Differentiation of resistance phenotypes among erythromycin-resistant streptococci

Although macrolide antibiotics have proved to be a valuable alternative to beta-lactam antibiotics in the treatment of respiratory tract infections, resistance to these agents is now becoming established in streptococci, especially among Streptococcus pneumoniae isolates. Of particular concern is the emergence of cross-resistance to 14-, 15- and 16-membered macrolides, licosamides and group B streptogramins (MLSb phenotype). MLS resistance can be expressed either constitutively (cMLS phenotype) or inducibly (iMLS phenotype). MLS resistance is mediated by two classes of methylase genes--the conventional erm(B) and recently described erm(A) determinants. A new macrolide efflux mechanism has been described for streptococci, in which it is associated with a new resistance pattern (M phenotype) characterized by resistance to 14- and 15-membered macrolides, and susceptibility to 16-membered macrolides, lincosamides and streptogramin B. The recognition of the prevalence of M phenotype in streptococci has implications for sensitivity testing and may have an impact on the choice of antibiotic therapy in clinical practice. While M resistance is similar in S. pyogenes and S. pneumoniae being mediated by mef(A) and mef(E), respectively, MLS resistance in both species appears to be genotypically and phenotypically more varied. Differentiation of M and MLS phenotypes of erythromycin-resistant strains can be performed using the erythromycin-clindamycin double-disc method (ECDD). Distinguishing not only M resistance but also constitutively or inducibly MLS phenotype by ECDD in S. pyogenes is easily and reliably achieved. Inducible MLS phenotype S. pyogenes strain is genotypically and phenotypically heterogeneous and is further subdivided into three recently described subtypes, iMLS-A, iMLS-B and iMLS-C, by a triple-disk test with erythromycin plus clindamycin and josamycin. While distinguishing M from MLS resistance in S. pneumoniae by ECDD test is easily and reliably achieved, the differentiation between constitutive and inducible MLS resistance is by far more uncertain. The meaning of inducible MLS resistance appears to be different in S. pneumoniae from that in S. pyogenes. In order to easily differentiate, within erythromycin-resistant pneumococci, not only the strains of the M phenotype from those with MLS resistance but also among the latter, cMLS from iMcLS strains, a triple-disk test has been set up by adding a rokitamycin disk to the conventional     

Carbamazepine dosage and its blood serum level in children

Evaluating in 62 children aged from 4 months to 14 years (mean age 3 years 7 months) the correlation between the carbamazepine dosage (carbamazepine was given as the only drug in 21 cases, and as one of several drugs in 41) the authors failed to find a simple correlation. Nevertheless, most children receiving the "proper" doses had therapeutic plasma carbamazepine levels. Moreover, it was found that carbamazepine dose increase over 25 mg/kg daily caused on further rise of its plasma level.     

2. Survival Impact of HER-2/Neu, Cox-2, Urokinase Plasminogen Activator (upa), Cytokeratin 17/5,6 and other Markers with Long-Term Outcome of Early Breast Cancer. Report from the British Columbia Tissue Micro-Array Project (BCTMAP)

Tumor samples are available from over 19,600 Stage I-III breast cancer patients treated according to evolving British Columbia guidelines from 1978 to 1990. A tissue mico-array (TMA) was constructed from 930 of these patients, all of whom participated in randomized or phase II studies. Outcome was defined as 20-year Breast Cancer specific Survival (BrCaSS), with events defined as Breast Ca death. Follow up was median 17.8 years (ranges 11–28). Multiple tumor markers were tested, and results correlated with 20-year BrCaSS for markers expressed versus non-expressed. No difference in BrCaSS was found for aromatase, integrin-linked kinase (ILK), IGF-1 and Topo-isomerase-2. The negative predictive value of IHC versus FISH and ACIS-IHC versus FISH was 96 and 97%, respectively. The positive predictive value of IHC versus FISH and ACIS-IHC versus FISH was 84 and 84%, respectively. All tests, with the exception of HER-2 FISH were done by IHC. Results of other markers (VEGF, ER/PgR, hypoxia markers, etc.), and an interactive multivariate analysis adjusting for conventional prognostic factors and for all above markers, are in progress. Conclusions 1. The TMA is a technique which provides opportunity for rapid screening of multiple genetic markers.2. Expression of Her-2/Neu, uPA, Cox-2 and Cytokeratin 17/5,6 (but not of Aromatase, ILK, TOPO-II and IGF-1) is associated with inferior BrCaSS.3. HER-2 determination by ACIS-IHC provides comparable results to IHC done manually (with a potential for more uniform reporting), and both provide comparable results to Her-2 assessment by FISH. ^** ACIS-IHC:IHC red by Automated Cell Image System (M.L.)     

