CT manifestations of a ruptured hepatic tumor after transcatheter arterial embolization

There are few reports of the radiologic diagnosis of ruptured hepatic tumors. In a patient with right upper abdominal pain and impending shock, angiography demonstrated a hypervascular hepatic tumor, and CT imaged an extrahepatic mass suggestive of a hematoma. Following transcatheter arterial embolization with Lipiodol Ultrafluide and gelatin-sponge, multiple contiguous CT sections revealed numerous lipiodol droplets adjacent to a lipiodol-containing hepatic tumor, clearly outside the liver. These findings were indicative of a ruptured hepatic tumor. After embolization, the patient's condition improved and he was discharged.

Bilio-enteric anastomosis as a risk factor for postembolic hepatic abscesses

In 2 patients who had undergone pancreatoduodenectomy with choledochojejunostomy, a subsequently detected metastatic tumor of the liver was treated with transcatheter arterial embolization. Weeks later intrahepatic abscesses developed. Pathophysiologic processes that may lead to this complication of hepatic embolization are discussed.

Generation of self-macrophage-toxic non-T cells in the MHC-homozygous F1 spleen cells co-cultured with parental cells: possible involvements of host cells in impaired immunity in GVH disease

Simplified-in vitro system was developed to examine the contribution of host's cells in graft-versus-host (GVH)-disease-associated immunodeficiencies. In analogy with major histocompatibility complex (MHC)-matched GVH-reaction, (BALB/c x DBA/2)F1 (H-2d) hybrid spleen cells were co-cultured with irradiated BALB/c (H-2d) spleen cells, so that cellular activities to be generated are ascribable to F1 cells. In vitro development of anti-allo-specific cytotoxic T cells of the F1 origin was dramatically suppressed by coexistence of the irradiated parental cells and by the addition of F1 cells precultured once with the parental cells, suggesting the generation of suppressor cells in the F1 (host) cells activated by the parental cells. Thus generated suppressor cells are Thy.1-, weakly or nonadherent and radiosensitive. Interestingly, in the same reactions there also developed Thy.1- cytotoxic cells for autologous macrophage targets. An involvement in immunodeficiencies in GVH disease of the host-derived cytotoxic and/or immunosuppressive, non-T cells was discussed.

Strain differences of age-dependent changes in the responsiveness to a T-independent type-2 antigen in mice

We have assessed age-associated early changes in antibody response to a T-independent type-2 (TI-2) antigen, dinitrophenylated ficoll (DNP-Ficoll). Mice of most strains, including long-lived and autoimmune-prone strains, give a high response when approximately 2 months old; thereafter the response declines sharply to the 3rd-4th month of age and continues to do so, more gradually, up to the age of 6 months. Age-related changes in the response of C57BL/6 mice follows a different course: the response remains unchanged up to the first year of life, i.e. to middle age. The in vitro anti-DNP-Ficoll antibody response of B cells could be increased by the addition of young syngeneic T cells. The augmenting activity of splenic T cells of C3H/He mice declines clearly as a function of age. In contrast, splenic T cells of C57BL/6 mice have low augmenting activity whether the T cells are obtained from young or middle-aged donors. Unlike the augmenting capacity of T cells, B-cell responsiveness to DNP-Ficoll increases until middle age in all strains examined. We conclude that early age-associated changes in antibody response to the TI-2 antigen is polymorphic and that the early age-related decline in in vivo responsiveness is attributable to an age-associated decline in augmenting T helper cell activity.

Unidirectional responses to Mls determinants in vivo. Polyclonal T-cell responses to a single common determinant of Mls in different efficiencies?

