The sequential differentiation patterns of thymocyte were observed with cell surface phenotypes and the expression of T cell antigen receptor in 800 rad irradiated adult mice. Thymus was severely reduced in size and cell number by day 5 after whole body irradiation and rapidly recovered from day 7 to day 14. Surface marker analysis on day 5 after irradiation showed thymocytes with Thy-1low L3T4+/Lyt-2- dominantly existed and suggested that these cells were radioresistant-survived cells. On the other hand, thymocytes on day 7 were composed of a large number of Thy-1high L3T4+/Lyt-2+ blast-like cells and a relatively high proportion of Thy-1high L3T4-/Lyt-2- cells which expressed a large amount of gamma-chain gene messages but scarcely any alpha- and beta-chain gene messages similar to the fetal thymocytes. On day 14, thymocytes were composed mostly of Thy-1high H-2low L3T4+/Lyt-2+ subpopulation which expressed a remarkably low level of gamma-chain gene messages, and high levels of alpha- and beta-chain transcripts analogous to those of normal adult thymus. Taken together, intrathymic radioresistent stem cells for T thymocytes seem to proliferate and differentiate after irradiation with the same pattern as was seen in a fetal thymus development.

Animals↗

PubMed1987

The acceleration of Na+,K+-ATPase activity by ATP and ATP analogues.

Since Na+,K+-ATPase (EC 3.6.1.3) of pig kidney modified with a fluorescent sulfhydryl reagent, N-[p-(2-benzimidazolyl) phenyl]maleimide, at Cys-964 of the alpha-chain showed ATP-dependent, reversible, and dynamic fluorescence changes (Nagai, M., Taniguchi, K., Kangawa, K., Matsuo, S., Nakamura, S., and Iida, S. (1986) J. Biol. Chem. 261, 13197-13202), we studied the conformational change during Na+,K+-ATPase reaction using the modified enzyme. The addition of K+ to the enzyme increased the fluorescence intensity to 2% in the presence of 160 mM Na+ and 3 mM Mg2+ (K0.5 = 16.4 mM). Addition of low concentrations of ATP immediately increased the intensity to 3.2% (K0.5 less than 0.1 microM) to accumulate fully K+-bound enzyme in the presence of 43 mM K+ with Na+ and Mg2+, but further addition of higher concentrations of ATP diminished the increase (K0.5 = 120 microM). After exhaustion of ATP, the fluorescence intensity decreased to -0.4% (K0.5 = 0.3 microM) and -2% (K0.5 = 20 microM), respectively, in the presence of low and high concentrations of ADP produced from ATP. High concentrations of ATP accelerated Na+,K+-ATPase activity with a simultaneous increase in the amount of ADP-sensitive phosphoenzyme irrespective of the modification. Adenylyl imidodiphosphate and ADP accelerated Na+,K+-ATPase activity in the presence of 2.7 microM ATP by decreasing the extent of the fluorescence without affecting the amount of phosphoenzyme, irrespective of the modification. These data suggest that Na+,K+-ATPase activity was accelerated due to the acceleration of the breakdown of K+-bound enzyme by high concentrations of ATP and ATP analogues.

Adenosine Diphosphate↗

PubMed1987

Atomic excitation as the result of inner-shell vacancy production.

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Journal Article↗

PubMed1987

T-cell recruitment from the thymus to the spleen in tumor bearing mice: phenotypical alteration and recruitment of thymocytes raised in a tumor bearing state.

Intrathymic events in mice bearing methylcholanthrene induced fibrosarcoma (MBS-1) were examined using mainly flow cytometric analysis. Ten days after tumor inoculation, the number of whole thymocytes was remarkably decreased. Surface phenotypical analysis by flow cytometry showed that the proportion of thymocytes with a low density of peanut agglutinin (PNAlow thymocytes), which is about 30% in normal mice, was increased to 70%. Histologically, the greater part of the thymus was occupied by the cortex. Moreover, the ratio of proliferating cells was increased in the PNAhigh cells. These findings in in vivo experiments suggested that a tumor bearing state would alter phenotypical characteristics of cortical thymocytes (PNAhigh, Thy 1high, H-2low) to medullary type (PNAlow, Thy 1low, H-2high). To support this hypothesis, in vitro experiments were performed using cultured thymic lymphoma EL4 cells, which possessed an immature thymus cell phenotype. Addition of serum from MBS-1 bearers to the culture medium of EL4 cells differentiated their phenotypical characteristics to the medullary type. Thus, it is assumed that factors in tumor bearers induce a massive migration of thymocytes by altering of phenotypes.

Animals↗

PubMed1987

Different virus-precipitating activities of neutralizing monoclonal antibodies that recognize distinct sites of poliovirus particles.

