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A comparative proteomic approach is used to analyze the extracellular proteomes of enterohemorrhagic (EHEC) and enteropathogenic (EPEC) Escherichia coli in order to give insight into the pathogenesis and divergence of these two emerging pathogens. The results show that proteomics is a powerful platform technology for accelerating the understanding of EPEC and EHEC pathogenesis and identifying markers for laboratory diagnoses of these pathogens.

Four black patients, all with sickle trait (SA), developed transient open-angle glaucoma with blood in Schlemm's canal. In 3 patients the condition followed blunt trauma, while in the fourth no antecedent trauma was described. The intraocular pressure became normal in all 4 cases with the resolution of the haemorrhage from the trabecular meshwork and Schlemm's canal. [ABSTRACT FROM PUBLISHER]

Introduction: Residential summer camps are popular among Canadian families. Campers are exposed to new, unfamiliar environments and engage in activities that may pose increased risk of injury. This study identifies the occurrence and management of musculoskeletal and head injuries at a Canadian residential summer camp., Methods: This study was a three-year prospective observational cohort study, at a six-week Canadian residential summer camp. There were 1,388 residents, consisting of 51,546 camp days (CD). Injury data were collected by residential summer camp staff and confirmed by onsite medical professionals prior to being recorded in a secure database. Injuries were included if it was a musculoskeletal or head injury that occurred while engaged in a camp activity on or offsite, that necessitated medical attention, and that required removal or restriction from their normal camp routine for a minimum of 4 hours., Results: There were 154 injuries, resulting in an incidence of 2.99 injuries per 1000 CD. Injuries were reported during scheduled activities (1.46/1000 CD) and free time (1.20/1000 CD). Sports was the most common activity during which injury occurred in all age groups (1.07/1000 CD), where males were injured twice as often as females. 65% of injuries occurred while under staff supervision. The lower extremity was the most affected body part (1.59/1000 CD). Sprains and strains accounted for 1.69 injuries/1000 CD. 83% of injuries were classified as significant and 89% of injuries were treated on-site. Over-the-counter analgesics were provided in 62% of senior camper injuries and 46% of junior camper and staff injuries., Conclusion: Most injuries in the residential camp setting are mild. Ensuring appropriate non-pharmacologic measures in addition to adequate analgesia may help shorten return to play., Competing Interests: The authors have declared that no competing interests exist., (Copyright © 2022, Freedman et al.)

MicroRNA-144 is a cytoprotective miRNA. Our previous study showed that miR-144 provides potent acute cardioprotection in an ischemia/reperfusion injury model. This study was performed to further assess whether miR-144 improves post-MI remodeling in a non-reperfused myocardial infarction (MI) model. C57BL/6 mice were subjected to MI by permanent left anterior descending artery (LAD) ligation. miR-144 was delivered by intravenous injections of 8 mg/kg, 16 mg/kg, or 32 mg/kg at day 0, day 1, day 3, and then a similar dose given once every 3 days, until day 28 after MI. Cardiac function was evaluated using echocardiography. At the end of the study, heart function was also evaluated using a pressure volume catheter. The percentage of the length of the infarct scar on the left ventricle (LV) circumferential length was calculated for heart each section. The miR-144 KO mice showed a worse heart failure phenotype with ventricular dilation and impaired contractility after LAD ligation. Ischemia decreased miR-144 levels, and the miR-144 level was restored to baseline by administration of intravenous miR-144. Cy3-labeled miR-144 was localized to the infarct and border zone, and was taken up by cardiomyocytes and macrophages. In miR-144-treated groups, at 28 days MI size was significantly reduced, and cardiac function was improved [LV fractional shortening, end-systolic volume (µL), end-diastolic volume (µL), ejection fraction (%), dP/dt max (mmHg/s), dP/dt min (mmHg/s), Tau (ms)], compared with controls (p < 0.01). This beneficial effect was associated with reduced border zone fibrosis, inflammation and apoptosis, these effects were associated with significant changes in autophagy signaling. Intravenous miR-144 has potent effects on post-MI remodeling. These findings suggest that miR-144 has potential as a therapeutic agent after MI.

