Antigenicity and immunogenicity of phage library-selected peptide mimics of the major surface proteophosphoglycan antigens of Entamoeba histolytica

Entamoeba histolytica is the protozoan parasite responsible for intestinal amoebiasis and amoebic liver abscess, which cause significant morbidity and mortality in many countries of the world. Proteophosphoglycans (PPGs, also known as lipophosphoglycans, LPGs, or lipopeptidophosphoglycans, LPPGs) represent dominant surface components of E. histolytica. Passive immunization with a monoclonal antibody (EH5) directed against these components protected SCID mice from amoebic liver abscess, so PPGs might be regarded as vaccine candidates; however, their structure is very complex and only known in part. They are glycosylphosphatidylinositol-linked polypeptides of unknown sequence carrying glycan side-chains linked to serine residues via phosphodiester bonds. In order to identify peptide mimics of the E. histolytica PPG antigens, we screened six different phage-displayed random peptide libraries with the antibody EH5. Various peptide mimics of different length were identified and, in all the peptides, a distinct consensus sequence Gly-Thr-His-Pro-X-Leu could be identified. The phages strongly bound to the antibody, and the natural antigen inhibited binding of the phages to antibody EH5. In addition, several of the phages induced a significant immunoglobulin G response against amoebic antigens in immunized mice.     

Detection of left ventricular dysfunction after acute myocardial infarction: comparison of clinical, echocardiographic, and neurohormonal methods.

OBJECTIVE--The SAVE study showed that captopril improves mortality in patients with left ventricular dysfunction after myocardial infarction and that this benefit occurred even in patients with no clinically overt heart failure. On the basis of this, it seems important to identify correctly which patients have left ventricular dysfunction after a myocardial infarction. The objective was to compare various methods of identifying patients with left ventricular dysfunction (left ventricular ejection fraction, LVEF, < or = 40%) after acute myocardial infarction. The methods compared were echocardiography (quantitative and qualitative visual assessment), clinical evaluation (subjective assessment and three clinical score methods), and measurement of plasma concentrations of cardiac natriuretic peptide hormones (atrial and brain natriuretic peptides, ANP and BNP). DESIGN--Cross sectional study of left ventricular function in patients two to eight days after acute myocardial infarction. SETTING--Coronary care unit of a teaching hospital. PATIENTS--75 survivors of a recent myocardial infarction aged 40 to 88 with no history of cardiac failure and without cardiogenic shock at the time of entry to the study. MAIN OUTCOME MEASURES--Sensitivities and specificities of the various methods of detecting left ventricular dysfunction were calculated by comparing them with a cross sectional echocardiographic algorithm for LVEF. RESULTS--Clinical impression was poor at identifying LVEF < 40% (sensitivity 46%). Clinical scoring improved this figure somewhat (modified Peel index sensitivity 64%). Qualitative visual assessment echocardiography was a more sensitive method (sensitivity 82%) for detecting LVEF < 40%. Plasma BNP concentration was also a sensitive measure for detecting left ventricular dysfunction (sensitivity 84%) but plasma ANP concentration was much poorer (sensitivity 64%). CONCLUSION--Left ventricular dysfunction is easily and reliably detected by echocardiographic measurement of LVEF and also by a quick qualitative echocardiographic assessment but is likely to be missed by clinical assessment alone. High concentrations of plasma BNP maybe another useful indicator of left ventricular dysfunction, particularly in hospitals where not all patients can be screened by echocardiography or radionuclide ventriculography after myocardial infarction.     

Combined modality treatment of small cell carcinoma of the lung

Ninety patients with extensive and 61 with limited small cell carcinoma of the lung were treated with three courses of intravenous chemotherapy (cyclophosphamide, doxorubicin hydrochloride, and vincristine sulfate) followed by radiotherapy to intrathoracic disease, and a second three-drug oral combination consisting of lomustine, procarbazine, and methotrexate for one year. Among the 147 patients who were evaluated, 55 of 66 (83%) with limited disease and 53 of 81 (65%) with extensive disease showed response after three courses of chemotherapy. The complete response rate in patients with limited disease prior to radiotherapy was 24%, but increased to 58% when evaluated following radiotherapy. The median survival was 47 weeks for patients with limited disease and 36 weeks for those with extensive disease. A 24% two-year survival is projected for complete responders. Important prognostic factors for survival are performance status, extent of disease, and sex, with female subjects doing somewhat better than male subjects. Among patients with limited disease, 45% failed within the CNS despite the use of chemotherapeutic agents that cross the blood-brain barrier. The initial induction regimen and radiotherapy were well tolerated; the oral three-drug combination was more toxic and did not prevent CNS metastases.     