Two neutralizing monoclonal antibodies (4 C 4 and 4 F 2) against type 1 poliovirus, Mahoney strain, recognized distinct antigenic sites of the virus particles; 4 C 4 antibody bound to vertices of native and heated (56 degrees C, 30 minutes) virus of Mahoney strain, while 4 F 2 antibody reacted with specific surface protrusions of native virus of Mahoney and Sabin strains. The difference in the location of neutralization epitopes with which the two antibodies react was confirmed in the neutralization reaction by the use of mutants resistant to 4 C 4 and 4 F 2 antibody. In immune electron microscopy, double immunodiffusion and sucrose density gradient analysis of virus-antibody complexes, the two antibodies showed a marked difference in their virus-precipitating activities. The 4 C 4 antibody recognizing vertices of the virus particle had little virus-precipitating activity. In contrast, the 4 F 2 antibody that bound to specific surface protrusions of native virus aggregated virus particle efficiently. In neutralization assays, however, the 4 C 4 antibody exhibited a slightly stronger neutralizing activity than the 4 F 2 antibody. Thus, it was suggested that the strength in precipitating activities of the two antibodies did not correlate with that in their neutralizing activities.

Antibodies, Monoclonal↗

PubMed1987

Inverse relationship in H-2-associated lysis between NK cells and rIL-2-activated killer cells: evidence from in vitro killing and metastatic experiments.

We investigated the manner in which rIL-2 induced effectors in vitro (LAK cells), which, like NK cells, lyse targets nonspecifically and discriminate nonself, and how H-2 as the self-marker affects the LAK cell killing mechanism. NK cells showed an appreciably higher killing activity to B16 melanoma H-2- cells than to H-2+ cells. In contrast, LAK cells lysed more efficiently to H-2+ cells. The in vivo experiments showed that the NK cells prevented pulmonary metastasis of B16 H-2- cells in the normal syngeneic host, whereas the transferred LAK cells had a preferential inhibitory effect on the pulmonary metastasis of B16 H-2+ cells in the immunodeficient syngeneic hosts. Taken together, these results show that the H-2-encoded or H-2-associated molecules contribute to the triggering signal in the lysis by LAK cells, whereas the NK cells recognize the reduced self H-2 expression on the targets, thereby contributing to a trigger of the lysis.

Animals↗

PubMed1987

Positive effects of indomethacin on restoration of splenic nucleated cell populations in mice given sublethal irradiation.

Splenic cellularity during the recovery phase after 400-R irradiation was evaluated in mice, in which the level of prostaglandin was regulated by indomethacin and exogenous prostaglandin E2, following sublethal irradiation. Two weeks after irradiation, administration to these mice of indomethacin, an inhibitor of prostaglandin synthesis, augmented the recovery of all nucleated spleen cell populations, whereas the thymus was drastically depopulated. This treatment had little effect upon the total number of bone marrow cells but inversed the ratio of PNA+/PNA- cells. Cell transfer experiments using heavily irradiated mice as recipients showed that the stem cell proliferation was positively affected by indomethacin treatment in the bone marrow rather than in the spleen. These results suggest that cell migration from primary lymphoid organs, particularly from the bone marrow to the spleen, is regulated by a prostaglandin-mediated system and that a prostaglandin E2 synthesis inhibition would have a positive effect on the restoration of peripheral nucleated cells following irradiation.

Animals↗

PubMed1987

Effects of excess methionine on collagen metabolism: a study on newborn rat skin.

We studied the biochemical effects of excess methionine intake on the skin of newborn rats. Group 1 pups were intubated with methionine dissolved in 0.1 ml physiological saline solution in the amount of 0.1 g/100 body wt as a control using a gastric needle. Group 2 pups were given 0.2 g/100 g in the same manner as group 1 as an experimental group. They were intubated every other day from day 3 to 13. On Day 15, [14C]proline was injected intraperitoneally into pups and their skin was removed. 14C total and hydroxyproline uptake was examined in the tissue as well as in the sequential extracts. Although excess methionine intake by the pups did not alter the collagen content of their skin, it caused an increase in the content of type III collagen and a decrease in crosslinked collagen. In addition, newly synthesized collagen in the neutral salt extract increased in the excess methionine group, indicating that crosslinked collagen decreases as excess methionine was intubated. The present study demonstrated that excess methionine in the early lactational period altered the nature of the skin collagen of suckling newborn rat pups.

Animals↗

PubMed1987

Additional aortopulmonary anastomosis for subaortic obstruction in the Rastelli-type repair for the Taussig-Bing malformation.

In the Taussig-Bing malformation, residual subaortic obstruction from a hypertrophied subaortic conus is often a problem at the time of intraventricular repair. To alleviate this problem, during a Rastelli-type repair involving an extracardiac valved conduit and an intraventricular connection from the ventricular septal defect to both aortic and pulmonary outflows, an additional side-to-side anastomosis between the ascending aorta and the proximal portion of the divided pulmonary artery can be performed, creating a supplementary outflow for the left ventricle. This method was used in 2 patients who had anteroposterior transposition of the great arteries, with 1 long-term survivor.