Severely comminuted olecranon fractures, for which elbow stability becomes the main goal of surgery, remain a challenge for surgeons. We conducted a study to determine the percentage loss of articular surface at which a bridge plating (BP) construct becomes too unstable and an acute shortening (AS) construct is required. The olecranon process of 8 fresh-frozen cadaveric upper limbs was serially resected. At each resection, the simulated fracture was fixed first with BP and then with AS. Stability was tested by performing valgus and varus stress tests at various angles under fluoroscopy. As many as 6 serial resections were made on the cadaveric models. Maximum resection was 88%. The ulnohumeral joint remained stable to valgus and varus stress at all resections for both BP and AS. The elbow joint lost a significant amount of flexion with AS above 20% resection. The ulnohumeral joint can tolerate substantial loss of articular surface in the olecranon before becoming unstable. In this study, range of motion was preserved more with the BP construct than with the AS construct. The presented data may be considered when approaching a severely comminuted olecranon fracture in which the articular surface cannot be reconstructed., Competing Interests: Authors’ Disclosure Statement: The authors report no actual or potential conflict of interest in relation to this article.

Most effector proteins of bacterial type III secretion (T3S) systems require chaperone proteins for translocation into host cells. Such effectors are bound by chaperones in a conserved and characteristic manner, with the chaperone-binding (Cb) region of the effector wound around the chaperone in a highly extended conformation. This conformation has been suggested to serve as a translocation signal in promoting the association between the chaperone-effector complex and a bacterial component required for translocation. We sought to test a prediction of this model by identifying a potential association site for the Yersinia pseudotuberculosis chaperone-effector pair SycE-YopE. We identified a set of residues in the YopE Cb region that are required for translocation but are dispensable for expression, SycE binding, secretion into the extrabacterial milieu, and stability in mammalian cells. These residues form a solvent-exposed patch on the surface of the chaperone-bound Cb region, and thus their effect on translocation is consistent with the structure of the chaperone-bound Cb region serving as a signal for translocation.

Enteropathogenic Escherichia coli (EPEC) causes severe diarrhea in young children. Essential for colonization of the host intestine is the LEE pathogenicity island, which comprises a cluster of operons encoding a type III secretion system and related proteins. The LEE1 operon encodes Ler, which positively regulates many EPEC virulence genes in the LEE region and elsewhere in the chromosome. We found that Ler acts as a specific autorepressor of LEE1 transcription. We further show that Ler specifically binds upstream of the LEE1 operon in vivo and in vitro. A comparison of the Ler affinities to different DNA regions suggests that the autoregulation mechanism limits the steady-state level of Ler to concentrations that are just sufficient for activation of the LEE2 and LEE3 promoters and probably other LEE promoters. This mechanism may reflect the need of EPEC to balance maximizing the colonization efficiency by increasing the expression of the virulence genes and minimizing the immune response of the host by limiting their expression. In addition, we found that the autoregulation mechanism reduces the cell-to-cell variability in the levels of LEE1 expression. Our findings point to a new negative regulatory circuit that suppresses the noise and optimizes the expression levels of ler and other LEE1 genes.

