Multicenter evaluation of the BD max enteric bacterial panel PCR assay for rapid detection of Salmonella spp., Shigella spp., Campylobacter spp. (C. jejuni and C. coli), and Shiga toxin 1 and 2 genes.

Diarrhea due to enteric bacterial pathogens causes significant morbidity and mortality in the United States and worldwide. However, bacterial pathogens may be infrequently identified. Currently, culture and enzyme immunoassays (EIAs) are the primary methods used by clinical laboratories to detect enteric bacterial pathogens. We conducted a multicenter evaluation of the BD Max enteric bacterial panel (EBP) PCR assay in comparison to culture for the detection of Salmonella spp., Shigella spp., Campylobacter jejuni, and Campylobacter coli and an EIA for Shiga toxins 1 and 2. A total of 4,242 preserved or unpreserved stool specimens, including 3,457 specimens collected prospectively and 785 frozen, retrospective samples, were evaluated. Compared to culture or EIA, the positive percent agreement (PPA) and negative percent agreement (NPA) values for the BD Max EBP assay for all specimens combined were as follows: 97.1% and 99.2% for Salmonella spp., 99.1% and 99.7% for Shigella spp., 97.2% and 98.4% for C. jejuni and C. coli, and 97.4% and 99.3% for Shiga toxins, respectively. Discrepant results for prospective samples were resolved with alternate PCR assays and bidirectional sequencing of amplicons. Following discrepant analysis, PPA and NPA values were as follows: 97.3% and 99.8% for Salmonella spp., 99.2% and 100% for Shigella spp., 97.5% and 99.0% for C. jejuni and C. coli, and 100% and 99.7% for Shiga toxins, respectively. No differences in detection were observed for samples preserved in Cary-Blair medium and unpreserved samples. In this large, multicenter study, the BD Max EBP assay showed superior sensitivity compared to conventional methods and excellent specificity for the detection of enteric bacterial pathogens in stool specimens.

Optical polymers with tunable refractive index for nanoimprint technologies.

In order to realize a versatile high throughput production of micro-optical elements, UV-curable polymer composites containing titanium dioxide nanoparticles were prepared and characterized. The composites are based on an industrial prototype epoxy polymer. Titanium dioxide nanoparticles smaller than 10 nm were synthesized by the nonaqueous sol method and in situ sterically stabilized by three different organic surfactants. The composites exhibit high transparency. Distinct alteration of optical transmission properties for visible light and near IR wavelength range could be avoided by adaption of the stabilizing organic surfactant. Most importantly, the refractive index (RI) of the composites that depends on the fraction of incorporated inorganic nanoparticles could be directly tuned. E.g. the RI at a wavelength of 635 nm of a composite containing 23 wt% titanium dioxide nanoparticles is increased to 1.626, with respect to a value of 1.542 for the pure polymer. Furthermore, it could be demonstrated that the prepared inorganic-organic nanocomposites are well suited for the direct fabrication of low-cost micro-optical elements by nanoimprint lithography. A low response of the optical composite properties to temperature treatment up to 220 °C with a shrinkage of only about 4% ensures its application for integrated micro-optical elements in industrial production.

Study protocol: trial of inflation osteoplasty in the management of tibial plateau fractures.

