Characterization of Recombinant Fluoroquinolone-Resistant Pneumococcus-Like Isolates

Fourteen fluoroquinolone-resistant streptococcal isolates with recombinant DNA topoisomerase genes, preliminarily identified as pneumococci, were further characterized using phenotypic and genotypic approaches. Phenotypic tests classified them as atypical pneumococci. Phylogenetic relationships were analyzed by using the sequences of seven housekeeping alleles from these isolates and from isolates of Streptococcus pneumoniae, Streptococcus mitis, Streptococcus oralis, and Streptococcus pseudopneumoniae. Four isolates grouped with S. pneumoniae, seven grouped with S. pseudopneumoniae, and three grouped with S. mitis. These results generally agreed with those obtained with an optochin susceptibility test and with the organization of the atp operon chromosomal region, encoding the F_oF₁ H⁺-ATPase (the target of optochin). All seven isolates grouping with S. pseudopneumoniae share the same spr1368-atpC-atpA gene order; all four grouping with S. pneumoniae share the spr1368-IS1239-atpC-atpA order, and two out of the three grouping with S. mitis share the spr1284-atpC-atpA order. In addition, evidence for recombination within the seven housekeeping alleles of the S. pseudopneumoniae population was provided by several methods: the index of association (0.4598, P < 0.001), the pairwise homoplasy index, and the split-decomposition method. This study confirms the existence of pneumococci among the alpha-hemolytic streptococci with DNA topoisomerase genes showing a mosaic structure and reveals a close relationship between atypical pneumococci and S. pseudopneumoniae.     

Is the <Emphasis Type="Italic">E</Emphasis>/<Emphasis Type="Italic">V</Emphasis><Subscript>p</Subscript> index useful for evaluating prognosis in chronic heart failure with atrial fibrillation? A pilot study

Background  

The ratio of transmitral peak E wave velocity to color flow propagation velocity (E/V _p index) has proved to be a significant predictor of prognosis in cardiac diseases with sinus rhythm. However, its usefulness in patients with atrial fibrillation (AF) and heart failure has not yet been established. The aim of this study was to determine the feasibility of using the E/V _p index for the prediction of mortality and heart failure hospitalization in this group.     

High frequency percussive ventilation and low FiO(2)

Background

High-frequency percussive ventilation (HFPV) is an effective rescue therapy in ventilated patients with acute lung injury. High levels of inspired oxygen (FiO₂) are toxic to the lungs. The objective of this study was to review a low FiO₂ (0.25)/HFPV protocol as a protective strategy in burn patients receiving mechanical ventilation greater than 10 days.

Methods

A single-center, retrospective study in burn patients between December 2002 and May 2005 at the LAC + USC Burn Center. Demographic and physiologic data were recorded from time of admission to extubation, 4 weeks, or death.

Results

32 subjects were included in this study, 1 patient failed the protocol. 23 of 32 (72%) patients were men and mean age was 46 ± 15 years. Average TBSA burn was 30 ± 20 with 9 of 32 (28%) having >40% TBSA involved. Average burn index was 76 ± 21. 22 of 32 (69%) had inhalation injury and 23 of 32 (72%) had significant comorbidities. Average ventilator parameters included ventilator days 24 ± 12, FiO₂ 0.28 ± 0.03, PaO₂ 107 ± 15 Torr, PaCO₂ 42 ± 4 Torr, and PaO₂/FiO₂ ratio 395 ± 69. 16 of 32 (50%) patients developed pneumonia and 9 of 32 (28%) died. No patient developed ARDS, barotrauma, or died from respiratory failure. There was no association between inhalation injury and mortality in this group of patients.

Conclusion

A low FiO₂/HFPV protocol is a safe and effective way to ventilate critically ill burn patients. Reducing the oxidative stress of high inspired oxygen levels may improve outcome.     

Cytomegalovirus Infection Renal Transplant Recipients: Risk Factors and Outcome

Objective

Cytomegalovirus (CMV) is the most common viral infection after allotransplantation; it can be a major cause of morbidity and mortality. Our aim was to analyze the main risk factors that lead to development of CMV infection and disease.

Patients and Methods

We retrospectively analyzed 207 patients who received a renal allograft from May 2003 to December 2007. Three patients (D−/R−) were excluded. CMV infection was defined by the detection of 2 or more positive tests for pp65 antigenemia and CMV disease by evidence of attributable symptoms in need of antiviral treatment.

Results

Thirty-two patients (15.7%) presented active CMV infections and another 35 (17.2%), CMV disease. The mean follow-up was 27.8 ± 17 months. Prior to transplantation, 9.2% of patients were seronegative (D+/R−) and 77.9% seropositive (D+/R+). Compared with noninfected patients, those with CMV infection/disease were older and received an allograft from an older donor. Upon logistic regression analysis, recipient age older than 55 years, induction therapy with Thymoglobulin, and maintenance immunosuppression with cyclosporine were the major risk factors to develop CMV disease. An early acute rejection episode was more frequent and renal function measured by serum creatinine poorer until 18 months posttransplantation among CMV-infected versus noninfected patients.

Conclusions

Our data showed that CMV infection is a common complication after kidney transplantation associated with older age, induction treatment with antilymphocyte globulin, worse renal function, and increased patient morbidity.     

The presence of periodontopathogens associated with the tumour necrosis factor-alpha expression in patients with different periodontal status

The purpose of this study was to investigate the relationship between P gingivalis, T forsythia, T denticola, P intermedia, and A. actinomycetemcomitans in the sulci or pockets of patients with gingivitis (G), mild chronic periodontitis (MiCP), moderate chronic periodontitis (MoCP) and severe periodontitis (SP), and the expression of TNF-alpha in gingival tissue associated with clinical parameters. Six patients with G, 7 with MiCP, 23 with MoCP and 7 with SP were recruited. Pathogens obtained from the sulci or pockets were identified by PCR, and expression of TNF-alpha from gingival tissue was analysed Probing depth (PD), clinical attachment level (CAL) and loss of bone were recorded. P gingivalis was detected at the following rates: 16.6% in subjects with G 57.1% in MiCP 57.8 % in MoCP and 58.1% in SP (p < 0.05). P intermedia was not identified in subjects with G A. actinomycetemcomitans was only identified in subjects with MoCP (31.5%) and SP (42.8%). T denticola and T forsythia were identified in all subject groups. Bacterial combinations were identified as follows: P denticola + P intermedia and PR intermedia + T forsythia were associated (p = 0.04, p = 0.02) with the presence of TNF-alpha mRNA in 20% and 25% of subjects, respectively. P gingivalis + A. Actinomycetemcomitans andA. actinomycetemcomitans + T forsythia were associated with severe PD and CAL, respectively. The association between the presence of P intermedia and expression levels of TNF-alpha was significant (p = 0.05). These results indicate that the proportion of patients with P gingivalis increases with the progression of disease. We observed that the presence of P intermedia may trigger the expression of TNF-alpha and cause a worsening of the patient's clinical status.     

MR Denoising Increases Radiomic Biomarker Precision and Reproducibility in Oncologic Imaging

Journal of Digital Imaging - Several noise sources, such as the Johnson–Nyquist noise, affect MR images disturbing the visualization of structures and affecting the subsequent extraction of...