Diffusion Weighting by the Trace of the Diffusion Tensor within a Single Scan

The anisotropy of the water diffusion tensor inside brain causes contrast in diffusion images, which depends on the relative orientation of the diffusion gradients and the subject. Because the trace of a tensor is invariant upon rotation, measurement of this trace can reduce the orientation effect. A family of imaging pulse sequences is presented in which the signal intensity is weighted by the trace of the diffusion tensor in a single scan. The methods are demonstrated for chicken gizzard in several orientations with respect to the gradient frame of reference, and for ischemic injury in cat brain after middle cerebral artery occlusion. The sensitivity of the techniques to the presence of background gradients is measured and discussed in detail. As a result, pulse sequences are suggested that provide reliable diffusion constants in both homogeneous and inhomogeneous magnetic fields. The efficiency of the techniques for clinical application is also evaluated.     

Effects of calcium in continuous cardioplegia on myocardial protection

The effects of calcium (Ca) on a hyperkalemic cardioplegic solution for continuous cardioplegia were examined in an isolated perfused working rat heart model. The coronary arteries were perfused with a modified Krebs-Henseleit bicarbonate buffer (K-H) solution, containing various concentrations of Ca(0.1, 0.6, 1.2, and 2.5 mmol/l) and a high concentration of potassium (20 mmol/l), for 180 min, after which cardiac arrest was induced at 37°C for 180 min. Cardiac function and creatine kinase (CK) were measured. In the control group, K-H solution was infused in place of the cardioplegic solution, and cardiac arrest was not induced. No significant differences were observed between the groups infused with the K-H solution containing Ca concentrations of 0.6, 1.2, and 2.5 mmol/l in the percent recovery of aortic flow (82.1±2.9%, 80.6±2.0%, and 71.5±3.7% (mean±SEM) respectively) or in the recovery of other indices of cardiac function, or in CK leakage. There were also no significant differences in the recovery of cardiac function and CK leakage between these groups and the control group. In the Ca 0.1 mmol/l group, however, the characteristic Ca paradox was observed. These findings suggest that if the Ca concentration in a cardioplegic solution is higher than 0.6 mmol/l during continuous cardioplegia, excellent cardioprotective effects will be achieved.     

Development of new immunoradiometric assay for CA 125 antigen using two monoclonal antibodies produced by immunizing lung cancer cells

CA 125 is an antigen associated with non-mucinous epithelial ovarian cancer, which is defined by OC 125 antibody developed by immunizing ovarian cancer cells. We have produced two monoclonal antibodies, 130-22 and 145-9, by using the human lung adenocarcinoma cell line PC-9. Both 130-22 and 145-9 antibodies recognized CA 125 antigen. However, the binding sites seemed to be separate from those of OC 125. Testing by 9 immunoradiometric assays (IRMA), using different combinations of the 3 monoclonal antibodies 130-22, 145-9 and OC 125 demonstrated that the best standard curve for detecting CA 125 could be obtained by a "simultaneous sandwich" assay based on a mixture of 125I-labeled OC 125 and 130-22 or 145-9 coated beads. One-step IRMA, using 130-22 as a tracer and 145-9 as an immunoadsorbent, also showed good reproducibility and sensitivity for measuring CA 125. Antigens were detectable in the culture supernatants of PC-9 cells and 5 of 6 ovarian cancer and endometrial adenocarcinoma cells. These results indicate that one-step IRMA using 130-22 and 145-9 is useful for detecting CA 125 antigen.     

Inhibition of polymorphonuclear leukocyte adherence suppresses no-reflow after focal cerebral ischemia in baboons.

BACKGROUND AND PURPOSE: While polymorphonuclear leukocytes may contribute to the "no-reflow" phenomenon after focal cardiac and skeletal muscle ischemia/reperfusion, their contribution to acute focal cerebral ischemia is unresolved. We have examined the role of polymorphonuclear leukocytes in microvascular perfusion defects after focal cerebral ischemia/reperfusion in a baboon model of reversible middle cerebral artery occlusion with the anti-CD18 monoclonal antibody IB4, which inhibits neutrophil adherence to endothelium. METHODS: Microvascular patency in the basal ganglia after 3-hour middle cerebral artery occlusion and 1-hour reperfusion (by india ink tracer perfusion) was quantified by computerized video imaging. Animals were randomized to receive intravenous IB4 infusion 15 minutes before reperfusion (n = 7) or to receive no treatment (n = 6). Binding of IB4 to baboon leukocytes was maximal within 5 minutes of infusion. RESULTS: In the untreated group, a significant reduction in patency was observed in microvessels less than 30 microns diameter: mean percent reflow was 51% in the capillary diameter class (4.0-7.5 microns) and 39% in the precapillary arteriole and postcapillary venule diameter class (7.5-30 microns). Infusion of IB4 before middle cerebral artery reperfusion increased reflow in microvessels of all size classes, most significantly in those 7.5-30 microns (p = 0.049) and 30-50 microns (p = 0.034) in diameter. CONCLUSIONS: These results suggest that CD18-mediated polymorphonuclear leukocyte-endothelium adherence contributes to no-reflow predominantly in noncapillary microvessels and at least partially to that in capillaries.     