INTRODUCTION: Restoration of articular congruency is a key factor in preventing post-traumatic osteoarthritis following tibial plateau fractures. Current surgical techniques using a bone tamp carry the risk of joint perforation and comminution of the depressed fragments which affect patient outcome. Successful use of inflation osteoplasty has been reported in both in vitro studies (Broome et al. in J Orthopaed Traumatol 13(2):89-95, 2012; Mauffrey et al. in Patient Saf Surg 6:6, 2012) and case reports in the management of fractures of the calcaneus, cuboid, distal radius, tibial plateau and acetabulum (Gupta et al. in Foot Ankle Int 32(2):205-210, 2011; Heim et al. in Foot Ankle Int 29(11):1154-1157, 2008; Konig et al. in Case Rep Unfallchirurg 109(4):328-331, 2006; Reiley in J Orthop Trauma 17:141-163, 2006). The aim of our study is to assess whether the use of the balloon osteoplasty improves the quality of reduction of a depressed tibial plateau fracture when compared to traditional methods of fracture reduction. METHOD: This is a single-centred randomised trial. We will recruit 24 adult patients admitted with either a depressed or split depressed tibial plateau fracture (medial or lateral) requiring surgical intervention. Consenting patients will be randomly allocated to the two treatment groups. Patients with concomitant injuries influencing the management of the tibial plateau fracture will be excluded from our study. The primary outcome measure is the quality of reduction based on the post-operative CT scan. Secondary outcome measures will be any surgical complication and patient satisfaction, measured using the Oxford Knee score and SF12 questionnaire at 3, 6 and 12 months. Principal analysis will be for the success of fracture reduction from the two techniques and the effect the operative technique had on patient satisfaction and the prevalence of surgical complications.

Evaluation of resistless Ga⁺ beam lithography for UV NIL stamp fabrication.

This paper presents an alternative rapid prototyping approach for the fabrication of stamps for UV nanoimprint lithography. In this process, areas implanted with gallium serve as an etch mask for the dry etching of quartz. The implantation is performed using a focused ion beam system. To avoid charging of the quartz substrate the use of thin layers of chromium or carbon on the quartz substrate has been evaluated. The resulting quartz structures exhibit very smooth surfaces after dry etching, if the implantation dose is high enough to form a stable etch mask. Furthermore, anisotropic etching could be realized by optimization of a quartz etching process involving C4F8 and O2 after the use of resistless Ga(+) beam lithography. Finally, imprints into a UV curing resist are performed successfully with the manufactured stamps, proving that the presence of Ga rich areas on the stamp is not detrimental to the curing of the resist or the functionality of the anti-sticking layer.

The role of lumbar lordosis and pelvic sagittal balance in femoroacetabular impingement.

AIMS: The purpose of this study was to evaluate spinopelvic mechanics from standing and sitting positions in subjects with and without femoroacetabular impingement (FAI). We hypothesize that FAI patients will experience less flexion at the lumbar spine and more flexion at the hip whilst changing from standing to sitting positions than subjects without FAI. This increase in hip flexion may contribute to symptomatology in FAI. PATIENTS AND METHODS: Male subjects were prospectively enrolled to the study (n = 20). Mean age was 31 years old (22 to 41). All underwent clinical examination, plain radiographs, and dynamic imaging using EOS. Subjects were categorized into three groups: non-FAI (no radiographic or clinical FAI or pain), asymptomatic FAI (radiographic and clinical FAI but no pain), and symptomatic FAI (patients with both pain and radiographic FAI). FAI was defined as internal rotation less than 15° and alpha angle greater than 60°. Subjects underwent standing and sitting radiographs in order to measure spine and femoroacetabular flexion. RESULTS: Compared with non-FAI controls, symptomatic patients with FAI had less flexion at the spine (mean 22°, sd 12°, vs mean 35°, sd 8°; p = 0.04) and more at the hip (mean 72°, sd 6°, vs mean 62°, sd 8°; p = 0.047). Subjects with asymptomatic FAI had more spine flexion and similar hip flexion when compared to symptomatic FAI patients. Both FAI groups also sat with more anterior pelvic tilt than control patients. There were no differences in standing alignment among groups. CONCLUSION: Symptomatic patients with FAI require more flexion at the hip to achieve sitting position due to their inability to compensate through the lumbar spine. With limited spine flexion, FAI patients sit with more anterior pelvic tilt, which may lead to impingement between the acetabulum and proximal femur. Differences in spinopelvic mechanics between FAI and non-FAI patients may contribute to the progression of FAI symptoms. Cite this article: Bone Joint J 2018;100-B:1275-9.

Intraneuronal ApoE in human visual cortical areas reflects the staging of Alzheimer disease pathology.