Polyclonal anti-Mls responses of peripheral (mature) and thymic (immature) lymphocytes were studied in vivo in terms of local host-versus-graft and graft-versus-host reactions. The level of stimulatory activity differed between the various types of Mls antigens, with Mlsa and Mlsd having the highest levels. Mlsc a lower level, and Mlsb the lowest level. The immunogenicity of Mlsa and Mlsd may not be identical, since Mlsd mice responded to the Mlsa determinant, while Mlsa mice did not react with the Mlsd determinants. This suggests that the anti-Mls response is unidirectional. The fact that Mlsb mice made tolerant at birth to Mlsd (Mlsa) antigens behave like Mlsd (Mlsa) mice when responding to Mls antigens supports this suggestion. Furthermore, thymus cells from the Mlsa-tolerized BALB/c (Mlsb) mice were unresponsive to both Mlsa and Mlsd antigens, while those made tolerant to Mlsd were responsive to Mlsa. These results indicate that the polyclonal response to the strongly immunogenic Mlsa,d antigens is unidirectional, and that the immunogenicity of Mlsa and Mlsd is not identical. Based on the results of tolerance experiments and data on T-cell clones, we suggest that the difference in immunogenicity between Mlsa,b,d antigens is due to different efficiencies of the responding T-cell populations, probably because of a quantitative difference in a single common antigenic determinant expressed in each Mls haplotype, which results in different levels of stimulation of T cells according to the avidity for the determinant.

T-1583 and forskolin are similar in their cardiac effects and dissimilar in their vascular effects

The cardiac and coronary vascular effects of T-1583, a selective beta 1-adrenoceptor full agonist, and forskolin, a direct activator of adenylate cyclase, were compared in isolated, blood-perfused papillary muscle, sinoatrial node, and atrioventricular (AV) node preparations of dogs. Both agents were injected intra-arterially. The two agents increased the force of contraction of the paced papillary muscle and the unpaced one, and the rate of automaticity of the latter. They increased sinus rate and accelerated AV nodal conduction. In producing these effects T-1583 was 50 to 80 times more potent than forskolin, indicating that both agents have similar cardiac profiles. At the doses that produced a 50% increase in the force of contraction of the papillary muscle, both agents produced about a 20% increase in sinus rate. Such degrees of force-rate separation were close to those obtained with most new positive inotropic agents with an inhibitory action on cyclic AMP phosphodiesterase. T-1583 differed distinctly from forskolin in that the former increased only slightly coronary blood flow, whereas the latter increased it greatly. Thus, forskolin is more coronary vasodilatory than positively inotropic, and more positively inotropic than positively chronotropic. T-1583 is a more positively inotropic than positively chronotropic and more positively chronotropic than coronary vasodilatory.

Improvement of pentobarbital-induced heart failure by MCI-154, a novel and potent cardiotonic agent, in the dog heart-lung preparation

The efficacy of MCI-154, a new pyridazinone cardiotonic agent, in improving heart failure was assessed in dog heart-lung preparations in which cardiac function had been severely depressed by pentobarbital. MCI-154 in doses of 10-100 micrograms improved the cardiac function curve and restored it to the control level at 100 micrograms. At this dose, MCI-154 neither produced an increase in heart rate beyond the control value nor induced arrhythmias. The effects of MCI-154 were not affected by atenolol, a cardioselective beta 1-blocker. These results indicate that MCI-154 would be of potential use in the treatment of heart failure.

Cardiac and coronary vasodilator effects of the novel cardiotonic agent, MCI-154, assessed in isolated, blood-perfused dog heart preparations

MCI-154 is a potent nonglycoside and non-sympathomimetic cardiotonic agent with a pyridazinone structure. We assessed its cardiac and coronary vasodilator effects by use of isolated, blood-perfused papillary muscle, sinoatrial (SA) node, and atrioventricular (AV) node preparations of dogs. The drug (1-100 nmol) was injected intraarterially. MCI-154 increased the force of contraction of paced and unpaced papillary muscles but failed to affect the rate of automaticity of the latter. It increased sinus rate and shortened AV conduction time by accelerating AV nodal conduction, but in all doses examined it produced no arrhythmias. In all preparations, it increased blood flow. All the effects were long-lasting (1-2 h). MCI-154, however, was not homogeneously effective on these cardiovascular variables. The drug was nearly equieffective in producing a positive inotropic effect and coronary vasodilatation, but less effective in producing positive chronotropic and dromotropic effects. In having such a cardiovascular profile, MCI-154 most resembles milrinone among new cardiotonic agents, although unlike milrinone, its main mechanism of cardiotonic action is believed to be the sensitization of the contractile proteins to Ca2+. Whatever mechanisms are involved, the revealed cardiovascular profile of MCI-154 justifies its clinical trial in the treatment of heart failure.