Enteropathogenic Escherichia coli (EPEC) are extracellular pathogens that colonize mucosal surfaces of the intestine via formation of attaching and effacing (A/E) lesions. The genes responsible for induction of the A/E lesions are located on a pathogenicity island, termed the locus of enterocyte effacement (LEE), which encodes the adhesin intimin and the type III secretion system needle complex, translocator and effector proteins. One of the major EPEC translocator proteins, EspA, forms a filamentous conduit along which secreted proteins travel before they arrive at the translocation pore in the plasma membrane of the host cell, which is composed of EspB and EspD. Prior to secretion, many type III proteins, including translocators, are maintained in the bacterial cytoplasm by association with a specific chaperone. In EPEC, chaperones have been identified for the effector proteins Tir, Map and EspF, and the translocator proteins EspD and EspB. In this study, CesAB (Orf3 of the LEE) was identified as a chaperone for EspA and EspB. Specific CesAB-EspA and CesAB-EspB protein interactions are demonstrated. CesAB was essential for stability of EspA within the bacterial cell prior to secretion. Furthermore, a cesAB mutant failed to secrete EspA, as well as EspB, to assemble EspA filaments, to induce A/E lesion following infection of HEp-2 cells and to adhere to, or cause haemolysis of, erythrocytes.

The flagellar apparatus consists of components that function as a type III secretion system (TTSS). Enteropathogenic and enterohaemorrhagic E. coli (EPEC and EHEC, respectively) produce an additional TTSS, which is involved in virulence via the translocation of effector proteins into infected host cells. This system is encoded by the locus of enterocyte effacement (LEE). The authors observed that EPEC and EHEC grown in Dulbecco's modified Eagle's medium to the mid- and late-exponential growth phase at 37 degrees C are non-motile. At the same time these conditions trigger the expression of the LEE-encoded TTSS. Furthermore, it was found that EPEC with an inactivated ihfA, which encodes the IHFalpha subunit of the integration host factor (IHF), becomes hyperflagellated and motile. Similar hypermotility was seen upon inactivation of the ihfA of EHEC strains. IHF-mediated repression of the EPEC flagella involves down-regulation of flhDC, which encodes a positive regulator of the flagellar regulon. IHF indirectly mediates flhDC repression, via a putative EPEC-unique regulator which is not encoded by LEE.

Objective: To evaluate rates and causes of visual loss among patients with acquired immunodeficiency syndrome (AIDS) and cytomegalovirus (CMV) retinitis before widespread availability of highly active antiretroviral therapy (HAART)., Methods: Data from 681 patients with AIDS and newly diagnosed or relapsed CMV retinitis who enrolled in 3 clinical trials conducted by the Studies of Ocular Complications of AIDS (SOCA) Research Group (between 1990 and 1996) were combined to evaluate the rates and causes of visual loss. Visual acuity and visual field (Goldmann visual fields) losses were evaluated., Results: The rates of visual loss in eyes with CMV retinitis were substantial in all 3 clinical trials, ranging from 51.7 to 97.7 events per 100 eye-years for loss of visual acuity to worse than 20/40 and 18.9 to 49.1 events per 100 eye-years for loss of visual acuity to 20/200 or worse. The 2 major causes of visual loss were retinitis, involving either the macula or the optic nerve, and retinal detachment. After 1992, visual outcomes improved significantly. Antiretroviral therapy was associated with a 30% reduction in the risk of visual acuity loss (relative risk, 0.70; P =.02)., Conclusions: In the pre-HAART era, visual morbidity was substantial. However, there was a secular trend for improved outcomes. The principal causes of visual loss were CMV involvement of the posterior retina and retinal detachment.

Enteropathogenic Escherichia coli (EPEC) causes severe diarrhoea in young children. The locus of enterocyte effacement (LEE) pathogenicity island comprises a cluster of operons encoding a type III secretion system and related proteins that are associated with EPEC virulence. The LEE1 operon encodes Ler that positively regulates the LEE2, LEE3, LEE4, LEE5 and espG transcriptional units. The LEE operons are repressed at 27 degrees C and expressed at 37 degrees C. This paper describes a regulatory cascade of the thermoregulation of LEE operons. LEE1 including ler is repressed by H-NS at 27 degrees C but not at 37 degrees C. In contrast, the expression of the LEE2, LEE3, LEE4, LEE5 and espG transcriptional units is repressed by H-NS at both 27 degrees C and 37 degrees C. Upon shifting the culture temperature from 27 degrees C to 37 degrees C, Ler is synthesized and in turn activates the expression of LEE2, LEE3, LEE4 and espG by releasing the H-NS mediated repression. In the case of LEE5, Ler acts both by alleviating the H-NS mediated repression and by an additional mechanism, as yet to be defined.