Rapid identification of donor and recipient cells after allogeneic bone marrow transplantation using specific genetic markers

The fate of the donor graft in allogeneic bone marrow transplantation, the presence of chimaerism and early relapse can be monitored by identification of the donor or recipient origin of haemopoietic cells in peripheral blood and bone marrow. We have done this by the use of highly informative locus-specific hypervariable DNA probes in two sex and blood group matched transplants. In four sex mismatched transplants the Y chromosome was identified by in situ hybridization using a biotinylated Y probe. Early engraftment by day 13 was detected in five of the six patients. Transient chimaerism occurred in half of the cases and was accompanied by the temporary appearance of the Philadelphia chromosome in one patient with chronic myeloid leukaemia without subsequent relapse. Persistence of the graft in the face of falling peripheral counts was documented in four of the six patients studied. The morphology as well as origin of the haemopoietic cells could be characterized by the Y probe analysis. In one patient, recipient lymphocytes were shown to co-exist with myeloid series of donor origin. We conclude that both techniques are highly specific, sensitive and can provide information within 24-48 h. Thus they are of value in guiding early therapeutic intervention in allogeneic transplantation.     

The Cancer Imaging Archive (TCIA): Maintaining and Operating a Public Information Repository

The National Institutes of Health have placed significant emphasis on sharing of research data to support secondary research. Investigators have been encouraged to publish their clinical and imaging data as part of fulfilling their grant obligations. Realizing it was not sufficient to merely ask investigators to publish their collection of imaging and clinical data, the National Cancer Institute (NCI) created the open source National Biomedical Image Archive software package as a mechanism for centralized hosting of cancer related imaging. NCI has contracted with Washington University in Saint Louis to create The Cancer Imaging Archive (TCIA)—an open-source, open-access information resource to support research, development, and educational initiatives utilizing advanced medical imaging of cancer. In its first year of operation, TCIA accumulated 23 collections (3.3 million images). Operating and maintaining a high-availability image archive is a complex challenge involving varied archive-specific resources and driven by the needs of both image submitters and image consumers. Quality archives of any type (traditional library, PubMed, refereed journals) require management and customer service. This paper describes the management tasks and user support model for TCIA.     

Virus species polemics: 14 senior virologists oppose a proposed change to the ICTV definition of virus species

The Executive Committee of the International Committee on Taxonomy of Viruses (ICTV) has recently decided to modify the current definition of virus species (Code of Virus Classification and Nomenclature Rule 3.21) and will soon ask the full ICTV membership (189 voting members) to ratify the proposed controversial change. In this discussion paper, 14 senior virologists, including six Life members of the ICTV, compare the present and proposed new definition and recommend that the existing definition of virus species should be retained. Since the pros and cons of the proposal posted on the ICTV website are not widely consulted, the arguments are summarized here in order to reach a wider audience.     

Dissections of regional lymph nodes for treatment of skin cancer: predicting annual caseloads that will optimise outcomes

IntroductionDissection of regional lymph nodes (RLNs) can lead to significant morbidity and a high prevalence of complications. Published guidance states that these procedures should be carried out by surgeons who are members of a specialist skin multidisciplinary team who carry out a combined minimum of 15 axillary/groin dissections per year. However, there is little evidence to guide this minimum figure of procedures. We report on the burden of service provision and prevalence of complications across the South West of England and Wales.MethodsA 12-month review of dissections of RLNs for skin cancer was undertaken covering five Plastic Surgery Units with a collective catchment of 8.4 million people. Detailed data were collected on patient demographics, pathology, timing of surgery, and prevalence of complications.ResultsA total of 163 dissections were carried out. Forty-three per cent of patients experienced one or more complication. In that 12-month period, an average of 8 axillary/groin dissections was carried out per surgeon. A funnel plot demonstrated that the prevalence of complications for individual surgeons was within the limit of the plot but, in many cases, this was based only on a relatively small number of procedures per consultant. If surgeons carried out 10 procedures per year, the upper and lower limits on the plot were 73% and 11%, respectively.ConclusionsFunnel plots can provide a useful guide as to whether the prevalence of complications for procedures for individual surgeons lies within acceptable limits. Based on these results, 10 procedures per consultant per year should be sufficient to enable meaningful assessment of the prevalence of complications.     

In Vitro Activity of wALADin Benzimidazoles against Different Life Cycle Stages of Plasmodium Parasites

wALADin1 benzimidazoles are specific inhibitors of δ-aminolevulinic acid dehydratase from Wolbachia endobacteria of filarial nematodes. We report that wALADin1 and two derivatives killed blood stage Plasmodium falciparum in vitro (50% inhibitory concentrations, 39, 7.7, and 12.8 μM, respectively). One of these derivatives inhibited gliding motility of Plasmodium berghei ANKA infectious sporozoites with nanomolar affinity and blocked invasion into hepatocytes but did not affect intrahepatocytic replication. Hence, wALADin1 benzimidazoles are tools to study gliding motility and potential antiplasmodial drug candidates.