study suggest a link between NNF and AA especially in severer and more chronic forms.