Integronlike structures in Campylobacter spp. of human and animal origin

Resistance to antimicrobial agents used to treat severe Campylobacter spp. gastroenteritis is increasing worldwide. We assessed the antimicrobial resistance patterns of Campylobacter spp. isolates of human and animal origin. More than half (n = 32) were resistant to sulphonamide, a feature known to be associated with the presence of integrons. Analysis of these integrons will further our understanding of Campylobacter spp. epidemiology.

Beta3-integrin-deficient mice are a model for Glanzmann thrombasthenia showing placental defects and reduced survival

beta3 integrins have been implicated in a wide variety of functions, including platelet aggregation and thrombosis (alphaIIbbeta3) and implantation, placentation, angiogenesis, bone remodeling, and tumor progression (alphavbeta3). The human bleeding disorder Glanzmann thrombasthenia (GT) can result from defects in the genes for either the alphaIIb or the beta3 subunit. In order to develop a mouse model of this disease and to further studies of hemostasis, thrombosis, and other suggested roles of beta3 integrins, we have generated a strain of beta3-null mice. The mice are viable and fertile, and show all the cardinal features of GT (defects in platelet aggregation and clot retraction, prolonged bleeding times, and cutaneous and gastrointestinal bleeding). Implantation appears to be unaffected, but placental defects do occur and lead to fetal mortality. Postnatal hemorrhage leads to anemia and reduced survival. These mice will allow analyses of the other suggested functions of beta3 integrins and we report that postnatal neovascularization of the retina appears to be beta3-integrin-independent, contrary to expectations from inhibition experiments.

Double fluorescent-amplification refractory mutation detection (dF-ARMS) of the factor V Leiden and prothrombin mutations

Simultaneous fluorescent [F] detection of the factor V Leiden (G1691A) and the prothrombin 3'-untranslated region (G20210A) mutations were performed in a single tube polymerase chain reaction (PCR). Amplification refractory mutation detection system (ARMS) formed the basis of this assay design. Fluorescent-labelled primers incorporated into amplicons during the reaction facilitated detection directly by GeneScan analysis without further manipulation. To test the efficacy of this double [F]-ARMS (dF-ARMS) method, 48 patients with unexplained thrombotic tendencies were investigated for their factor V Leiden and prothrombin genotypes. These results corresponded exactly with data achieved using the more conventional methods of restriction fragment length polymorphism (RFLP)-PCR and direct DNA sequencing. Three out of the 48 patients in this group were found to be compound heterozygotes.

Extensive vasculogenesis, angiogenesis, and organogenesis precede lethality in mice lacking all alpha v integrins

alphav integrins have been implicated in many developmental processes and are therapeutic targets for inhibition of angiogenesis and osteoporosis. Surprisingly, ablation of the gene for the alphav integrin subunit, eliminating all five alphav integrins, although causing lethality, allows considerable development and organogenesis including, most notably, extensive vasculogenesis and angiogenesis. Eighty percent of embryos die in mid-gestation, probably because of placental defects, but all embryos develop normally to E9.5, and 20% are born alive. These liveborn alphav-null mice consistently exhibit intracerebral and intestinal hemorrhages and cleft palates. These results necessitate reevaluation of the primacy of alphav integrins in many functions including vascular development, despite reports that blockade of these integrins with antibodies or peptides prevents angiogenesis.

Mutation of E2f-1 suppresses apoptosis and inappropriate S phase entry and extends survival of Rb-deficient mouse embryos

Mice mutant for the Rb tumor suppressor gene die in mid-gestation with defects in erythropoiesis, cell cycle control, and apoptosis. We show here that embryos mutant for both Rb and its downstream target E2f-1 demonstrate significant suppression of apoptosis and S phase entry in certain tissues compared to Rb mutants, implicating E2f-1 as a critical mediator of these effects. Up-regulation of the p53 pathway, required for cell death in these cells in Rb mutants, is also suppressed in the Rb/E2f-1 double mutants. However, double mutants have defects in cell cycle regulation and apoptosis in some tissues and die at approximately E17.0 with anemia and defective skeletal muscle and lung development, demonstrating that E2F-1 regulation is not the sole function of pRB in development.

