Clinical characteristics of monochorionic twins with large hemoglobin level discordance at birth.

OBJECTIVES: To evaluate neonatal outcomes and clinical characteristics of monochorionic diamniotic (MCDA) twins with a large intertwin hemoglobin (Hb) difference at birth. METHODS: This was a retrospective cohort study of MCDA twin gestations delivered at Osaka Medical Center and Research Institute for Maternal and Child Health between 2003 and 2012. Cases of pregnancy termination, acardiac twins or intrauterine death were excluded. A large intertwin Hb difference at birth was defined as > 8.0 g/dL according to the postnatal criteria for twin anemia-polycythemia sequence (TAPS). The intertwin reticulocyte count ratio (RCR) was calculated by dividing the reticulocyte count of the anemic twin by that of the polycythemic twin. Cases with Hb differences were divided into two groups according to the RCR, TAPS when the RCR was > 1.7 and acute fetofetal hemorrhage (AFFH) when the RCR was ≤ 1.7. Neonatal outcomes were compared between the TAPS and AFFH groups. RESULTS: During the study period, 432 MCDA twin pregnancies of a total of 532 born at our hospital were analyzed. There were 12 (2.8%) cases of a large intertwin Hb difference. The median gestational age at birth of these cases was 34 (range, 23-38) weeks, and all were delivered by Cesarean section. There were seven (1.6%) cases of TAPS and five (1.2%) of AFFH. The neonatal survival rate was 91.7%; in one pair of twins with TAPS neonatal death occurred. All (100%) cases with TAPS and two (40%) with AFFH required blood transfusion or partial-exchange transfusion for at least one infant. CONCLUSIONS: Although the incidence of TAPS and AFFH may be low in MCDA twins, many affected neonates required treatment for hematological abnormalities. Delivery of MCDA twins via Cesarean section does not appear to prevent AFFH, despite the absence of labor.

Prevalence of radiographic lumbar spondylosis and its association with low back pain in elderly subjects of population-based cohorts: the ROAD study.

OBJECTIVES: Although lumbar spondylosis is a major cause of low back pain and disability in elderly people, few epidemiological studies have been performed. The prevalence of radiographic lumbar spondylosis was investigated in a large-scale population study and the association with low back pain was examined. METHODS: From a nationwide cohort study (Research on Osteoarthritis Against Disability; ROAD), 2288 participants aged > or =60 years (818 men and 1470 women) living in urban, mountainous and coastal communities were analysed. The radiographic severity at lumbar intervertebral levels from L1/2 to L5/S was determined by Kellgren/Lawrence (KL) grading. RESULTS: In the overall population the prevalence of radiographic spondylosis with KL> or =2 and > or =3 at the severest intervertebral level was 75.8% and 50.4%, respectively, and that of low back pain was 28.8%. Although KL> or =2 spondylosis was more prevalent in men, KL> or =3 spondylosis and low back pain were more prevalent in women. Age and body mass index were risk factors for both KL > or =2 and KL> or =3 spondylosis. Although KL = 2 spondylosis was not significantly associated with low back pain compared with KL = 0 or 1, KL> or =3 spondylosis was related to the pain only in women. CONCLUSIONS: This cross-sectional study in a large population revealed a high prevalence of radiographic lumbar spondylosis in elderly subjects. Gender seems to be distinctly associated with KL> or =2 and KL> or =3 lumbar spondylosis, and disc space narrowing with or without osteophytosis in women may be a risk factor for low back pain.

Prevalence of radiographic knee osteoarthritis and its association with knee pain in the elderly of Japanese population-based cohorts: the ROAD study.

OBJECTIVE: We investigated the prevalence of radiographic knee osteoarthritis (OA) and knee pain in the Japanese elderly using a large-scale population of a nationwide cohort study, Research on Osteoarthritis Against Disability (ROAD), and examined their association. METHODS: From the baseline survey of the ROAD study, 2,282 participants > or =60 years (817 men and 1,465 women) living in urban, mountainous and seacoast communities were analyzed. The radiographic severity at both knees was determined by the Kellgren/Lawrence (KL) grading system. KL> or =2 and KL> or =3 knee OA were examined separately to assess osteophytosis and joint space narrowing (JSN). RESULTS: The prevalence of KL> or =2 OA (47.0% and 70.2% in men and women, respectively) was much higher than that of previous studies in Caucasians, while that of KL> or =3 OA was not much different in men. Age, BMI, female sex and rural residency were risk factors for radiographic knee OA, knee pain and their combination. The prevalence of knee pain was age-dependent in women, but not in men. Knee pain was more strongly associated with KL> or =3 OA than with KL=2, and the association was higher in men than in women. Female sex was a strong risk factor even in the subgroup without radiographic knee OA (KL=0/1). CONCLUSION: The present cross-sectional study revealed a high prevalence of radiographic knee OA in the Japanese elderly. Knee pain was strongly associated with JSN especially in men, while women tended to have knee pain even without radiographic OA.