Valganciclovir, an oral prodrug of the anti-cytomegalovirus (CMV) agent ganciclovir, was evaluated in a single-arm open-label safety study. AIDS patients (median CD4 lymphocyte count of 140 cells/microL) with treated CMV retinitis (N = 212) received 900-mg once-daily valganciclovir maintenance therapy with courses of 900-mg twice-daily valganciclovir induction therapy as needed to treat progression. After a median treatment duration of 372 days, the adverse event profile was similar to that reported for intravenous (IV) and oral ganciclovir. Adverse event rates of note were diarrhea (35%), nausea (23%), fever (18%), neutropenia (absolute neutrophil count <500 cells/microL) (10%), and anemia (hemoglobin <8.0 g/dL) (12%). Consistent with prior treatment studies of oral ganciclovir, IV catheter-related adverse events were uncommon (6%) and lower than previously reported for IV ganciclovir. The mortality rate was 0.072 deaths per patient-year. Progression of CMV retinitis occurred in 17% of patients during the study treatment period, usually in association with a low CD4 cell count. Other than a higher than expected frequency of oral candidiasis (17%), no clinical toxicities or laboratory abnormalities occurred during treatment with valganciclovir that have not been observed during treatment with ganciclovir.

Enteropathogenic Escherichia coli (EPEC) uses a type III secretion system (TTSS) to inject effector proteins into the plasma membrane and cytosol of infected cells. To translocate proteins, EPEC, like Salmonella and Shigella, is believed to assemble a macromolecular complex (type III secreton) that spans both bacterial membranes and has a short needle-like projection. However, there is a special interest in studying the EPEC TTSS owing to the fact that one of the secreted proteins, EspA, is assembled into a unique filamentous structure also required for protein translocation. In this report we present electron micrographs of EspA filaments which reveal a regular segmented substructure. Recently we have shown that deletion of the putative structural needle protein, EscF, abolished protein secretion and formation of EspA filaments. Moreover, we demonstrated that EspA can bind directly to EscF, suggesting that EspA filaments are physically linked to the EPEC needle complex. In this paper we provide direct evidence for the association between an EPEC bacterial membrane needle complex and EspA filaments, defining a new class of filamentous TTSS.

Lrp (leucine-responsive regulatory protein) plays a global regulatory role in Escherichia coli, affecting expression of dozens of operons. Numerous lrp-related genes have been identified in different bacteria and archaea, including asnC, an E. coli gene that was the first reported member of this family. Pairwise comparisons of amino acid sequences of the corresponding proteins shows an average sequence identity of only 29% for the vast majority of comparisons. By contrast, Lrp-related proteins from enteric bacteria show more than 97% amino acid identity. Is the global regulatory role associated with E. coli Lrp limited to enteric bacteria? To probe this question we investigated LrfB, an Lrp-related protein from Haemophilus influenzae that shares 75% sequence identity with E. coli Lrp (highest sequence identity among 42 sequences compared). A strain of H. influenzae having an lrfB null allele grew at the wild-type growth rate but with a filamentous morphology. A comparison of two-dimensional (2D) electrophoretic patterns of proteins from parent and mutant strains showed only two differences (comparable studies with lrp(+) and lrp E. coli strains by others showed 20 differences). The abundance of LrfB in H. influenzae, estimated by Western blotting experiments, was about 130 dimers per cell (compared to 3,000 dimers per E. coli cell). LrfB expressed in E. coli replaced Lrp as a repressor of the lrp gene but acted only to a limited extent as an activator of the ilvIH operon. Thus, although LrfB resembles Lrp sufficiently to perform some of its functions, its low abundance is consonant with a more local role in regulating but a few genes, a view consistent with the results of the 2D electrophoretic analysis. We speculate that an Lrp having a global regulatory role evolved to help enteric bacteria adapt to their ecological niches and that it is unlikely that Lrp-related proteins in other organisms have a broad regulatory function.