Immune responses in newly developed short-lived SAM mice. Selectively impaired T-helper cell activity in in vitro antibody response

New short-lived strains of mice (SAM-P), which have been developed by Takeda et al. (1981), shows a defective antibody response to T dependent (TD) antigen in vitro, as demonstrated in the accompanying paper (see page 419). In the present study, we investigated the cellular site of the defect, using a cell culture system. In this paper, it is demonstrated that T-helper (Th) cell activity for the antibody response to TD antigen is impaired, while other cellular immune responses, e.g. mixed leucocyte reaction, cytotoxic T-lymphocyte response, and delayed-type hypersensitivity reaction, are normal. These results suggest that the defect in T-helper subset is limited in helper function for the antibody response, and that the helper function for the cell-mediated immune responses is intact. These two functions of the T-helper subset are apparently regulated in a different manner. The SAM-P strains of mice may thus serve as an appropriate model for studying functional heterogeneity in T-helper/inducer cell subsets.

Immune responses in newly developed short-lived SAM mice. I. Age-associated early decline in immune activities of cultured spleen cells

Using a cell culture system, age-associated changes in immune activities were investigated in newly developed, short-lived mouse strains. These SAM-P strains of mice (H-2k), which have a remarkably short life span (around 9 months) under conventional breeding conditions, showed an age-associated early decline in several immune functions, as compared to ordinary strains of AKR/J (H-2k) and C3H/He (H-2k) mice. Their antibody-forming capacity to T-independent antigen, DNP-Ficoll, and natural killer (NK) cell activity showed a markedly early onset of regression and a sharp decline from the level of control mice at 2 months of age. SAM-P strains of mice have a profound defect in antibody response to a T-dependent (TD) antigen, such as sheep red blood cells (SRBC), thus there was only a feeble antibody response to SRBC as early as the age of 2 months, and a negligible response at a later age. In contrast, the allo-specific cytotoxic T lymphocyte (CTL) response of the mice was as high as that of control mouse strains at 2 months of age and declined little until at least 6 months of age. The early age-related functional decline in the immune system of SAM-P mice suggests that these new inbred strains are appropriate models for investigating the age-related appearance of immune dysfunctions.

Effect of DHP-218, a novel dihydropyridine phosphonate, on atrioventricular nodal conductivity compared with its vascular effect in dogs

The effect of DHP-218, a dihydropyridine phosphonate Ca2+ channel blocker, on atrioventricular (AV) nodal conductivity was compared with its vascular effect in dogs. In isolated, blood-perfused AV node preparations, a long-lasting increase in AV conduction time which culminated in second- or third-degree AV block at large doses occurred when DHP-218 was injected into the AV node artery, but not when injected into the artery that supplies the His-Purkinje-ventricular system. However, with DHP-218, a far longer-lasting increase in blood flow through both arteries occurred, and at smaller doses it occurred with little effect on AV conduction. In anesthetized, open-chest dogs of which heart rate was controlled at 150 beats/min, intravenous DHP-218 produced an initially rather quick and later very slowly developing and long-lasting fall in blood pressure. AV conduction time was prolonged only after the largest dose. The functional refractory period of the AV conduction system was rather shortened in all doses examined except for the largest dose. A marked increase in AV conduction time which culminated in third-degree AV block was seen in one of six dogs, only under conditions in which the heart was deprived of central neural control. These results indicate appreciable selectivity of DHP-218 for vasculature versus the AV node.