Epidemiology of lumbar osteoporosis and osteoarthritis and their causal relationship--is osteoarthritis a predictor for osteoporosis or vice versa?: the Miyama study.

SUMMARY: In a 10-year follow-up of a population-based cohort of Japanese subjects, incidences of and causal relationships between osteoporosis (OP) and osteoarthritis (OA) at the lumbar spine were clarified. OP might reduce the risk of subsequent OA at the spine in women, but not in men. INTRODUCTION: The aim of this study is to clarify the contribution of osteoarthritis (OA) to osteoporosis (OP) and vice versa. METHODS: A population-based, epidemiological study was conducted in a Japanese rural community. From 1,543 participants aged 40-79 years, 200 men and 200 women were selected and followed up for 10 years. Bone mineral density measurements were repeated after 3, 7, and 10 years, and X-rays were repeated after 10 years. RESULTS: The incidence of lumbar OP per 10,000 person-years for persons in their 40s, 50s, 60s, and 70s was 0, 0, 109.5, and 151.1 for men and 124.2, 384.0, 227.3, and 239.5 for women, respectively. The cumulative incidence of lumbar OA over 10 years aged 40-79 years was 25.8% in men and 45.2% in women. Cox's proportional hazards model showed no significant relationship between the presence of lumbar OA at the baseline and incidence of lumbar and femoral neck OP in both genders. A significant relationship was demonstrated between the presence of lumbar OP, not femoral neck OP, at the baseline and cumulative incidence of lumbar OA in women (odds ratio, 0.20; 95% confidence interval, 0.05-0.80; P = 0.02). CONCLUSION: OP in women appears to reduce the future incidence of OA at the lumbar spine.

Fully automatic quantification of knee osteoarthritis severity on plain radiographs.

OBJECTIVE: Although knee osteoarthritis (OA) is a major public health issue causing chronic disability, there is no objective or accurate method for measurement of the structural severity in general clinical practice. Here we have established a fully automatic program KOACAD (knee OA computer-aided diagnosis) to quantify the major OA parameters on plain knee radiographs, validated the reproducibility and reliability, and investigated the association of the parameters with knee pain. METHODS: KOACAD was programmed to measure joint space narrowing at medial and lateral sides, osteophyte formation, and joint angulation. Anteroposterior radiographs of 1979 knees of a large-scale cohort population were analyzed by KOACAD and conventional categorical grading systems. RESULTS: KOACAD automatically measured all parameters in less than 1s without intra- or interobserver variability. All parameters, especially medial joint space narrowing, were significantly correlated with the conventional gradings. In the parameters, osteophyte formation was associated with none of the joint space parameters, suggesting different etiologic mechanisms between them. Multivariate logistic regression analysis after adjustment for age and confounding factors revealed that medial joint space narrowing and varus angulation of knee joints were risk factors for the presence of pain (594/1979 knees), while neither lateral joint space nor osteophyte area was. CONCLUSION: KOACAD was shown to be useful for objective, accurate, simple and easy evaluation of the radiographic knee OA severity in daily clinical practice. This system may also serve as a surrogate measure for the development of disease-modifying drugs for OA, just as bone mineral density does in osteoporosis.

The liver and the hematolymphoid system: I. The regulation of nylon-passed spleen cell proliferation by active factors released from syngeneic nonparenchymal liver cells.