Hemangiomas of the external auditory canal:a literature review and two new case reports

Aim  

The aim of this paper is to present two case reports of patients with hemangiomas of the external auditory canal, and to overview all cases published in English language literature so far.     

Granular-cell tumor: a rare variant of mammary tumor

BACKGROUND: Granular cell tumor (GCT) is a rare variant of mammary tumor beset with diagnostic dilemmas that may be resolved by using numerous, very complex, enzymohistochemical and immunohistochemical methods. CASE REPORTS: We reported three female patients 16, 21 and 65 years old, operated on for mammary tumor at the Surgical Clinic of the School of Medicine in Nis, over the period of thirty years, 1977 to 2007. During this period 14.022 mammary tumors were diagnosed, including these three cases. These tumors had benign characteristics, without associated tumors in other localizations. A typical histological feature of GCT was a granular cytoplasm in large ovoid cells, organized like nests or like a trabecular arrangement. The tumors were analyzed by sets of histochemical, enzymohistochemical, immunohistochemical methods as well as ultrastructural examination. Protein, S-100 neuron-specific enolase and vimentin expressed a diffuse and intensive immunohistochemical activity, while expression of estrogen and progesterone receptors, as well as HER-2 oncoprotein was negative. The ultrastructural analysis confirmed that the tumor cells were enriched by lysosomes and consequential disorganization of cytoplasm. CONCLUSION: The reported enzymo- and immunohistochemical combined methods provide a precise diagnosis and confirm the GCT's neural origin, which has been disputed for years.     

Clinical utility of stem cells for periodontal regeneration

The aim of this review is to discuss the clinical utility of stem cells in periodontal regeneration by reviewing relevant literature that assesses the periodontal-regenerative potential of stem cells. We considered and described the main stem cell populations that have been utilized with regard to periodontal regeneration, including bone marrow-derived mesenchymal stem cells and the main dental-derived mesenchymal stem cell populations: periodontal ligament stem cells, dental pulp stem cells, stem cells from human exfoliated deciduous teeth, stem cells from apical papilla and dental follicle precursor cells. Research into the use of stem cells for tissue regeneration has the potential to significantly influence periodontal treatment strategies in the future.     

The association between triglyceride to high-density-lipoprotein cholesterol ratio and insulin resistance in a multiethnic primary prevention cohort

The objective was to explore the clinical utility of triglyceride (TG) to high-density lipoprotein cholesterol (HDL-C) ratio in predicting insulin resistance (IR) in 4 ethnic groups and the relationship between IR and TG/HDL-C in comparison to that with other lipid measures. Apparently healthy Aboriginals, Chinese, Europeans, and South Asians (N = 784) were assessed for sociodemographics, lifestyle, anthropometry, lipids, glucose, and insulin. The homeostasis model assessment of IR was used as a measure of IR. Compared with other lipid parameters, TG/HDL-C was the highest correlate of the homeostasis model assessment of IR (age and sex adjusted) in Aboriginals (r = 0.499, P < .001), Chinese (r = 0.432, P < .001), Europeans (r = 0.597, P < .001), and South Asians (0.372, P < .001). For a 1-unit increase in TG/HDL-C, the odds of being insulin resistant increased about 4 times (odds ratio [OR], 3.95; 95% confidence interval [CI], 1.86-8.42; P < .001) in Aboriginals, 3.4 times in Chinese (OR, 3.44; 95% CI, 1.79-6.62; P < .001), 1.9 times in Europeans (OR, 1.94; 95% CI, 1.00-3.75; P = .049), and 1.8 times in South Asians (OR, 1.77; 95% CI, 0.91-3.45; P = .094) (age, sex, smoking, physical activity, body mass index, and waist circumference adjusted). Receiver operating characteristic curve analyses revealed areas under the curve (95% CI) of 0.777 (0.707-0.847) in Aboriginals, 0.723 (0.647-0.798) in Chinese, 0.752 (0.675-0.828) in Europeans, and 0.676 (0.590-0.762) in South Asians. Optimal cutoffs (sensitivity, specificity) of TG/HDL-C for identifying individuals with IR were 0.9 (93.0%, 51.9%), 1.1 (71.7%, 61.5%), 1.1 (73.5%, 70.9%), and 1.8 (52.0%, 77.9%) in Aboriginal, Chinese, European, and South Asian individuals, respectively. The TG/HDL-C ratio may be a good marker to identify insulin-resistant individuals of Aboriginal, Chinese, and European, but not South Asian, origin.