Blood culture negative infective endocarditis in adult congenital heart disease patients with prosthetic grafts: a case series.

BACKGROUND: Blood culture negative infective endocarditis (BCNIE) is often a diagnostic challenge in adult congenital heart disease patients leading to misdiagnosis, treatment delay and associated high mortality. Studies of BCNIE in adult congenital heart disease patients repaired with prosthetic cardiovascular grafts are limited. CASE SUMMARY: We report two cases of BCNIE where serology testing, multiple polymerase chain reaction testing of explanted valve material and multi-modality imaging including 18F-fluorodeoxyglucose positron emission tomography/computed tomography (18F-FDG PET/CT) were utilized not only to confirm the diagnosis but also to guide management strategy and inform prognosis. Both patients were treated successfully with cardiac surgery and prolonged anti-microbial therapy. DISCUSSION: Clinical presentation of BCNIE in repaired CHD patients is highly variable. The symptoms are often non-specific with subacute or chronic presentation. This may mislead initial diagnosis and subsequent management. Multi-modality imaging including PET/CT should be considered to support the diagnosis, define the extent of infection, decide the management strategy and inform prognosis in patients. A thorough history of animal exposure, and consideration of serology and multiple molecular testing to identify the causative organism, is critical in the management of BCNIE.

Influence of yeast-derived 1,3/1,6 glucopolysaccharide on circulating cytokines and chemokines with respect to upper respiratory tract infections.

OBJECTIVE: Wellmune WGP is a food supplement containing a refined 1,3/1,6 glucopolysaccharide that improves the antimicrobial activity of the innate immune cells by the priming of lectin sites. This study aimed to investigate whether Wellmune decreases the frequency and severity of upper respiratory tract infection (URTI) symptoms over 90 d during the peak URTI season in healthy university students. The secondary aims included an assessment of plasma cytokine and chemokine levels. METHODS: This was a randomized, double-blinded, placebo-controlled trial lasting 90 d. One hundred healthy individuals (18-65 y old, mean age ~21 y) were randomized to 250 mg of Wellmune once daily or to an identical rice flour-based placebo. Health was recorded daily and two or more reported URTI symptoms for 2 consecutive days triggered a medical assessment and blood collection within 24 h. The URTI symptom severity was monitored. Plasma cytokines and chemokines were measured at day 0, day 90, and during the confirmed URTI. RESULTS: Ninety-seven participants completed the trial (Wellmune, n = 48; placebo, n = 49). The Wellmune tended to decrease the total number of days with URTI symptoms (198 d, 4.6%, versus 241 d, 5.5% in the control group, P = 0.06). The ability to "breathe easily" was significantly improved in the Wellmune group; the other severity scores showed no significant difference. Cytokines and chemokines were not different between the groups at study entry or day 90, but monocyte chemotactic protein-1 was lower in the Wellmune group during the URTI. CONCLUSION: Wellmune may decrease the duration and severity of URTI. Larger studies are needed to demonstrate this.

Determination of paralytic shellfish toxins in dinoflagellate Alexandrium tamarense by using isotachophoresis/capillary electrophoresis.

Baseline separation of seven paralytic shellfish toxins (PSTs), namely decarbamoylsaxitoxin (dcSTX), saxitoxin (STX), neosaxitoxin (NEO), gonyautoxin-2 (GTX-2), gonyautoxin-3 (GTX-3), gonyautoxin-1 (GTX-1), and gonyautoxin-4 (GTX-4), was achieved by using capillary ITP (CITP)/CE with UV detection. Separation parameters including duration time and voltage in CITP process, separation voltage, and pH and concentration of buffer were optimized. The developed method provided linear responses from 1.3 to 200 microM for the PSTs. The LOD ranged from 0.1 to 0.3 microM. PST extracts from two algal strains of Alexandrium tamarense were analyzed and the toxin concentrations in the samples were quantified with an internal standard method by using NEO as the internal standard. The algal extract of A. tamarense HK9301 contained 332 microM GTX-2 and 224 microM GTX-3, while the PSTs were not detected in the extract of A. tamarense CI01.

Identification and characterization of a "biomarker of toxicity" from the proteome of the paralytic shellfish toxin-producing dinoflagellate Alexandrium tamarense (Dinophyceae).

The objective of this study was to identify and characterize a "biomarker of toxicity" from the proteome of Alexandrium tamarense, a paralytic shellfish toxin (PST)-producing dinoflagellate. A combination of 2-DE and MS approaches was employed to identify proteins of interest in the vegetative cells of several strains of A. tamarense with different toxin compositions and from different geographical locations. The electrophoretic analysis of the total water-soluble proteins from these toxic strains by 2-DE showed that several abundant proteins, namely AT-T1, AT-T2 and AT-T3, differing slightly in apparent Mr and pIs, were consistently present in all toxic strains of A. tamarense. Further analysis by MALDI-TOF MS and N-terminal amino acid sequencing revealed that they are isoforms of the same protein. Even more intriguing is that these proteins in A. tamarense have similar amino acid sequences and are closely related to a "biomarker of toxicity" previously reported in A. minutum. Unambiguous and highly species-specific identification was later achieved by comparing the PMFs of proteins in these two species. An initial attempt to characterize these proteins by generation of murine polyclonal antibodies against the AT-T1 protein was successful. Western blot analysis using the murine AT-T1-polycolonal antibodies identified all the toxic strains of A. tamarense and A. minutum, but not the nontoxic strain of A. tamarense. These results indicate that these protein characteristics for toxic strains are species-specific and that they are stable properties of the tested algae which are clearly distinguishable irrespective of geographical location and toxin composition. To our knowledge, this is the first study to demonstrate the use of polyclonal antibodies against marker proteins purified from 2-DE gels to distinguish different strains and species of the PST-producing dinoflagellate Alexandrium. It provides the basis for the production of monoclonal antibody probes against the "biomarkers of toxicity" for those dinoflagellates whose genome is incompletely characterized. Potentially, immunoassays could be developed to detect the presence of toxic algae in routine monitoring programs as well as to predict bloom development and movement.