Nylon-passed spleen cells were found to proliferate when cultured with syngeneic nonparenchymal adherent liver cells and their culture supernatants. The supernatants contained IL-1, IL-6, GM-CSF, and IFN (alpha + beta) activities but not IL-2 and IL-3 activities. The IFN level was higher in early culture sup (2-24 hr) than in later culture sup (48-72 hr). Proliferation was greatly increased by anti-IFN (alpha + beta) serum in the spleen cells cultured in the earlier sup. This antiserum increased the spleen cell proliferation only slightly in the later culture sup. This suggests that nonparenchymal liver cells produce two factors, one having a suppressor, and the other an enhancer action, with IFN being one of the suppressor factors. With culture time, DNA synthesis of spleen cells increased and IL-2 and IL-3 activities were generated in the culture sup. Cells proliferated during culture were found to be morphologically lymphocytes, granulocytes, and macrophages. The mechanisms by which nonparenchymal liver cells regulate the hematolymphoid system are discussed based on our observations.

Role of the liver in T cell differentiation--generation of CD3-CD4+/CD8+TCRbeta- cells and CD3-4-8-TCRbeta+ cells from CD4-8-TCRbeta- athymic nude bone marrow cells by culture with parenchymal liver cells.

To investigate the influence of the liver on differentiation of hematopoietic stem cells/pro-T cells, TN-NWP-BMC (athymic nude bone marrow cells that were treated with anti-TCRbeta, anti-CD4, and anti-CD8 Abs plus complement and then passed through a nylon wool column) were cultured on parenchymal liver cells. After culture for 2.5 days, CD3-4-8-TCRbeta+ cells and CD3-CD4+/CD8+TCRbeta- cells were developed from TN-NWP-BMC. TCRVbeta8+ cells comprised 19.9% of CD3-4-8-TCRbeta+ cells, and Vbeta8 mRNA was detected in the CD3-4-8-TCRbeta+ cells by reverse transcriptase-polymerase chain reaction. The CD3-CD4+/CD8+TCRbeta- cells contained not only single-positive cells but also CD4+8+ double-positive cells. The CD8 protein consisted of 88.9% CD8alpha+beta-, 10.1% CD8alpha+beta+, and 1% CD8alpha-beta+ molecules. From these results and the finding of co-expressed antigens, CD3-4-8-TCRbeta+ cells and CD3-CD4+/CD8+TCRbeta- cells appear to be immature cells not committed to a certain cell lineage.

Production of macrophage colony-stimulating factor by adult murine parenchymal liver cells (hepatocytes).

The activity of macrophage colony-stimulating factor (M-CSF) was found in the culture supernatant of mouse parenchymal liver cell fractions in a bone marrow colony-forming assay. The activity of an M-CSF-like substance purified by a four-step procedure was neutralized by goat anti-mouse M-CSF antiserum. M-CSF mRNA was detected in cellular RNA prepared from cultured parenchymal liver cell fractions by Northern blot analysis and also in cultured parenchymal liver cells by in situ hybridization. These results indicate that parenchymal liver cells have the capacity to produce M-CSF. We discuss the role of M-CSF in hematopoiesis, the immune response, and other biological phenomena.

Novel mutation in exon 18 of the cartilage oligomeric matrix protein gene causes a severe pseudoachondroplasia.

Pseudoachondroplasia (PSACH) is a common skeletal dysplasia characterized by disproportionate short stature, early-onset osteoarthrosis, and dysplasia of the spine, epiphysis, and metaphysis. Multiple epiphyseal dysplasia (MED) is a similar but less severe disorder characterized by dysplasia of the epiphysis. Both disorders are caused by mutations in the cartilage oligomeric matrix protein (COMP) gene. COMP mutations cluster in a region of the gene that encodes calmodulin-like repeats (CLRs) and correlate closely with disease severity. Typically, mutations in exon 13 that composes the seventh CLR produce severe PSACH phenotypes, whereas mutations found elsewhere in the gene produce mild PSACH or MED phenotypes. We have identified a PSACH patient carrying a novel mutation in exon 18 of COMP that composes the C-terminal globular domain. This mutation produced a severe PSACH phenotype with marked short stature and deformities of the spine and extremities. Our results extend the range of disease-causing mutations within the COMP gene and demonstrate the importance of the additional domain of COMP protein in its in vivo function.

[Liver regeneration and immune system--morphological and cytochemical studies of activated spleen cells during the liver regeneration after partial hepatectomy].