Enteropathogenic Escherichia coli (EPEC) elicit changes in host cell morphology and cause actin rearrangement, a phenotype that has commonly been referred to as attaching/effacing (AE) lesions. The ability of EPEC to induce AE lesions is dependent upon a type III protein secretion/translocation system that is encoded by genes clustered in a 35.6 kb DNA segment, named the locus of enterocyte effacement (LEE). We used transcriptional fusions between the green fluorescent protein (gfp) reporter gene and LEE genes rorf2, orf3, orf5, escJ, escV and eae, together with immunoblot analysis with antibodies against Tir, intimin, EspB and EspF, to analyse the genetic regulation of the LEE. The expression of all these LEE genes was strictly dependent upon the presence of a functional integration host factor (IHF). IHF binds specifically upstream from the ler (orf1) promoter and appears to activate expression of ler, orf3, orf5 and rorf2 directly. The ler-encoded Ler protein was involved in activating the expression of escJ, escV, tir, eae, espB and espF. Expression of both IHF and Ler was needed to elicit actin rearrangement associated with AE lesions. In conclusion, IHF directly activates the expression of the ler and rorf2 transcriptional units, and Ler in turn mediates the expression of the other LEE genes.

Purpose: To describe three women with narrow-angle glaucoma who had transient blurred vision during sexual arousal., Method: Case reports., Results: Three women, aged 37, 45, and 55 years, were seen with bilateral narrow-angle glaucoma and were treated with bilateral laser iridotomy. In each patient, additional surgery was required to control the glaucoma. After establishing a rapport with her physician, each patient described transient blurred vision, from a few minutes to several hours in duration, which began during sexual arousal. This symptom resolved after peripheral iridotomy and, in one patient, after laser iridoplasty., Conclusion: The association of transient blurred vision with sexual activity may delay presentation of patients with symptomatic narrow-angle glaucoma.

Although SCD is relatively uncommon, its psychosocial impact is devastating. This article has reviewed the potential causes of SCD in infants, children, and adolescents. Many patients who die from SCD have identifiable cardiac disease and are known to have been at risk; however, the existence of other cardiac abnormalities, such as hypertrophic cardiomyopathy or long QT syndrome, may not be known, and SCD may be the first symptom. The authors' contention is that many of the patients in this latter group (e.g., patients who have hypertrophic cardiomyopathy or LQLTS but who have no symptoms) can be screened with a careful, accurate, and detailed history, including family history and review of systems, and physical examination. Any patient with a positive family history, positive review of systems, or positive physical examination should receive further in-depth evaluation, such as an ECG and echocardiogram. These studies permit the detection of most, if not all, of the entities potentially associated with SCD in the pediatric population.

Anomalous origin of the right coronary artery from the left sinus of Valsalva is a rare congenital defect that can be difficult to diagnose by echocardiography. We describe an infant with a ventricular septal defect that was diagnosed prospectively by transthoracic echocardiography as an anomalous origin of the right coronary artery from the left sinus of Valsalva. Subcostal imaging and Doppler color flow mapping were instrumental in the echocardiographic diagnosis of this unusual coronary abnormality.

As we enter the next millennium, we are encouraged by the progress that has been made in the care of neonates, infants, and children with heart disease. Surgical repair can be offered at an earlier age with excellent results. Diseases that were uniformly fatal in the past have improved outcomes. Research continues in the area of interventional devices such that surgical repair might be eliminated or delayed. We continue to look forward to advances in the next several years that will allow for future improvement in outcome, better quality-of-life and better long-term results.