Diversity and sharing of Haemophilus influenzae strains colonizing healthy children attending day-care centers

BACKGROUND: Children attending day-care centers (DCCs) are at risk for Haemophilus influenzae nasopharyngeal colonization and acute otitis media. The degree to which a given strain circulates within a day-care center and the heterogeneity of strains among DCCs in a geographic area are not well-characterized. This study describes the prevalence rates of H. influenzae colonization in a large number of children attending day-care centers and examines the genetic diversity of colonizing strains and the degree of sharing among children. METHODS: Throat cultures were collected from 198 healthy children <3 years old attending 16 day-care centers in Michigan. All H. influenzae isolates were genetically typed by enterobacterial repetitive intergenic consensus PCR as the initial screening technique to identify unique strains within each child. Pulsed field gel electrophoresis was used subsequently to examine the genetic diversity of strains between children. RESULTS: There were 127 (64%) children colonized with H. influenzae. Wide variation in rates of colonization was identified among day-care centers (0 to 95%). A total of 179 genetically unique H. influenzae strains were isolated, and 47 children (37%) were colonized with 2 or more genetically distinct H. influenzae organisms. Evidence of sharing of the same strain in different children was found in 13 of 15 colonized DCCs and 23% of genotypically unique strains were shared. CONCLUSION: The degree of sharing of H. influenzae among children in this study suggests transmission of these potentially pathogenic microorganisms in day-care centers.     

Patency of the ductus arteriosus in the premature infant: is it pathologic? Should it be treated?

PURPOSE OF REVIEW: The ductus arteriosus is a vessel that connects the pulmonary artery to the aorta and provides a pulmonary-to-systemic diversion during fetal life. In the vast majority of infants, the ductus arteriosus closes by 3 days of life. In some infants, especially preterm infants with lung disease, there is delayed closure of the ductus arteriosus. There has been controversy as to whether or when the ductus arteriosus should be closed by either pharmacologic or surgical methods. RECENT FINDINGS: There have been several epidemiologic studies describing an association between a patent ductus arteriosus and the development of morbidities, such as chronic lung disease. These associations have suggested to some that a causal relationship exists between patency of the ductus arteriosus and chronic lung disease and other morbidities. However, recent metaanalyses of randomized, controlled trials of the use of indomethacin for the prevention and treatment of the patent ductus arteriosus have not documented a decrease in the incidence of these morbidities after treatment, despite success in closure of the patent ductus arteriosus. SUMMARY: In preterm infants, patency of the ductus arteriosus may represent a normal physiologic adaptation to allow shunting from either systemic-to-pulmonary circulation (eg, in the first day of life) or from pulmonary-to-systemic circulation (eg, in the presence of severe lung disease). Therapies designed to close the ductus arteriosus are contraindicated in some settings and should not be considered a standard of care at any time until these therapies are proven to decrease long-term clinical morbidities in randomized, placebo-controlled trials.     

Redefining primary pediatric care for children with special health care needs: the primary care medical home

PURPOSE OF REVIEW: As considerations of the quality of health care have matured, the role of pediatric primary care providers and models for the delivery of primary care have received growing attention. Particularly for children with chronic conditions, the need for proactive, planned, and coordinated care delivered in partnership with consumers has become more apparent. The primary care medical home has emerged as a model favored by national organizations representing pediatricians and family physicians as well as national public health policy makers, yet implementation of this model remains limited and the evidence base for its value is not yet highly developed. RECENT FINDINGS: Most studies of primary care outcomes involve individual elements of the medical home such as care coordination and continuity of care. Limited data that are emerging from studies of the medical home model as a whole in practice settings suggest improvements in patient satisfaction and in some areas of utilization. No data are available that examine specific functional or physical health outcomes associated with primary care models like the medical home. SUMMARY: The pediatric primary care medical home provides a care model for both well children and those with special health care needs that expands primary care services beyond those provided in the examination room by individual providers to include systemic services such as patient registries, explicit care planning and care coordination, planned co-management with specialists, patient advocacy, and patient education. There is an immediate need for large-scale, practice-based studies of the outcomes for children and youth, providers, and the health care system when such improvements in primary care are implemented.     

The presence and function of phosphodiesterase type 5 in the rat myometrium

OBJECTIVE: Cyclic nucleotide phosphodiesterases (PDEs) are a diverse enzyme group with multiple regulatory properties and wide tissue distribution. Such activity includes cyclic adenosine (cAMP) and guanosine monophosphate (cGMP) breakdown. The type 5 isoform (PDE-5, cGMP specific) is the target of specific antagonists (ie, sildenafil, Viagra). We tested the hypothesis that PDE-5 is present in rat myometrium and modulates myometrial activity. STUDY DESIGN: Full-thickness uterine wall was collected from nonpregnant (n=3) and pregnant Sprague-Dawley rats on days 10 (n=4), 17 (n=6), 22 nonlabor (n=5), and 22 during term labor (TL, n=4). Preterm labor (PTL, n=3) was induced in some animals on day 16 with 15 mg/kg mifepristone (RU 486). Tissue samples were prepared for Western blotting using a monoclonal antibody against rodent PDE-5. In a second series, cumulative doses of sildenafil (0.005, 0.05, 0.5, 5 mg/kg, intraperitoneal) were administered and the effect on uterine contractility recorded in vivo during term (TL, n=7) and preterm labor (PTL, n=6). Saline solution-injected rats provided temporal control. Uterine contractility was estimated from intrauterine pressure (IP) measured electronically with a sensor tip pressure catheter. Heart rate was recorded simultaneously using electrodes attached to the chest and connected to the same data acquisition system. RESULTS: PDE-5 immunoreactivity was present in the nonpregnant rat uterus and at all gestational times studied, although the expression was unaffected by either pregnancy or the state of labor (preterm or term). A dominant antibody-specific band was identified at 86 kd in the uterine samples, contrasting with lung where the 100-kd PDE-5 isoform was most abundant. Two additional lower molecular weight (55 and 32 kd) bands were also identified as antibody specific. Despite the lack of change in PDE-5 during pregnancy, sildenafil reduced IP during TL and PTL beginning at 0.5 mg/kg. The highest dose of sildenafil reduced IP during both TL and PTL by 45% and 59% of baseline, respectively (two-way analysis of variance, P<.01). This effect was not accompanied by changes in heart rate. CONCLUSION: PDE-5 is constitutively present in the rat uterine wall. There was no observed change in the PDE-5 protein expression throughout pregnancy. In contrast to the lung, the uterus expresses an 80-kd PDE-5 isoform. Sildenafil in pharmacologic doses inhibits mechanical uterine activity and might be of benefit if selectively used for treatment of preterm labor.     