Morphological and cytochemical changes were investigated in spleen cells after 70% hepatectomy in mice. During liver regeneration after the hepatectomy, the spleen weight gradually rose to a peak at 6 day. In the spleen, the number of POD-positive myelocytic cells and NCAE-positive granulocytic cells also reached a peak 4 days after the operation and then decreased. On the other hand, ANBE-positive monocytic cells gradually increased up to 9 day and didn't decrease for this period. On day 9 of the culture, the boundary between the red and the white pulps of the spleen became unclear. In this spleen, the clusters of blast cells were sporadically observed. Splenic T cells cocultured with nonparenchymal adherent normal liver cell or nonparenchymal adherent normal liver cell supernatant developed into granulocyte colonies in earlier periods and monocyte colonies in later periods. These findings suggest that the factors released from liver cells may regulate strictly spleen cell activation. Blast cell formation in the culture with nonparenchymal adherent normal liver cell supernatant was amplified by anti interferon (alpha + beta) antibody. These facts indicate that the functional network of cytokines is formed by the interaction of various cytokines (IL-1, IL-6, CSF, IFN, etc.) in nonparenchymal adherent normal liver cell supernatant.

Association between height loss and bone loss, cumulative incidence of vertebral fractures and future quality of life: the Miyama study.

INTRODUCTION: The study aimed to clarify associations between height loss, bone loss and the quality of life (QOL) score among general inhabitants of Miyama, a rural Japanese community. This population-based epidemiological study was conducted in Miyama, a village located in a mountain area in Wakayama Prefecture, Japan. METHODS: A list of all inhabitants comprising 1,543 inhabitants (716 men, 827 women) born in this village between 1910-1949 was compiled. From the above whole cohort, a subcohort to measure bone mineral density (BMD) was recruited, consisting of 400 participants, divided into four groups of 50 men and 50 women each, and stratified into age decades by decade of birth-year (1910-1919, 1920-1929, 1930-1939 or 1940-1949). BMD measurement, physical measurements of height (cm) and body weight (kg) were taken, and body mass index (BMI; kg/m(2)) were calculated. BMD and anthropometric measurements were repeated on the same participants at 3, 7 and 10 years after baseline measurement (1993, 1997 and 2000). RESULTS AND DISCUSSION: Among 299 of 400 participants, changes in height over 10 years for men in their 40s, 50s, 60s and 70s were -0.7 cm, -0.5 cm, -1.2 cm and -1.5 cm, respectively, compared with -0.7 cm, -1.4 cm, -2.1 cm and -3.7 cm in women, respectively. No significant relationships between change in height and rate of change in BMD at the lumbar spine and femoral neck after adjustment for age in men (lumbar spine, beta = 0.058, standard error of the mean (SE) = 0.031, P = 0.501, R(2) = 0.038; femoral neck, beta = 0.100, SE = 0.038, P = 0.228, R(2) = 0.121) were identified. By contrast, among women, a significant positive association was identified between height change and change rate of BMD at the lumbar spine after adjusting for age (beta = 0.221, SE = 0.039, P = 0.012, R(2) = 0.069), while no significant relationship was found between height change and change rate at the femoral neck (beta = 0.107, SE = 0.039, P = 0.229, R(2) = 0.048). No significant relationship was noted between vertebral fractures (VFx) and height at baseline in men and women (men: odds ratio (OR) 0.93, 95% confidence interval (CI) 0.81-1.05, P = 0.24; women: OR 0.97, 95% CI 0.87-1.08, P = 0.58) or between VFx and height loss (men: OR 1.31, 95% CI 1.00-1.71, P = 0.051; women: OR 1.20, 95% CI 0.94-1.53, P = 0.14). In both men and women, no significant relationship was identified between utility of the EuroQol EQ5D questionnaire and height at baseline (men: beta = -0.148, SE = 0.003, P = 0.202, R(2) = 0.076; women: beta = 0.127, SE = 0.004, P = 0.235, R(2) = 0.048), and height change (men: beta = -0.078, SE = 0.008, P = 0.452, R(2) = 0.065; women: beta = 0.053, SE = 0.010, P = 0.608, R(2) = 0.038).

Separation of RRBC-RFC and non-rosette forming cells (non-RFC) of guinea pig T-cell populations and their functional difference. 1. Response of RRBC-RFC and non-RFC to either Con-A or LPS.

