High-Resolution Free-Breathing Automated Quantitative Myocardial Perfusion by Cardiovascular Magnetic Resonance for the Detection of Functionally Significant Coronary Artery Disease.

AIMS: Current assessment of myocardial ischaemia from stress perfusion cardiovascular magnetic resonance (SP-CMR) largely relies on visual interpretation. This study investigated the use of high-resolution free-breathing SP-CMR with automated quantitative mapping in the diagnosis of coronary artery disease (CAD). Diagnostic performance was evaluated against invasive coronary angiography (ICA) with fractional flow reserve (FFR) measurement. METHODS & RESULTS: Seven-hundred and three patients were recruited for SP-CMR using the research sequence at 3 Tesla. Of those receiving ICA within 6 months, 80 patients either had FFR measurement, or identification of a chronic total occlusion (CTO) with inducible perfusion defects seen on SP-CMR. Myocardial blood flow (MBF) maps were automatically generated in-line on the scanner following image acquisition at hyperaemic stress and rest, allowing myocardial perfusion reserve (MPR) calculation. 75 coronary vessels assessed by FFR, and 28 vessels with CTO were evaluated at both segmental and coronary territory level. Coronary territory stress MBF and MPR were reduced in FFR-positive (≤ 0.80) regions (median stress MBF: 1.74 [0.90-2.17] ml/min/g; MPR: 1.67 [1.10-1.89]) compared with FFR-negative regions (stress MBF: 2.50 [2.15-2.95] ml/min/g; MPR 2.35 [2.06-2.54] p < 0.001 for both). Stress MBF ≤ 1.94 ml/min/g and MPR ≤ 1.97 accurately detected FFR-positive CAD on a per-vessel basis (area under the curve: 0.85 and 0.96 respectively; p < 0.001 for both). CONCLUSIONS: A novel scanner-integrated high-resolution free-breathing SP-CMR sequence with automated in-line perfusion mapping is presented which accurately detects functionally significant CAD.

Inactivated whole-cell bacterial vaccines: current status and novel strategies.

Inactivated bacterial whole-cell vaccines have been the most widely studied prophylactic treatment for infectious diseases. They offer an economical, and potentially safe, effective means of preventing disease. The disadvantages of these vaccines have been that parenteral administration, while effective in some instances, may have caused adverse reactions in vaccinees, while oral administration often required high doses and resulted in short-term immunity. More recent studies describing new approaches for improving antigenicity of inactivated whole-cell vaccines and the enhancement of immune responses to oral immunization offer great hope for improving the efficacy of these agents. Promising whole cell vaccines include those against Vibrio cholerae, enterotoxigenic Escherichia coli, and more recently Campylobacter jejuni.

Localization of two epitopes recognized by monoclonal antibody PCG-4 on Clostridium difficile toxin A.

The toxin A gene of Clostridium difficile contains a 2.5-kb region encoding a series of contiguous repeating units located at the COOH terminus of the molecule. We previously showed that the monoclonal antibody (MAb) PCG-4, which neutralizes the enterotoxic activity of toxin A, binds to epitopes located within these repeating units. In the present study, we subcloned a series of fragments from this portion of the gene. The recombinant peptides expressed from the gene fragments were examined for reactivity with MAb PCG-4 to identify the epitopes involved in binding. Our results showed that MAb PCG-4 recognizes epitopes in amino acid residues 2097 through 2141 and amino acid residues 2355 through 2398.

Stimulation of Nodulation in the Clover-Rhizobium trifolii 0403 System by Penicillin and Mecillinam.

The number of nodules produced per clover seedling inoculated with Rhizobium trifolii 0403 can be increased almost 2-fold by the addition of penicillin or mecillinam. Two-day-old dutch white clover seedlings grown in 250 milliliter boston round jars containing agar-solidified plant growth medium were inoculated with exponentially growing Rhizobium trifolii 0403 cells. Penicillin or mecillinam (100 micrograms per milliliter) were added immediately or after 24 hours. Following 42 days growth, 10 replicate sets of 5 plants for each treatment were assayed for nodule number, plant dry weight, and Kjeldahl nitrogen. Both antibiotics increased nodule number, plant dry weight, and Kjeldahl nitrogen. Increases in nodule number and dry weight were statistically significant. The range of values in Kjeldahl nitrogen was so extensive as to make the data insignificant at the P < 0.05 level, however nodule number, plant dry weight, and Kjeldahl nitrogen displayed a significant correlation with each other. There were no significant differences in treatment with either antibiotic or with time of treatment. Nodule number increased by about 85%, and plant dry weight and nitrogen increased by about 30%.