Alzheimer disease (AD) is marked by progressive loss of cortical neurons with associated cognitive decline. Multiple genetic and environmental factors likely contribute to this progressive loss. Such genetic factors include the polymorphic locus (APOE) that encodes apolipoprotein E (apoE). In order to investigate a possible correspondence between cellular localization of apoE and the neuropathology of AD, we examined the distribution of apoE-immunoreactive neurons in visual cortical areas with different apparent susceptibility to AD neuropathology (areas 17-primary sensory, 18-secondary sensory, and inferior temporal-association cortex) at different stages of AD pathology as described by Braak and Braak. We found that intraneuronal apoE was present at all these stages, however, only in visual cortical regions known to be vulnerable to AD. In the late stages, the laminar distribution of apoE-immunoreactivity matched the distribution of other markers of AD pathology, especially modified tau. These data support previous findings that intraneuronal apoE in neocortex is common in aged, nondemented controls and demonstrate that it may be more common in regions at risk for AD pathology. Thus, intraneuronal accumulation of apoE may be an attribute of cortical neurons that are more vulnerable to age-related injury with the presence of apoE antedating the classical indices of late-onset AD pathology.

Turicella otitidis mastoiditis in a healthy child.

Turicella otitidis, a coryneform bacterium, has been associated with acute otitis media. A 5-year-old girl developed acute mastoiditis. Turicella was isolated from the right and left middle ear fluid.

Infections caused by dematiaceous fungi: chromoblastomycosis and phaeohyphomycosis.

Because of the increased incidence of infections caused by dematiaceous fungi, it is important to clearly define the conceptual basis for the clinical nomenclature for infections caused by these fungi. When considering dematiaceous fungal infections, there is a continuum of diseases that can be separated into the three categories of chromoblastomycosis, phaeohyphomycosis, and mycetoma. The diseases chromoblastomycosis and phaeohyphomycosis are compared and contrasted in this chapter.

Mycetoma: a contemporary concept.

Mycetoma is a localized noncontagious infection that involves cutaneous and subcutaneous tissue, fascia, and bone. The disease is caused by either aerobic actinomycetes or fungi that are normally associated with soil and plant material. In the past, actinomycosis, botryomycosis, fungus balls, and some forms of Majocchi's granuloma trichophyticum have been confused with mycetoma. Antimicrobic chemotherapy and surgery are management approaches used to resolve this disease.

Elevated cAMP in intestinal epithelial cells during experimental cholera and salmonellosis.

Cholera and salmonellosis are two diarrheal diseases in which intestinal tissue cyclic adenosine monophosphate (cAMP) concentrations are elevated. Investigations of each experimental disease were initiated to identify the specific intestinal cells containing the elevated cAMP. Epithelial cells were eluted from the mucosa of infected and control intestinal loops of adult rabbits, after which the cAMP content of the epithelial cell fractions and the lamina propria cells was extracted and assayed. The identity of the epithelial cells (in the villus tip-to-crypt cell gradient) was monitored by measuring their intracellular alkaline phosphatase activity, while scanning electron microscopy was used to visualize the effects of infection and cell elution techniques. Clearly, in both experimental cholera and salmonellosis, elevated cAMP levels were associated with crypt epithelial cells. Villus tip epithelial cells from either infection tended to contain less cAMP than those of noninfected control tissue. In Salmonella-infected loops, it was apparent that cAMP was also elevated in lamina propria cell fractions. Lamina propria cells from V. cholerae-infected intestinal loops contained only basal levels of cAMP. In vitro exposure of isolated intestinal cells from normal rabbit intestine to a cell-free lysate of Salmonella resulted in elevation of cAMP in the epithelial cells and lamina propria cells. We conclude that in experimental cholera and salmonellosis, significant elevation of the cAMP levels occurred in intestinal crypt cells, consistent with an enterotoxin-mediated mechanism. In Salmonella-infected loops, it was unclear if the increased concentration of cAMP in lamina propria cells was generated by enterotoxin released from the invasive salmonellae or by prostaglandins formed during the inflammatory response to the bacteria, or by both mechanisms.