Guinea pig lymph node cells suspension (LNC-O) was filtered through a glass wool column and the effluent (LNC-G) was further filtered through a nylon column. In this effluent (LNC-NE) about 30 per cent of the lymphocytes was identified as non-rosette forming cells (non-RFC). The non-RFC fraction was separated from LNC-NE fraction by Ficol-Conray specific gravity centrifugation or effluent cells reacted previously to rabbit red blood cells (RRBC). The upper layer after centrifugation, designated non-RFC fraction, was separated. In this fraction 96% of the cells were lymphocytes and about 95% of them were non-RFC, which lacked receptors for rabbit red blood cells (RRBC) or EAC and detectable surface immunoglobulin by conventional techniques. Though the response of the lymphocytes in the non-RFC fraction to mitogenic (Con-A, LPS) or antigenic stimulation was lower in comparison with that in RFC-rich fraction, the response of non-RFC to ConA exceeded the response to LPS. These facts suggest that at least a portion of the non-RFC may be cells from the T-cell line.

[Modification of surface phenotype and function in intrahepatic lymphocytes during liver regeneration after partial hepatectomy].

In the intrahepatic lymphocyte fraction (IHL) of mice whose livers have been perfused by Ca+2 and Mg+2 free Hank's balance salt solution, flow cytometric analysis reveals various cells similar to those found in the spleen (CD3+ cell, CD4+ cell, CD8+ cell, alpha beta TCR+ cell, gamma delta TCR+ cell, Thy1.2+ cell, B220+ cell and asialo-Gm1+ cell). The cytotoxic activity against YAC-1 cells in IHL is significantly higher than that in spleen cells. Furthermore, IHL has cytolytic activity against syngeneic thymoma BW5147 cells which is not found in spleen cells. Both cytotoxic activities of IHL are greatly weakened by the pretreatment of IHL with anti asialo-Gm1 Ab and rabbit complement. During liver regeneration after a partial hepatectomy, the percentages of lymphocyte subsets of IHL such as alpha beta TCR+ cells, gamma delta TCR+ cells and asialo-Gm1+ cells transiently increase 2 days after the partial hepatectomy and their cytotoxic activities against YAC-1 and BW5147 cells also reach a peak at that time. It is well known that the peak of mitotic index in regenerating parenchymal liver cells peaks 2 days after a partial hepatectomy and that the number of Pit cells peaks 10 to 14 days after. Compared with the time for reaching the highest mitotic index in regenerating parenchymal liver cells, the proliferation of Pit cells comes very late. It has not been clear which proliferation process in parenchymal liver cells is suppressed by activated Pit cells. Our findings in this paper reveal that the percentages and the cytotoxic activities of asialo-Gm1+ cells in IHL reach their peak 2 days after an operation.(ABSTRACT TRUNCATED AT 250 WORDS)

Adhesive interaction between lymphocytes and sinusoidal liver cells.

Since sinusoidal liver cells directly interact with circulating hemopoietic cells and lymphocytes, Kupffer cells may have the capacity to trap and activate these cells in the liver microcirculation. In order to investigate the adhesion mechanism of Kupffer cells to other lymphoid cells, mouse sinusoidal liver cells were isolated by a collagenase perfusion followed by differential centrifugations. By in vitro adhesion assay of lymphocytes to sinusoidal liver cells and staining of adhered lymphocytes with FITC/peroxidase labeled peanut agglutinin (PNA), the following observations were made: 1) Lymphocytes from various lymphoid organs including the liver itself adhered to Kupffer cells. 2) After an incubation period, DNA synthesis of the adhered lymphocytes increased. 3) A high percentage of the adhered lymphocytes were PNA+ cells. 4) D-Galactose, a PNA specific carbohydrate, inhibited the lymphocyte binding and the total DNA synthesis of the adhered lymphocytes decreased proportionally with their decrease in number. Our results suggest that sinusoidal liver cells may have the ability to trap and to activate PNA+ cells.

Antigen-specific T cell cluster formation on antigen-pulsed macrophage monolayers in mice.

We describe the quantitative measurement of antigen-specific clusters formed by antigen-pulsed macrophages and immunized T cells in mice. We have found the peripheral blood T cells show very little non-specific adhesion to macrophages in mice. By using this population of lymphocytes in the peripheral blood as the source of immunized T cells, we could quantitate antigen-specific cluster formation. On OVA-pulsed monolayers of peritoneal exudate macrophages from normal BALB/c mice, syngeneic peripheral blood T cells from donors immunized with the same antigen develop 20-40 clusters per 1,000 macrophages, whereas the same T cells on non-pulsed monolayers develop only 0-5 cluster-like accumulations of cells. On antigen-pulsed monolayers of macrophages from allogeneic (C57BL/6 or A/J) mice, clusters are developed only in the negative range (0-5/1,000 macrophages). Considering the observation by Braendstrup et al, these data seem to suggest that histocompatibility between macrophages and T cells is required to develop antigen-specific T cell clusters on antigen-pulsed macrophage monolayers, and that the genetic restriction of immune responsiveness may be directly expressed in this initial form of cellular interaction between antigen-bearing macrophages and specific T cells.