Aorta↗

PubMed1987

Radical transurethral resection of the prostate in male paraplegics revisited: further clinical experience and urodynamic considerations for its effectiveness.

We report our experience with radical transurethral resection of the prostate performed on 89 male spinal cord injury subjects. The over-all success rate of modified sphincterotomy was 90 per cent, although there was a 14 per cent recurrence rate with time. Urodynamically, success was characterized by a statistically significant reduction in the degree of detrusor-sphincter dyssynergia, an increase in vesical compliance and a reduction in detrusor hyperreflexia. These results suggest an effect on the distal sphincteric area by the adrenergic system in the genesis of detrusor-sphincter dyssynergia. It is suggested that radical transurethral resection of the prostate exerts this effect via a surgical sympathectomy, while continence is preserved by the activity of the untouched external urethral sphincter.

Adult↗

PubMed1987

Preoperative left ventricular function: minimal requirement for successful late results of valve replacement for aortic regurgitation.

Postoperative survival and left ventricular function were studied in 62 patients who underwent aortic valve replacement for isolated, chronic aortic regurgitation between 1978 and 1985. The average follow-up period was 3.8 years. There were three in-hospital and six late deaths. Five (56%) of the nine postoperative deaths were of cardiac-related causes. The mean 7 year survival rate was 83 +/- 5%. Preoperative left ventricular end-systolic volume index was the most important indicator (p less than 0.001) for subsequent cardiac death. The 6.5 year survival rate was 92 +/- 4% for patients with an end-systolic volume index less than 200 ml/m2 compared with 51 +/- 16% for those whose index was greater than 200 ml/m2. None of the 48 patients with an end-systolic volume index less than 200 ml/m2 died of cardiac-related causes. Twenty-three of the 48 patients with an end-systolic volume index less than 200 ml/m2 (Group 1) and 6 of the 12 patients with a higher index (Group 2) underwent repeat catheterization 26 months postoperatively. Preoperative afterload, assessed by end-systolic wall stress, was elevated in both groups, but decreased postoperatively, becoming identical to the afterload in 20 normal control subjects. Although the preoperative ejection fraction was depressed in both groups, the great majority of patients in Group 1, compared with none in Group 2, exhibited normal ejection fraction postoperatively. Thus, in patients who recently underwent surgery for aortic regurgitation, satisfactory late results in both long-term survival and reversal of left ventricular dysfunction were obtained when the preoperative end-systolic volume index was less than 200 ml/m2.

Adolescent↗

PubMed1987

Interferon gamma induces lung colonization by intravenously inoculated B16 melanoma cells in parallel with enhanced expression of class I major histocompatibility complex antigens.

Treatment of H-2-deficient nonmetastatic B16 melanoma cells with physiological doses of interferon gamma (IFN-gamma) reduced cellular growth in vitro but induced a shift to the lung-colonizing phenotype as assessed after intravenous injection of the treated cells. As little as 1 antiviral unit of recombinant IFN-gamma per ml induced B16 cells to form 3-40 pulmonary metastases in each injected mouse, whereas a 1000-fold higher concentration of IFN-beta was required to see similar effects. IFN-gamma may induce cell-surface molecules that contribute to the metastatic ability of the tumor cells. The efficient enhancement of metastatic ability after IFN-gamma treatment of the B16 cells was paralleled by an increased H-2 antigen expression and decreased sensitivity to natural killer cells. The experiments support the idea that metastasis may not depend exclusively on stable genetic changes or heterogeneity within a tumor population but may be also influenced through the modulation of the phenotype by physiological or pharmacological agents. The results are also discussed with regard to the role of different effector cells in tumor cell clearance and in relation to lymphokine-based strategies for therapy.

Animals↗

PubMed1987

Direct serotyping of human rotavirus in stools by an enzyme-linked immunosorbent assay using serotype 1-, 2-, 3-, and 4-specific monoclonal antibodies to VP7.

Four serotypes of human rotaviruses that can be differentiated by neutralization tests have been described so far. We prepared serotype 1-, 2-, 3-, and 4-specific, neutralizing monoclonal antibodies to human rotaviruses. All were directed to VP7, a glycoprotein that carries a major serotype specificity. An enzyme-linked immunosorbent assay using these monoclonal antibodies has been developed for serotyping human rotavirus isolates. The sensitivity and specificity of this method were verified by using various strains of human rotavirus that were adapted to cell culture. Furthermore, it was shown that the method was applicable to serotyping human rotaviruses directly in stool specimens.

Antibodies, Monoclonal↗

PubMed1987

Cross section of 27Al(n,2n)26Alg.s. near 14 MeV.

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Journal Article↗