Gram staining of protected pulmonary specimens in the early diagnosis of ventilator-associated pneumonia. (9/357)

We evaluated prospectively the use of Gram staining of protected pulmonary specimens to allow the early diagnosis of ventilator-associated pneumonia (VAP), compared with the use of 60 bronchoscopic protected specimen brushes (PSB) and 126 blinded plugged telescopic catheters (PTC) obtained from 134 patients. Gram stains were from Cytospin slides; they were studied for the presence of microorganisms in 10 and 50 fields by two independent observers and classified according to their Gram stain morphology. Quantitative cultures were performed after serial dilution and plating on appropriate culture medium. A final diagnosis of VAP, based on a culture of > or = 10(3) c.f.u. ml-1, was established after 81 (44%) samplings. When 10 fields were analysed, a strong relationship was found between the presence of bacteria on Gram staining and the final diagnosis of VAP (for PSB and PTC respectively: sensitivity 74 and 81%, specificity 94 and 100%, positive predictive value 91 and 100%, negative predictive value 82 and 88%). The correlation was less when we compared the morphology of microorganisms observed on Gram staining with those of bacteria obtained from quantitative cultures (for PSB and PTC respectively: sensitivity 54 and 69%, specificity 86 and 89%, positive predictive value 72 and 78%, negative predictive value 74 and 84%). Increasing the number of fields read to 50 was associated with a slight decrease in specificity and positive predictive value of Gram staining, but with a small increase in its sensitivity and negative predictive value. The results obtained by the two observers were similar to each other for both numbers of fields analysed. Gram staining of protected pulmonary specimens performed on 10 fields predicted the presence of VAP and partially identified (using Gram stain morphology) the microorganisms growing at significant concentrations, and could help in the early choice of the treatment of VAP. Increasing the number of fields read or having the Gram stain analysed by two independent individuals did not improve the results.  (+info)

Influence of pentoxifylline, A-802710, propentofylline and A-802715 (Hoechst) on the expression of cell cycle blocks and S-phase content after irradiation damage. (10/357)

The toxicity of the five methylxanthine derivatives, caffeine, pentoxifylline, A802710, propentofylline and A802715, was determined against the two human melanoma lines, Be11 and MeWo, and against the two human squamous cell carcinoma lines, 4197 and 4451, by vital dye staining assay. Pentoxifylline and A802710 emerge as the least toxic showing TD(50) (toxic dose of 50%) levels of 3.0-4.0 mM. Propentofylline and caffeine take an intermediate position. A802715 has a TD(50) of 0.9-1.1 mM and is the most toxic. Subtoxic concentrations (+info)

Biological characterization of Trypanosoma cruzi strains. (11/357)

Biological parameters of five Trypanosoma cruzi strains from different sources were determined in order to know the laboratory behaviour of natural populations. The parameters evaluated were growth kinetics of epimastigotes, differentiation into metacyclic forms, infectivity in mammalian cells grown in vitro and parasite susceptibility to nifurtimox, benznidazole and gentian violet. Differences in transformation to metacyclic, in the percentage of infected cells as well as in the number of amastigotes per cell were observed among the strains. Regarding to pharmacological assays, Y strain was the most sensitive to the three assayed compounds. These data demonstrate the heterogeneity of natural populations of T. cruzi, the only responsible of infection in humans.  (+info)

Endocervical Gram stain smears and their usefulness in the diagnosis of Chlamydia trachomatis. (12/357)

OBJECTIVE: To evaluate the usefulness of endocervical Gram stain smears in the diagnosis of Chlamydia trachomatis and Neisseria gonorrhoeae in a female population attending a STD clinic. METHODS: 494 females attending a STD clinic and undergoing a speculum examination had endocervical specimens submitted for C trachomatis culture, direct fluorescent antibody testing (DFA), and N gonorrhoeae culture. Endocervical smears were also collected for Gram stain. The number of polymorphonuclear leucocytes (PMN) per high power field (HPF), presence of bacteria, yeast, red blood cells, and clue cells were recorded. Clinical signs of cervicitis were also documented. RESULTS: N gonorrhoeae was isolated from one subject who was co-infected with C trachomatis and no further analysis was done regarding N gonorrhoeae. Analysis was performed on 220 participants. The prevalence of C trachomatis infection was 13%. Of the Gram smears collected, 55% were inadequate owing to the presence of vaginal contamination. There were an equal number of C trachomatis isolates in patients with < or = 10 PMN/HPF (48%) and > 10 PMN/HPF (52%). Endocervical mucopus and erythema were statistically significant for the presence of C trachomatis (p < 0.001 and 0.02 respectively). The presence of any signs of cervicitis-that is, mucopus, friability, erythema, and ectropion together with > 10 PMN/HPF was statistically significant for the presence of C trachomatis. CONCLUSION: The use of endocervical Gram smear results together with clinical information can be used to identify high risk women for C trachomatis infection.  (+info)