In vitro activity of minocycline against respiratory pathogens from patients with cystic fibrosis.

Our objective was to determine the in vitro activity of minocycline against isolates of Burkholderia cepacia (BC), Stenotrophomonas maltophilia (SM), and Pseudomonas aeruginosa (PA) cultured from the respiratory tract of patients with cystic fibrosis (CF). Cultures of BC, SM, and PA were isolated in a hospital bacteriology laboratory from the sputum or oropharyngeal cultures obtained from patients attending a Cystic Fibrosis Center, and were prospectively tested for in vitro sensitivity to minocycline by Kirby-Bauer disk diffusion. From January 1994 to July 1995, 116 cultures from 61 patients had at least one of the three pathogens; 9/61 (15%) patients had an isolate of BC, and 7/9 (78%) had an initial isolate sensitive to minocycline, of which 3 were sensitive only to minocycline; 2 cultures were resistant to all antibiotics. Four of 7 patients with BC were treated with minocycline; 3 patients developed resistant isolates 3-13 months after therapy. Five of 61 patients (8%) had an isolate of SM: 4/5 (80%) of these isolates were sensitive to minocycline, of which 1 was sensitive only to minocycline. Fifty-five of 61 patients (90%) had at least one PA isolate, with 112 morphotypes recovered from 90 cultures: 40/112 morphotypes (36%) were sensitive to minocycline, 65 (58%) were resistant, and 7 (6%) were intermediate in sensitivity. We conclude that the marked in vitro activity of minocycline against BC and SM isolated from patients with CF suggests that minocycline may have an adjunct role in the antimicrobial therapy of multidrug resistant, respiratory pathogens in CF.

The effect of anti-exotoxin A on the adherence of Pseudomonas aeruginosa to hamster tracheal epithelial cells in vitro.

One of the most important initial events of colonization and infection of epithelial tissues is the adherence of bacteria to mucosal surfaces. Bacterial adhesion to the epithelial cell may be mediated by a variety of adhesins, including exoproducts. One of these exoproducts, exotoxin A (EA) is a three-domain bacterial toxin that kills mammalian cells by gaining entry to the cytosol and inactivating protein synthesis. In the present study, HTE cultures, 2-4 weeks in vitro (containing both ciliated and non-ciliated cells), were treated for 1 hr with two different non-mucoid strains of Pseudomonas aeruginosa (1 x 10(8) organisms/ml) in the presence of anti-EA. 50 randomly selected fields were evaluated via SEM at x2500 magnification and the number of bacterial clusters/field quantitated. The results of this study indicate, first, that both piliated (ATCC15692) and non-piliated (PAKp) P. aeruginosa will bind to the HTE cells and, second, that treatment of HTE cells with either strain of P. aeruginosa in the presence of anti-EA will reduce bacterial binding by 25% to 50%. Thus, EA may participate in the adhesion of P. aeruginosa to respiratory tract epithelia.

Evolution of lymph thrombi in experimental Brugia malayi infections: a scanning electron microscopic study.

Lymph thrombi in cats experimentally-infected with Brugia malayi were examined by scanning electron microscopy. A variety of morphological forms were noted and it appeared that thrombi undergo a maturation process characterized by at least three transitional phases. Initially, the thrombus consists of erythrocytes encased in fibrin (Phase I). Phase II thrombi are characterized by the appearance of phagocytic cells and fibroblasts on the surface of the thrombus. At the end of the maturation process, the thrombus surface consists solely of fibroblasts or endothelial cells, perhaps derived from the vessel wall (Phase III). Occlusion of the lymphatic lumen by thrombi and the accompanying inflammatory response triggered by B. malayi infection may be a major factor in the pathogenesis of lymph stasis in this disorder.

Effect of thermal injury and immunosuppression on the dissemination of Candida albicans from the mouse gastrointestinal tract.