Characteristic immunological tolerance in intrahepatic lymphocytes induced by bacterial superantigen SEB.

We have reported that the liver is closely associated with the hematolymphoid system and that the liver, as a lymphoid organ, may play an important role in the differentiation of lymphocytes and oral tolerance. To investigate the relevance of the liver to immunological tolerance, we compared the response pattern to Staphylococcus enterotoxin B (SEB) in intrahepatic lymphocytes (IHL) with those of spleen cells (SPC) and mesenteric lymph node cells (mLNC) during tolerance induction. Tolerance was induced by i.v. injections of SEB in all three organs. IHL had a distinct pattern from the other cells in the induction of unresponsiveness to SEB. While SPC and mLNC have a proliferation phase before the reduction of DNA synthesis, IHL become tolerant immediately without this phase. When IHL became tolerant in the early period after SEB injection, their nylon-wool column non-adherent (NW-NA) IHL were not recovered from unresponsiveness in vitro in spite of the addition of irradiated normal SPC as accessory cells. NW-NA IHL did not secrete IL-2 during this process, indicating that NW-NA IHL were in a state of functional anergy soon after the i.v. administration of SEB. Phenotypic analysis revealed that the characteristic changes of IHL during the induction of unresponsiveness might be associated with the kinetic modulation of CD4+ V beta 8+ T cells. These results suggest that the liver may hold a different mechanism for the induction of tolerance to SEB from that of SPC and mLNC.

Partial purification, physicochemical characterization and biological function of a rosette-decreasing factor (RDF) extracted from guinea pig thymus.

A factor that decreases rosette formation between guinea pig T-cells and rabbit red blood cells (RRBC) was extracted from the thymus of the guinea pig. The active factor could be extracted from the spleen as well as the thymus, but not from the liver or kidney. The active factor of the thymic extract was found in the precipitates produced by 80% saturated ammonium sulfate and it was separated from the water-soluble fraction of the precipitates. The molecular weight of the partially purified substance was estimated to range between 10,000 and 30,000 by filtration through a diaflow membrane. From the studies on physicochemical characterization, it might be a heat-resistant basic peptide probably bound to a ribonucleotide moiety. This factor reduced rosette formation between RRBC and guinea pig T-cells, but did not reduce erythrocyte-antibody-complement rosette formation. This factor also inhibited mitogen (concanavalin A, phytohemagglutinin-P)- induced DNA synthesis of guinea pig lymphocytes and antigen-induced DNA synthesis of sensitized guinea pig lymphocytes.

Suppression of IgE antibody response by preadministration of antigen-pulsed spleen cells. II. Characteristics of immediate tolerance induction.

Intravenous administration of syngeneic spleen cells (SPC), briefly pulsed with antigen in vitro, resulted in a profound state of IgE antibody unresponsiveness. One of the mechanisms of this unresponsiveness is responsible for an immediate tolerance which is induced without any suppressor cells. Characteristics of this immediate tolerance were investigated. Administration of antigen-pulsed spleen cells 4 h before the immunization, suppressed the production of IgE antibody triggered by the subsequent immunization. Pretreatment with cyclophosphamide had no effect on this rapid suppression, and this suppressive state could not be transferred to normal syngeneic recipients by the injection of spleen cells from the tolerant mice used in our experiment. These observations suggest that suppressor cells do not play an important role in immediate tolerance. The extent of this immediate tolerance induced by the injection of antigen-pulsed SPC depends on the number of antigen-pulsed SPC and the dose of antigen to which SPC had been exposed. Injection route of antigen-pulsed SPC has a great influence on the induction of immediate tolerance. The order of suppressive extent is intravenous, greater than intraperitoneal greater than subcutaneous. This suppression is specific to the antigen pulsed to SPC. Carrier-specific T cells are the major target of suppression in immediate tolerance. Antigen-pulsed T cells induce immediate tolerance most effectively in the subpopulations of SPC.