Intrauterine pressure during the second stage of labor in obese women

OBJECTIVE: The perception that obese women have longer labors and a higher frequency of operative delivery because they are "poor pushers" persists despite the absence of objective study. We tested the hypothesis that obese women generate inadequate intrauterine pressure during the second stage of labor. METHODS: Intrauterine pressure was prospectively measured in 71 women during the second stage of labor. Obesity was defined as a body mass index (BMI) greater than 29 (n = 17). A BMI below 25 was normal (n = 40). Women with a BMI between 26 and 29 (n = 14) were considered overweight. All women labored with epidural analgesia and were alert and responsive throughout the study. After recording the baseline contractility, a standardized Valsalva maneuver was performed during contractions. The area under the intrauterine pressure curve (integral) was used as an estimate of uterine contractility. RESULTS: All women delivered vaginally. There were no significant differences in baseline uterine contractility among obese, overweight, and normal women either before (obese 1,787 mm Hg/s; 95% confidence interval [CI] 1,164, 2,742 versus normal 1,569 mm Hg/s; 95% CI 718, 2,371 versus overweight 1,770 mm Hg/s; 95% CI 1,305, 2,835; P =.223) or during Valsalva maneuver (obese 2,831 mm Hg/s; 95% CI 1,771, 4,599 versus normal 2,637 mm Hg/s; 95% CI 1,240, 4,390 versus overweight 2,813 mm Hg/s; 95% CI 1,209, 4,982; P =.742). A BMI greater than 25 was associated with a higher frequency of oxytocin augmentation (P =.037). Univariate analysis revealed a relationship between labor duration and BMI (r = 0.299, P =.018). Obese women labored longer during the active phase (one-way analysis of variance, P =.02), but second-stage duration was similar among groups (one-way analysis of variance P =.44). Obesity did not increase the incidence of perineal lacerations (P =.82) or frequency of operative delivery (relative risk obese versus nonobese = 0.212; 95% CI 0.04, 1.05). CONCLUSION: Obese women produce second-stage intrauterine pressures equivalent to women with a normal BMI, although they may require oxytocin augmentation more often. LEVEL OF EVIDENCE: II-2     

DNA microarray analysis of predominant human intestinal bacteria in fecal samples

A microarray method was developed for the detection of 40 bacterial species reported in the literature to be predominant in the human gastrointestinal tract. The 40 species include seven species each of Bacteroides and Clostridium, six species of Ruminococcus, five species of Bifidobacterium, four species of Eubacterium, two species each of Fusobacterium, Lactobacillus and Enterococcus, and single species each of Collinsella, Eggerthella, Escherichia, Faecalibacterium and Finegoldia. Three 40-mer oligos specific for each bacterial species were designed based on comparison of the 16S rDNA sequences available in the GenBank database, and were used to make the DNA-array on epoxy slides. Using two universal primers, the 16S rRNA gene from bacteria present in fecal samples were amplified and labeled with Cyanine5-dCTP by PCR, and then hybridized to the DNA-array. After resolving some difficulties caused by sequence conflicts in GenBank and inaccurate reference strains, all 40 bacterial reference species gave positive results. The microarray method was used to screen fecal samples obtained from 11 healthy human volunteers for the presence of these intestinal bacteria. The results indicated that 25-37 of the 40 species could be detected in each fecal sample and that 33 of the species were found in a majority of the samples.     

Awareness and prevention of error in clinical decision-making

The risk of errors in the planning and delivery of health care is an inescapable feature of clinical practice for which health providers have developed sophisticated defences. However, errors still occur. This paper, the final in a four-part series on nurses' decision-making and judgement, illustrates some common pitfalls facing clinicians who have to make complex decisions and judgements, and suggests simple techniques to help combat some of the systematic errors people make when exercising judgement and making choices.     

A consensus statement on empiric therapy for suspected gram-positive infections in surgical patients

BACKGROUND: Multidrug resistance among gram-positive pathogens in tertiary and other care centers is common. A systematic decision pathway to help select empiric antibiotic therapy for suspected gram-positive postsurgical infections is presented. DATA SOURCES: A Medline search with regard to empiric antibiotic therapy was performed and assessed by the 15-member expert panel. Two separate panel meetings were convened and followed by a writing, editorial, and review process. CONCLUSIONS: The main goal of empiric treatment in postsurgical patients with suspected gram-positive infections is to improve clinical status. Empiric therapy should be initiated at the earliest sign of infection in all critically ill patients. The choice of therapy should flow from beta-lactams to vancomycin to parenteral linezolid or quinupristin-dalfopristin. In patients likely to be discharged, oral linezolid is an option. Antibiotic resistance is an important issue, and in developing treatment algorithms for reduction of resistance, the utility of these new antibiotics may be extended and reduce morbidity and mortality.