Mice heterozygous for a mutation at the Nf2 tumor suppressor locus develop a range of highly metastatic tumors

A role for the membrane/cytoskeleton interface in the development and progression of cancer is established, yet poorly understood. The neurofibromatosis type II (NF2) tumor suppressor gene encodes a member of the ezrin/radixin/moesin (ERM) family of membrane/cytoskeleton linker proteins thought to be important for cell adhesion and motility. We report that in contrast to the narrow spectrum of benign tumors in human NF2 patients, Nf2 heterozygous mice develop a variety of malignant tumors. Using the fact that Nf2 is linked to the p53 tumor suppressor locus in the mouse we have also investigated the effects of genetic linkage of cancer-predisposing mutations on tumorigenesis and examined the genetic pathway to tumor formation involving Nf2 loss. Importantly, we observed a very high rate of metastasis associated with Nf2 deficiency, with or without loss of p53 function, and we provide experimental evidence supporting a role for Nf2 loss in metastatic potential. Together, our results suggest an important role for the NF2 tumor suppressor, and perhaps the ERM family in tumor formation and metastasis.

Comprehensive analysis of organic ligands in whole root exudates using nuclear magnetic resonance and gas chromatography-mass spectrometry

Root exudates in the rhizosphere are vital to the normal life cycle of plants. A key factor is phytometallophores, which function in the nutritional acquisition of iron and zinc and are likely to be important in the uptake of pollutant metals by plants. Unraveling the biochemistry of these compounds is tedious using traditional analyses, which also fall short in providing the overall chemical composition or in detecting unknown or unexpected organic ligands in the exudates. Here, we demonstrate a comprehensive analysis of the exudate composition directly by 1H and 13C multidimensional NMR and silylation GC-MS. The advantages are (a) minimal sample preparation, with no loss of unknown compounds, and reduced net analysis time; (b) structure-based analysis for universal detection and identification; and (c) simultaneous analysis of a large number of constituents in a complex mixture. Using barley root exudates, a large number of common organic and amino acids were identified. Three derivatives of mugineic acid phytosiderophores were also determined, the major one being 3-epihydroxymugineic acid, for which complete 1H and 13C NMR assignments were obtained. Quantification of all major components using these methods revealed a sevenfold increase in total exudation under moderate iron deficiency, with 3-epihydroxymugineic acid comprising approximately 22% of the exudate mixture. As iron deficiency increased, total quantities of exudate per gram of root remained unchanged, but the relative quantity of carbon allocated to phytosiderophore increased to approximately 50% of the total exudate in response to severe iron deficiency.

Successful treatment of infantile hemangiomas with interferon-alpha-2b

PURPOSE

Hemangiomas are benign tumors occurring in 10% of infants. A small percentage are complicated by blockage of vital structures, consumptive coagulopathy, or heart failure, resulting in a mortality of -20% of patients with complications. Here, we describe four infants with complicated hemangiomas responding to interferon-alpha-2b therapy.

PATIENTS AND METHODS

Four children with hemangiomas were treated with interferon-alpha-2b for complicating heart failure (1), visual impairment (2), or coagulopathy (1). Patients received interferon-alpha-2b alone or in conjunction with corticosteroid therapy over 2 to 9 months. Imaging studies and urinary basic fibroblast growth factor (bFGF) levels were used to monitor treatment response.

RESULTS

Three of four patients demonstrated involution of the hemangiomas with improvement in their coagulopathy or visual impairment. The fourth patient expired due to cardiac complications despite radiologic evidence of hemangioma involution. Side effects associated with interferon-alpha-2b treatment included elevated transaminases (2) and leukocytosis (2), which resolved upon completion of therapy. One patient developed mild gross motor delay (1), which improved after cessation of therapy. Decreased urinary bFGF levels correlated with hemangioma involution.

CONCLUSION

Interferon-alpha-2b therapy is an effective, well-tolerated treatment for complicated hemangiomas. Measurement of urinary bFGF levels may provide an objective method for monitoring treatment response.

The Genome Sequence DataBase version 1.0 (GSDB): from low pass sequences to complete genomes

The Genome Sequence DataBase (GSDB) has completed its conversion to an improved relational database. The new database, GSDB 1.0, is fully operational and publicly available. Data contributions, including both original sequence submissions and community annotation, are being accomplished through the use of a graphical client-server interface tool, the GSDB Annotator, and via GIO (GSDB Input/Output) files. Data retrieval services are being provided through a new Web Query Tool and direct SQL. All methods of data contribution and data retrieval fully support the new data types that have been incorporated into GSDB, including discontiguous sequences, multiple sequence alignments, and community annotation.