Neonatal tolerance induction in the thymus to MHC-class II-associated antigens. III. Significance of hemopoietic stem cells for induction and maintenance of Mls tolerance by continuous supply of tolerance-inducing nonlymphocytes

The role of hemopoietic stem cells and other cell types in the induction and maintenance of immunologic tolerance in the thymus was investigated by intravenous injection of Mls-semi-allogeneic cells into newborn mice less than 24 hr after birth. Mls-specific tolerance was induced by inoculation of peritoneal cells and thymus cells, and the tolerant state was compared with that induced by bone marrow cells which had hemopoietic stem cell activity and were able to create a stable chimera in both central and peripheral lymphoid organs. When peritoneal or thymus cells were injected, the level of tolerance attained was proportional to the number of cells injected, though peritoneal cells were 20 times as effective as thymus cells. In vivo functions of tolerance-inducing cells and their immediate precursors were radiosensitive and belonged to a Thy-1-, nylon-wool-nonadherent (probably non-B), weakly Sephadex G-10-adherent cell population. Tolerance induced by peritoneal cell injections was transient, starting to terminate within the first 2 weeks of life, while tolerance caused by bone marrow cell injections persisted through more than 6 weeks. Such transient tolerance induced by the former became long-lasting when followed by an additional injection of bone marrow cells, which did not cause thymic lymphocyte chimerism. All data indicated that bone marrow stem cells were engaged in tolerance induction and maintenance by continuously supplying tolerance-inducing nonlymphocytes.

Coronary vasodilator versus cardiac effects of MCI-176, a novel quinazolinone calcium antagonist, in the dog heart

We compared the coronary vasodilator and cardiac effects of MCI-176, a novel quinazolinone calcium antagonist, in isolated, blood-perfused sinoatrial (SA) node, atrioventricular (AV) node, and papillary muscle preparations of dogs. The drug was administered intraarterially. In SA node preparations MCI-176 reduced sinus rate and produced atrial standstill in large doses. In AV node preparations MCI-176 prolonged AV conduction time and produced second- or third-degree AV block in large doses only when administered into the artery supplying the AV node, but failed to affect AV conduction when administered into the artery supplying the His-Purkinje-ventricular system. In paced papillary muscle preparations MCI-176 reduced the force of contraction. In spontaneously beating papillary muscles MCI-176 failed to change the beating rate. MCI-176 increased blood flow in all preparations. The dose that doubled blood flow was slightly larger than the dose that produced a 15% increase in AV conduction time, but about one-third the dose that produced a 15% decrease in sinus rate. The dose estimated to reduce the force of contraction by half was more than approximately 10 times the dose that doubled blood flow. The results indicate that MCI-176 can be classified as a nonvasoselective calcium antagonist but that it differs from others.

Neonatal tolerance induction in the thymus to MHC-class II-associated antigens. I. Preferential induction of tolerance to Mls antigens and resistance to allo-MHC antigens

Neonatal tolerance inducibility of self-major histocompatibility complex (MHC)-class II-associated antigens was compared with that of allo-class II antigens. BALB/c (H-2d, Mlsb) mice, less than 24 hr after birth, were intravenously injected with bone marrow cells of either (BALB/c X DBA/2)F1 (H-2d, Mlsb/a, semiallogeneic at the Mls locus) or (BALB/c X B10.BR)F1 (H-2d/k, Mlsb; semiallogeneic at the MHC), as antigens. The mice were tested for in vivo immune activity of class II-reactive T cells by means of the popliteal lymph node-swelling assay. They developed tolerance, irrespective of type of antigens, showing profoundly suppressed host-versus-graft reaction, and those tolerized to the allo-MHC antigens accepted skin grafts of the corresponding allogeneic mice. In the thymus and spleen of the Mls-tolerant mice, antigen-specific class II-reactive T-cell activity was completely abolished, without the apparent involvement of suppressor cells. In contrast, the activity in allo-MHC-tolerant mice was not reduced in either thymus or peripheral lymphoid organs, suggesting that systemic hyporesponsiveness is attributable to reversible suppression of immune competent cells. The resistance for cell-level tolerance induction to allo-class II antigens may not be ascribed to the active participation of allo-MHC antigens in prevention of or in escape from tolerance induction or both, since an injection of bone marrow cells of both Mls and H-2-semiallogeneic (DBA/2 X B10.BR)F1 (H-2d/k, Mlsa/b) mice could induce tolerance to Mlsa-H-2d antigens in newborn thymus cells.

