Evaluation of diseased coronary arterial branches by polar representations of thallium-201 rotational myocardial imaging

The perfusion territories in polar representations of stress Tl-201 rotational myocardial imaging in patients with angina pectoris who had one diseased coronary segment were analyzed. The lesions proximal or distal to the first major septal perforator in left anterior descending arteries were detected by the presence or absence of defects at the base of the anterior septum. Right coronary artery lesions were detected by the presence of defects at the basal posterior septum, in contrast to the preservation of myocardial uptake at this portion in lesions of the left circumflex artery. The specific defect patterns were detected in cases with lesions at the first diagonal, obtuse marginal, and posterolateral branches. Recognition of these defects in the polar maps allows detailed detection of diseased coronary arterial branches.     

Autoradiographic Analysis of Radiolabeled Anti-carcinoembryonic Antigen Monoclonal Antibody CEA102 in Colorectal Cancer Using Computed Radiography

Anti-carcinoembryonic antigen monoclonal antibody (MAb) CEA102 was produced by immunization with purified CEA and the specific accumulation of radiolabeled CEA102 in colorectal cancers was investigated by autoradiography of surgical specimens using Fuji Computed Radiography (FCR). Five patients with colorectal cancer were injected intravenously with ¹³¹I-labeled intact CEA102 or its F(ab')₂. Primary tumor and liver metastases were successfully detected by external scanning with a gamma camera in 4 cases. Autoradiographic study of the surgical specimens using FCR showed predominant localization of ¹³¹I-labeled CEA102 in primary tumors and liver metastases in all cases. Even a small liver metastasis (0.5 cm) was clearly visualized in the autoradiogram by FCR. The pixel distribution curves of the density of the respective tissues in the autoradiograms by FCR showed the heterogeneity of the distribution of administered radiolabeled MAb in individual tumors, but the density of the tumors was higher than that of the normal tissues. In the quantitative distribution analysis of CEA102, the uptake of the primary tumor (mean 1.10%ID/kg) was ten-fold greater than that of the normal colon mucosa (mean G.10%ID/kg). These results revealed that the application of MAb has great potential in radioimmunodetection as well as in antibody-directed therapy.     

beta-Hydroxybutyrate fuels synaptic function during development. Histological and physiological evidence in rat hippocampal slices.

To determine whether ketone bodies sustain neuronal function as energy substrates, we examined the effects of beta-hydroxybutyrate (betaHB) on synaptic transmission and morphological integrity during glucose deprivation in rat hippocampal slices. After the depression of excitatory postsynaptic potentials (EPSPs) by 60 min of glucose deprivation, administration of 0.5-10 mM D-betaHB restored EPSPs in slices from postnatal day (PND) 15 rats but not in slices from PND 30 or 120 rats. At PND 15, adding D-betaHB to the media allowed robust long-term potentiation of EPSPs triggered by high frequency stimulation, and prevented the EPSP-spike facilitation that suggests hyperexcitability of neurons. Even after PND 15,D-betaHB blocked morphological changes produced by either glucose deprivation or glycolytic inhibition. These results indicate that D-betaHB is not only able to substitute for glucose as an energy substrate but is also able to preserve neuronal integrity and stability, particularly during early development.     

Degradation of protease inhibitors, immunoglobulins, and other serum proteins by Serratia protease and its toxicity to fibroblast in culture

We investigated the effect of the extracellular protease of Serratia marcescens on human serum constituents such as immunoglobulins, fibronectin, alpha 1-protease inhibitor, alpha 2-macroglobulin, lysozyme, and transferrin. At a very low concentration of Serratia 56-kilodalton protease (56K protease), purified human plasma fibronectin was degraded rapidly into three structural domains or small fragments. Immunoglobulin G3 (IgG3) and IgA1 were also degraded within 30 min with 1 microgram of this protease per ml, more rapidly than their other subclass of IgG or IgA. alpha 1-Protease inhibitor, which did not inhibit the 56K protease, was degraded similarly by the protease. These events were demonstrated by fluorescence polarization and sodium dodecyl sulfate-polyacrylamide gel electrophoresis. The protease was considerably inhibited by human alpha 2-macroglobulin and chicken ovomacroglobulin. However, when there was a 2 M excess of ovomacroglobulin or a 4 M excess of alpha 2-macroglobulin over the 56K protease, about 25 or 40% proteolytic activity remained, respectively. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis showed that the protease degraded the alpha 2-macroglobulin extensively during prolonged incubation, which paralleled with regeneration of the protease activity. The protease also cleaved human lysozyme, although moderately. Human serum transferrin was degraded slightly, and human serum albumin was almost resistant to the 56K protease. The enzyme seemed to have no effect on reconstituted collagen, but it degraded rat tropocollagen and yielded fragments of beta and gamma chains by cleaving the intramolecular cross-links. Most of the above proteolysis by the 56K protease appears to result in a limited type of substrate specificity. Thus, the present study demonstrates that the protease is capable of degrading defense-oriented humoral proteins and tissue constituents. Furthermore, it is toxic to fibroblasts. These findings also clarified the possible role of Serratia protease as a virulence factor in the pathogenesis of serratial infections. We recently demonstrated this notion in vivo with rabbit cornea (R. Kamata et al., Ophthalmology 92:1452-1459, 1985).     