The Genome Sequence DataBase (GSDB): meeting the challenge of genomic sequencing

The genome sequence database (GSDB) is a complete, publicly available relational database of DNA sequences and annotation maintained by the National Center for Genome Resources (NCGR) under a Cooperative Agreement with the US Department of Energy (DOE). GSDB provides direct, client- server access to the database for data contributions, community annotation and SQL queries. The GSDB Annotator, a multi-platform graphic user interface, is freely available. Automatically updated relational replicates of GSDB are also freely available.

Peritoneal migration of an abdominally implanted epicardial pacemaker: a cause of intestinal obstruction

We report the case of a 10-year-old child with an abdominally implanted epicardial pacemaker that eroded through the peritoneum and migrated to an intraperitoneal location, resulting in partial and then complete intestinal obstruction. This potentially life-threatening complication should be considered when a patient with an abdominally implanted pacemaker presents with abdominal pain.

The delta (argF-lacZ)205(U169) deletion greatly enhances resistance to hydrogen peroxide in stationary-phase Escherichia coli

In this study, we demonstrate that a strain bearing the delta (argF-lacZ)205(U169) deletion exhibits a high level of resistance to hydrogen peroxide compared with its undeleted parent. Our initial investigation of the mechanism behind the observed differences in peroxide resistance when parent and mutant strains are compared indicates that the parent strain carries a region near argF that is responsible for the H2O2-sensitive phenotype, which we have named katC. The H2O2 resistance phenotype of the delta katC [delta (argF-lacZ)205(U169)] mutant strain can be duplicated by Tn9 insertion in a specific locus (katC5::Tn9) which maps near argF. The increased H2O2 resistance of the delta katC and katC5::Tn9 mutant strains can be seen only when cells are grown to stationary phase; exponential-phase cells are unaffected by the presence or absence of katC. This H2O2 resistance mechanism requires functional katE and katF genes, which suggests that the mechanism of H2O2 resistance may involve the activity of the stationary-phase-specific catalase HPII. Cloning, DNA sequencing, and analysis of the katC5::Tn9 insertion allele in comparison with its parent allele implicate two insertion elements, IS1B and IS30B, and suggest that their presence sensitizes parent cells to H2O2.

Use of extracorporeal life support in patients with congenital heart disease

OBJECTIVES

To review a large experience with extracorporeal life support in patients with congenital heart disease. To determine the major causes of mortality and morbidity in order to improve the results of using this technology in this patient population.

DESIGN

Retrospective chart review.

PATIENTS

Twenty-five patients between the ages of 1 day and 8 yrs. These patients had congenital heart disease and were clinically felt to be at high risk for death caused by cardiac failure or by respiratory failure complicated by congenital heart disease.

INTERVENTIONS

All patients in this report were placed on extracorporeal life support to allow recovery of myocardial or pulmonary function.

MEASUREMENTS AND MAIN RESULTS

Of these 25 patients, 52% were weaned from bypass support and 40% survived to discharge. Patients who were not weaned from extracorporeal life support characteristically suffered from irreversible neurologic injury, multiple organ failure, or bleeding complications. Only one patient died of irreversible cardiac failure.

CONCLUSIONS

Extracorporeal life support can be useful in supporting patients with congenital heart disease with life-threatening cardiac or pulmonary failure. Improvements in limiting neurologic and bleeding complications may lead to improvements in the use of extracorporeal life support for this indication. However, prospective, randomized studies are needed to appreciate the role of extracorporeal life support in these patients.

Prolonged extracorporeal life support of pediatric and adolescent cardiac transplant patients

Options for mechanical support of pediatric patients with severe heart failure who are awaiting transplantation or have undergone transplantation are limited. This report examines 3 patients placed on extracorporeal life support (ECLS) while awaiting transplantation and 3 patients who underwent transplantation and suffered subsequent heart failure due to rejection or postoperative myocardial dysfunction. The overall survival rate was 2 of 6. The 2 surviving patients had a failing transplanted heart. There were no survivors among the patients placed on ECLS as a bridge to transplantation. In each case a contraindication to transplantation developed before a donor heart could be obtained. The mean time of ECLS support was 147.5 hours (range, 70 to 370 hours). The ECLS circuit did not affect cyclosporin levels or antirejection therapy. Extracorporeal life support can be used to support pediatric cardiac transplant patients with biventricular failure due to acute rejection or postoperative dysfunction. Although the results have been discouraging, ECLS may still have a role as a bridge to transplantation. However, complications can develop during ECLS that may preclude transplantation.