Neonatal tolerance induction in the thymus to MHC-class II-associated antigens. II. Significance of MHC antigens in anti-Mls tolerance

Specificity of anti-Mlsa tolerance induced in BALB/c (H-2d, Mlsb) neonates was investigated by a popliteal lymph node (PLN)-swelling assay for the local graft-versus-host (GVH) reaction by injecting tolerant thymus cells into the footpads of several types of F1 hybrid mice. When thymus cells were obtained from 1-week-old normal BALB/c, they evoked enlargement of PLNs of (BALB/c X DBA/2)F1 (H-2d, Mlsb/a) [CDF1] recipients and of other hybrid recipients, heterozygous in Mlsa,c,d alleles, irrespective of the major histocompatibility complex (MHC) haplotypes. The same thymus cells did not cause the response in MHC-heterozygous F1 hybrids when the hybrids were homozygous in Mlsb, identical with BALB/c mice. Therefore, the PLN response to Mls antigens, known to be closely associated with MHC-class II antigens, was not directed to the class II antigens themselves. This enabled us to examine the effects of MHC on tolerance induction to the Mls antigens. When BALB/c neonates were injected with CDF1 bone marrow cells, complete tolerance to Mlsa-H-2d antigens of CDF1 cells was induced in the thymus, while responsiveness to Mlsa antigens in the context of H-2k and H-2b antigens, was not affected. This indicates MHC-restriction of neonatal tolerance to Mls antigens. Furthermore, when Mls and H-2-heterozygous (BALB/c X AKR)F1 (H-2d/k, Mlsb/a) bone marrow cells served as the tolerogen, thymus cells of BALB/c neonates were also tolerized to Mlsa-H-2k antigens as well as to Mlsa-H-2d antigens, which suggests the involvement of MHC, probably class II antigens of tolerance-inducing cells.

Antinociceptive properties of a new tetrapeptide, Asn-Ala-Gly-Ala, in mice

The effect of intracerebroventricularly (i.c.v.) administered Asn-Ala-Gly-Ala (NAGA), a partial sequence of beta-lipotropin, was investigated using the tail-pressure, hot-plate and phenylbenzoquinone (PBQ)-induced writhing tests in mice. I.c.v. administration of NAGA produced a dose-dependent inhibition of responses as measured by the three different assays. The ED50 of NAGA on the tail-pressure test did not differ from that obtained on the hot-plate test. NAGA showed a prominent reduction in activity on the PBQ writhing as compared with the hot-plate and tail-pressure tests. A low dose of naloxone (0.1-1.0 mg/kg, s.c.) resulted in a dose-dependent antagonism of the effect of NAGA in all assays. These data suggest that the antinociceptive effect induced by NAGA may involve the endogenous opioid system in mice.

On the degradation of dermorphin and D-Arg2-dermorphin analogs by a soluble rat brain extract

Degradation of dermorphin, [D-Arg2]dermorphin and [D-Arg2, Gly3, Phe4]dermorphin in a soluble rat brain extract was examined. The former two heptapeptides were degraded in a similar fashion to produce corresponding N-terminal tetrapeptide as the main degradation product along with the parallel release of Tyr5, Pro6 and Ser7-NH2. Tyr-D-Arg-Phe-Gly showed a good enzymatic stability. When captopril, an angiotensin-converting enzyme inhibitor, was present in the incubation mixture, hydrolysis of the Gly4-Tyr5 bond was markedly suppressed and resulted in release of the corresponding N-terminal hexapeptide as the main degradation product. Combined use of captopril and amastatin, an aminopeptidase inhibitor, markedly suppressed the hydrolysis of these peptides. On the other hand, [D-Arg2, Gly3, Phe4]dermorphin was hydrolyzed easier than the other two heptapeptides and considerable amounts of Tyr1 and Phe4 were released after 20 hr incubation while the N-terminal tetrapeptide, Tyr-D-Arg-Gly-Phe, showed a good enzymatic stability. On the basis of these results, possible degradation pathways of these heptapeptides were discussed.