Intrahepatic Delivery of Glutathione by Conjugation to Dextran

Glutathione was covalently attached to dextran (T-40) by the CNBr activation method. The compound obtained was a water-soluble powder containing 10 (w/w%) glutathione, which was gradually released from the conjugate in aqueous media. Mice depleted of glutathione by treatment with buthionine sulfoximine, a potent inhibitor of -glutamylcysteine synthetase, exhibited a significant increase in hepatic glutathione level after intravenous injection of the conjugate. In mice given a lethal dose of acetaminophen, the survival rate increased progressively with coadministration of the conjugate, whereas little improvement was found when free glutathione was given. The conjugate maintained the serum transaminase activities at lower level after acetaminophen administration. These findings suggest that the dextran conjugate of glutathione is transported into hepatic cells and is intracellulary hydrolyzed to free form, which protects mice from hepatotoxicity due to acetaminophen.     

DNA aneuploidy assessment of the effectiveness of hyperthermo-chemo-radiotherapy for esophageal carcinoma

The relationship between DNA ploidy and effects of preoperative hyperthermo-chemo-radiotherapy were investigated in 118 patients who underwent esophageal resection and reconstruction for carcinoma of the esophagus, including 56 treated with hyperthermo-chemo-radiotherapy (HCR therapy) and 62 treated with chemo-radiotherapy (CR therapy). DNA ploidy patterns were grouped into low and high ploidies, according to the degree of dispersion and the peak value on the DNA histogram. In the low ploidy group, there were no significant differences in the prognosis and histologic effects between the HCR and CR therapies. In the high ploidy group, however, the difference in survival curves was statistically significant, the 3-year survival rates of patients given HCR therapy and CR therapy being 26.7% and 10.7%, respectively (P less than 0.05). The HCR therapy increased the rate of "markedly effective" in the resected tissue compared with findings in cases of CR therapy. These findings show the positive effects of the HCR therapy for carcinoma of the esophagus, especially for patients with an aneuploid profile and a poor prognosis.     

GAMMA HEAVY CHAIN DISEASE

Electron microscopic and immunohistochemical studies were carried out on materials obtained from three patients of gamma heavy chain disease ( λ -HCD). Electron microscopically, proliferating cells showed various stages of maturation from immunoblast to plasma cell, and the majority of proliferating cells were proplasmacytes and plasma cells. From the intracytoplasmic immunoglobulin studies by immunoperoxidase method (PAP method) and electron microscopical enzyme-labeled antibody technique, proliferating cells, such as the immunoblast, plasmablast, proplasmacyte, and plasma cell, showed positive reaction to anti- λ -heavy chain serum and anti-Fc fragment (IgG) serum, and also in a third case with Bence Jones protein, proliferating cells showed positive reaction to anti_-K light chain serum. We would conclude that proliferating cells in λ -HCD might be a single clone proliferation of B-cell synthesizing λ -HCD protein, and the predominant proliferation cells are proplasmacytes and plasma cells situated near mature plasma cells in the B-cell line.     

Ionic stimulation of the olfactory epithelium in the bullfrog and the carp.

The stimulating effects of mono- and divalent cations and anions were studied in the olfactory epithelia of the bullfrog and the carp. The rhythmic waves induced by these ions were recorded in the olfactory bulb. 1. Many mono- and divalent cations and anions showed stimulating actions in the bullfrog and the carp. 2. Microelectrode studies disclosed that the olfactory receptor cells respond to different ions differently. 3. When many ions were applied with various concentrations, responses appeared with long latencies while the concentration was very low (the "delayed responses"). The responses nearly disappeared at the intermediate concentrations, but then responses with short latencies appeared at the higher concentrations (the "initial responses"). Thus, many ions showed dual responses in the bullfrog, although some exceptional cases were found (choline+, Tl+, La3+, Cd2+). 4. Cd2+ and other heavy metal ions showed depressive actions upon the responses induced by other ions in the olfactory epithelium. 5. Tetrodotoxin of even 10 (-5) g/ml was found ineffective in depressing the rhythmic waves induced by ions. 6. Chemoreceptive activities of the olfactory epithelia of the bullfrog and the carp were compared with the activities of the gustatory receptors. They were also compared with the other chemoreceptors of the fish, namely the palatal organ, external chemoreceptors over the snout region and the lateral-line organ. Chemical senses of the fish were discussed.