A multicenter study of bacterial vaginosis in women with or at risk for human immunodeficiency virus infection. (13/357)

BACKGROUND: Bacterial vaginosis is a common gynecologic infection that has been associated with a variety of gynecologic and obstetric complications, including pelvic inflammatory disease, postabortal infection and premature delivery. Recent studies suggest that bacterial vaginosis may increase a woman's risk for human immunodeficiency virus (HIV). We undertook this study to assess whether the prevalence and characteristics of bacterial vaginosis differed according to HIV status in high-risk US women. METHODS: Prevalence of bacterial vaginosis was assessed by Gram's stain and clinical criteria for 854 HIV-infected and 434 HIV-uninfected women enrolled in the HIV Epidemiology Research (HER) Study. Multiple logistic regression techniques were used to determine whether HIV infection independently predicted bacterial vaginosis. RESULTS: Almost half (46%) the women had bacterial vaginosis by Gram's stain. The prevalence of bacterial vaginosis was 47% in the HIV-positive women compared with 44% in the HIV-negative women; this difference was not statistically significant (p = 0.36). After adjustment for other covariates, HIV-positive women were more likely than HIV-negative women to have bacterial vaginosis (odds ratio (OR) 1.31; 95% confidence interval (CI) 1.01-1.70) by Gram's stain but not by clinical criteria (OR 1.16; CI 0.87-1.55). Among HIV-positive women, use of antiretroviral drugs was associated with a lower prevalence of bacterial vaginosis (adjusted OR 0.54; Cl 0.38-0.77). CONCLUSIONS: In this cross-sectional analysis of high-risk US women, HIV infection was positively correlated with bacterial vaginosis diagnosed by Gram's stain.  (+info)

An adenovirus with enhanced infectivity mediates molecular chemotherapy of ovarian cancer cells and allows imaging of gene expression. (14/357)

The adenovirus (Ad) is a useful vector for cancer gene therapy due to its unparalleled gene transfer efficiency to dividing and quiescent cells. Primary cancer cells, however, often have highly variable or low levels of the requisite coxsackie-adenovirus receptor (CAR). Also, assessment of gene transfer and vector persistence has been logistically difficult in human clinical trials. We describe here two novel bicistronic adenoviral (Ad) vectors, AdTKSSTR and RGDTKSSTR, which contain the herpes simplex virus thymidine kinase gene (TK) for molecular chemotherapy and bystander effect. In addition, the viruses contain the human somatostatin receptor subtype-2 gene (SSTR2), the expression of which can be noninvasively imaged. We enhanced the infectivity of RGDTKSSTR by genetically incorporating the RGD-4C motif into the HI-loop of the fiber. This allows the virus to circumvent CAR deficiency by binding to alpha(v)beta(3) and alpha(v)beta(5) integrins, which are highly expressed on most ovarian cancers. The expanded tropism of RGDTKSSTR results in increased infectivity of purified primary ovarian cancer cells and allows enhanced gene transfer in the presence of malignant ascites containing anti-Ad antibodies. RGDTKSSTR may be a useful agent for treating ovarian cancer in clinical trials.  (+info)

Structural mechanisms of QacR induction and multidrug recognition. (15/357)

The Staphylococcus aureus multidrug binding protein QacR represses transcription of the qacA multidrug transporter gene and is induced by structurally diverse cationic lipophilic drugs. Here, we report the crystal structures of six QacR-drug complexes. Compared to the DNA bound structure, drug binding elicits a coil-to-helix transition that causes induction and creates an expansive multidrug-binding pocket, containing four glutamates and multiple aromatic and polar residues. These structures indicate the presence of separate but linked drug-binding sites within a single protein. This multisite drug-binding mechanism is consonant with studies on multidrug resistance transporters.  (+info)

Chondrolysis of the glenohumeral joint following a color test using gentian violet. (16/357)

Two patients developed chondrolysis following injection of 0.4% aqueous gentian violet into the glenohumeral joint to visualize a rotator cuff tear during surgery. In both cases, conventional radiographs revealed joint space narrowing 10-12 months after surgery. Histological examination of the humeral heads revealed loss of the articular cartilage.  (+info)