The analgesic activity of D-Arg2-dermorphin and its N-terminal tetrapeptide analogs after subcutaneous administration in mice

D-Arg2-dermorphin and its nineteen N-terminal tetrapeptide analogs were prepared, and their analgesic activities after subcutaneous administration in mice and the stability of a D-Arg2-dermorphin tetrapeptide to enzymatic degradation were examined. The analgesic effect was assessed by the tail pressure test. D-Arg2-dermorphin was found to have analgesic potency equal to or slightly greater than that of dermorphin. In a series of tetrapeptide analogs, a very pronounced activity greater than that of morphine was observed for analogs of the following structure, H-Tyr-D-Arg-Phe-X-OH (X = Gly, sarcosine and D-Ala) or its esters. Replacement of D-Arg2 by D-Arg(NO2), D-homoarginine or D-Lys resulted in a decrease in potency, suggesting that the guanidino group and side chain length of D-Arg2 are of great importance for a higher activity. D-Arg2-tetrapeptide (H-Tyr-D-Arg-Phe-Gly-OH) was found to be more stable than the parent tetrapeptide (H-Tyr-D-Ala-Phe-Gly-OH) to cleavage both by aminopeptidase M and by carboxypeptidase Y.

Autostimulatory adherent cells in the spleen of aging mice: characterization in the syngeneic host-versus-graft reaction

Enlargement of the popliteal lymph node (PLN) of 6-week-old mice were elicited by the footpad injection of spleen cells of sex-matched, syngeneic, older mice, but not of 6-week-old mice, in a fashion of host-vs.-graft reaction. Effective stimulating cells in the inoculum seem to be Ia-bearing adherent cells. On the other hand, neither B and T cells nor immunoglobulin-secreting cells were effective for host T cell stimulation. Among nonlymphocytic adherent cells, only those attached to plastic dishes after a 24 h-incubation, enriched in macrophages, showed the stimulatory activity for the young recipients, while cells which had adhered once but detached and became non-adherent during a 24 h-incubation or a crude non-macrophage fraction did not induce the PLN response. Thus, the age-related antigenic change may occur on macrophages but not on dendritic cells. The effective cells should be alive, heat-killed cells being impotent to elicite the response. Such spleen adherent cells of aged mice were found to be also stimulative for age-matched recipients, when they are older than 3 months. Autostimulation by macrophages might be responsible, at least in part, for the age-related change of immune functions.

Differential distribution of tolerogenic bovine gamma-globulin in lymphoid tissues

Deaggregated, tolerogenic bovine gamma-globulin was traced after intravenous injection into DDD mice. Amount of organ-distributed tolerogen varied among lymphoid organs such as spleen, thymus, axillary lymph node and femur bone marrow, probably depending on the amount of blood supply. On the other hand, the tolerogen elimination rate (TER) in these organs was almost the same as TER in blood, the half life being 2.6 days. Although the TER of tissue-associated tolerogen and of cell-associated tolerogen were also almost the same as that in blood, relative amount of cell-associated tolerogen differed among organs, the antigen amounts being 77 times higher in lymph node cells and 4 times higher in spleen and bone marrow cells than in thymus cells. These results are discussed in relation to the difference in the tolerance inducibility among lymphoid organs reported previously.

Distinctive effect of angiotensin II on prostaglandin production in dog renal and femoral arteries

The effect of angiotensin II (Ang II) on prostaglandin (PG) production in dog renal and femoral vasculature was examined in vivo and in vitro. In pentobarbital anesthetized dogs, the reduction of blood flow induced by intra-arterial infusion of Ang II was potentiated by pre-treatment with indomethacin (5 mg/kg) in the renal but not the femoral vasculature. Isolated renal and femoral arterial strips were incubated and the release of PGE2 and PGI2 (as 6-keto-PGF1 alpha) into the medium was measured by radioimmunoassay. Basal PGE2 and PGI2 production by renal and femoral arterial strips was approximately the same. PGI2 production was predominant for both strips. Ang II stimulated PG production in renal but not femoral arteries. In the renal artery, Ang II-induced PG production was inhibited by indomethacin (10(-6) M), mepacrine (10(-4) M) and saralasin (10(-6) M). These results suggest that Ang II stimulates PG production by the renal artery per se and the Ang II receptor is linked to phospholipase A2 in the renal but not the femoral artery.