Establishment and characterization of αs1-casein–specific T-cell lines from patients allergic to cow’s milk: Unexpected higher frequency of CD8 T-cell lines

To study cow’s milk allergy at the cellular level, we assessed the reactivity of peripheral blood mononuclear cells from patients allergic to cow’s milk to α_s1-casein, which is one of the major allergens in cow’s milk. Proliferation of the cells to α_s1-casein activation showed a rather weak response. Therefore to understand T-cell reactivity to α_s1-casein in more detail, we prepared α_s1-casein–specific T-cell lines from patients allergic to cow’s milk and established 26 T-cell lines. These T-cell lines could be classified into three groups by analyzing their surface marker expression: those containing predominantly CD4⁺CD8^- T cells, those containing both CD4⁺CD8^- and CD4^-CD8⁺ T cells, and those containing predominantly CD4^-CD8⁺ T cells. The CD8⁺ T cells were obtained at an unexpectedly higher frequency from the patients. These T-cell lines produced interferon-γ and IL-4. These results suggest that CD8⁺ T cells specific for α_s1-casein and CD4⁺ T cells were primed by the stimulation with α_s1-casein in patients allergic to milk and that both T cells may play a key role in the onset, progression of, or recovery from cow’s milk allergy. (J ALLERGY CLIN IMMUNOL 1996;97:1342-9.)     

Visual response properties of neurons in the parahippocampal cortex of monkeys

We examined visual response properties of single neurons in the parahippocampal (PH) cortex of alert monkeys using various visual stimuli (bars, geometrical shapes such as a circle, and images such as a human face) while the monkey fixated a spot for a juice reward. Of the investigated PH neurons 104 of 359 (29%) were found to be visually responsive. The investigation was focused on spatial and object aspects of visual processing. We investigated a visual receptive field (RF) property and a direction selectivity for a moving bar with respect to spatial processing. For half of these PH neurons (53%), the optimal stimulus position, where a visual stimulus elicited the maximal response, located peripherally, that is, with an eccentricity of more than 10 deg. More than 20% of these PH neurons had an RF that does not include the center of gaze. There were neurons in the PH cortex that appeared to convey motion signals. In addition, some PH neurons showed eye-position-dependent activity. With respect to object processing, we investigated selectivities for images, geographical shapes, orientations of a bar, and colors. For comparison purposes, we also examined responses of perirhinal (PR) neurons. PH neurons showed selective responses to these stimuli, but PR neurons were found to be more selective for images than PH neurons. These results suggest that the PH cortex is involved in both spatial and object processing, but less involved than the PR cortex in processing of complex images.     

Microtia as an autosomal dominant mutation in a transgenic mouse line: a possible animal model of branchial arch anomalies

Microtia was found in a transgenic mouse 643 and all offspring with microtia had the transgene. No anomalies, other than occasional low set ear and abnormal biting, were identified in other tissues and organs. In the developmental analysis, on the 9th and 10th days of gestation, hypoplasia of the second branchial arch was observed, while various kinds of malformed hillocks were noted on the 12th day. All of these anomalous embryos were transgenic. Histologically, hemorrhage and subsequent phagocytosis were noted at the second branchial arch. Left sided anomalies were predominant and in bilaterally defective ones asymmetry existed. These findings closely resembled to those in experimental animals with a phenocopy of the first and second branchial arch syndrome in humans. Since all other transgenic mouse lines with the same transgene as 643 appeared normal, this dysmorphic phenotype may be caused by an insertional mutation of a host gene, although inappropriate expression of the transgene should be examined further as a possible cause. These results suggest that this transgenic mouse line 643 may be useful as an animal model of branchial arch anomalies in humans.