Hepatitis B virus infection in Northern Ireland 1970-1987

In the 18 years between 1970 and 1987, 504 patients were found to have hepatitis B surface antigen (HBsAg) in their blood. Acute hepatitis was present in 184 patients and six died (3.3%). The annual incidence of acute hepatitis B virus infection in Northern Ireland was about one-quarter that of England and Wales. A decrease in acute infection occurred in 1986-87, while in England and Wales acute infection has fallen by more than half since the peak in 1984. Hepatitis B virus infection in health care staff and patients in high risk groups were reviewed: 32% were in those of foreign origin or who had known foreign contacts. In blood donors there was a marked fall in incidence of hepatitis B surface antigen carriage from 1982 onwards: the incidence in antenatal patients and those screened for rubella antibody (mainly females) was half that of new blood donors in 1972-81. Carrier rates in blood donors and antenatal patients were less than those from other parts of the United Kingdom. All indices show that Northern Ireland has a lower incidence of hepatitis B virus infection than the rest of the United Kingdom.

Family stress after pediatric heart transplantation

Parents of ten children who underwent cardiac transplantation at the authors' institution participated in this study to evaluate the effect of heart transplantation on the family. Parents completed the Hymovich Chronicity Impact and Coping Instrument (CICI) and/or the Feetham Family Function Survey (FFFS) 3 to 24 months (mean, 8.4 months) after the transplant. Results indicate that parents face significant psychological and social stresses after their child's heart transplantation related to (1) the uncertainty of the child's future health and well-being, (2) role strain, (3) social isolation, and (4) financial burdens. Recommendations for nursing practice are suggested.

Paradoxical hypertension after repair of coarctation of the aorta in children: balloon angioplasty versus surgical repair

The incidence and possible causes of paradoxical hypertension were evaluated in eight children who underwent balloon dilatation and seven children who underwent surgical repair of coarctation of the aorta. Both procedures resulted in a significant reduction in the coarctation gradient. Both systolic and diastolic blood pressures increased in the surgical group after repair, whereas systolic pressures decreased and diastolic pressures remained unchanged after balloon angioplasty. In the surgical group, but not in the balloon angioplasty group, plasma catecholamines and plasma renin activity rose during the first 2 days after relief of the coarctation. The data presented in this report support the hypothesis that the sympathetic nervous system and the renin angiotensin system are important mediators of the paradoxical hypertension that occurs after surgical repair of coarctation. Furthermore, balloon angioplasty of coarctation of the aorta does not stimulate either system and thus paradoxical hypertension is not a complication of this procedure.

Post-transfusion hepatitis: a problem in Northern Ireland?

A retrospective analysis of post-transfusion hepatitis reported to us from 1980 through 1984 revealed 16 patients. We believe that this apparently low incidence is due to lack of notification and make a case for direct notification to us of any suspected cases. Disqualification of implicated blood donors is of prime importance in prevention of transfusion-associated hepatitis.

Lamotrigine (BW430C), a potential anticonvulsant. Effects on the central nervous system in comparison with phenytoin and diazepam

Twelve healthy male volunteers received phenytoin 0.5 and 1 g, lamotrigine (a new anticonvulsant) 120 and 240 mg, diazepam 10 mg and placebo orally in a double-blind, cross-over, randomized trial. Maximum drug concentrations at 4 h, measured in plasma were 11.5 +/- 2.2 micrograms ml-1 for phenytoin and 2.7 +/- 0.4 micrograms ml-1 for lamotrigine. These levels were in the therapeutic range for phenytoin and the putative therapeutic range for lamotrigine. Side effects after diazepam (mainly sedation) and phenytoin (mainly unsteadiness) differed markedly from lamotrigine which produced no important side effects. Subjective effects as measured by visual analogue scales were caused by phenytoin and diazepam but not by lamotrigine. Diazepam impaired eye movements, adaptive tracking and body sway. Phenytoin impaired adaptive tracking, increased body sway and impaired smooth pursuit eye movement. Lamotrigine produced only a possible slight increase in body sway. There were significant correlations between performance and saliva levels of phenytoin and diazepam. It was concluded that the tests used were suitable for monitoring CNS effects of anticonvulsants and that lamotrigine possibly could have a more favourable CNS side effect profile than phenytoin.