Candida albicans dissemination through the gastrointestinal tract was examined in mice given a thermal injury, immunosuppressive therapy, or both. After gastrointestinal tract colonization with C. albicans, mice were initially subjected to a 20% total body surface area, full-thickness, dorsal scald burn. Only one mouse in the burned group (5%) had evidence of C. albicans in the liver at the time the mice were killed. No dissemination was observed in sham-burned animals. When mice were immunosuppressed with cyclophosphamide, an increased incidence of gastrointestinal tract dissemination was noted in burned (31%) and sham-burned (23%) mice; however, only 3 days after burn was there a significant difference in dissemination between burned and sham-burned mice (p less than 0.02). This corresponded to the day of severest neutropenia in response to cyclophosphamide treatment. The results of the study indicate that C. albicans can disseminate from the gastrointestinal tract in response to thermal injury, but a significant suppression of the immune response must occur for the event to be commonplace.

Thrombus formation in lymphatic vessels associated with Brugia malayi.

Lymph thrombi within affected afferent lymphatic vessels of cats infected with Brugia malayi were examined by scanning electron microscopy. Thrombi were made up of alternating layers of fibrin strands and cells, many of which were intact erythrocytes. The endothelial lining of the vessel wall near the site of thrombus attachment showed transition from normal endothelial cells to a flattened syncytium in which individual endothelial cells could not be distinguished. Imprints of cells, including erythrocytes, were visible in the vessel wall at the point of thrombus attachment. Damage to the endothelial lining may be a factor in the initiation of thrombus formation.

Effect of preexisting inhalation injury on response to bacteremia in sheep.

Inhalation injury increases the likelihood of sepsis. We tested the hypothesis that preexisting inhalation injury would diminish bacterial clearance across the pulmonary vasculature and induce greater hemodynamic response. Live Pseudomonas aeruginosa were infused centrally for one hour in three groups of awake sheep. Inh + Ps (n = 10), with a seven to 10-day-old inhalation injury; Ps-LOW (n = 8) both received 10(7) Ps/min; and Ps-HI (n = 9) received 5 x 10(7) Ps/min. for one hour. Pulmonary hypertension was more severe in Ps-HI and Inh + Ps. A hyperdynamic response with high cardiac index and low mean arterial pressure developed in Inh + Ps and Ps-HI from six to 18 hr, while Ps-LOW, only the cardiac index was elevated at six to eight hr. The Inh + Ps and Ps-LOW groups had equivalent pulmonary artery and aortic bacterial levels, while Ps-HI had levels approximately five times higher. All groups removed bacteria efficiently in the lungs. However, preexistent inhalation injury exaggerated the pulmonary and systemic hemodynamic response.

Prospective study on the effect of shirt sleeves and ties on the transmission of bacteria to patients.

Costs associated with hospital-acquired infections lead to policies aimed at decreasing their incidence. Clothing restrictions are often implemented in response, but they are based on little scientific evidence. This study is a prospective, controlled investigation of the effect of shirt sleeves and ties on the transmission of bacteria from doctors to patients. Results show that wearing an unsecured tie results in greater transmission, but that sleeve length does not affect transmission rate. The design is a possible model for further controlled experiments to fill the evidence gap regarding the transmission of micro-organisms from healthcare workers to patients.

Effect of piliation on Klebsiella pneumoniae infection in rat bladders.

The possible role of pili in the pathogenesis of urinary tract infection caused by Klebsiella pneumoniae was investigated in a rat model of cystitis by utilizing piliated- and nonpiliated-phase organisms derived from a single parent strain. Bladder surfaces were examined for evidence of infection by scanning electron microscopy. In animals infected with piliated-phase organisms, foci of infection were evident in the majority of bladders examined. Rat bladders associated with nonpiliated-phase bacteria showed little evidence of infection. The ability of methyl-D-mannoside, a known inhibitor of pilus-mediated adherence to mammalian cells, to protect the bladder surface from colonization was also tested. The results showed a significant decrease in the ability of piliated-phase K. pneumoniae to establish infection in bladders. These observations suggest that pili may play an integral role in the ability of K. pneumoniae to cause urinary tract infections by mediating the attachment of the bacteria to the uroepithelial surface.