Lifestyle determinants for social activity levels among the Japanese elderly

We conducted a self-administered questionnaire survey to a total of 5239 elderly persons in four areas in Japan in 1993, which inquired about past lifestyles and present social activities. Based on the survey data, we first developed social activity measures, and then examined associations of the present total social activity measure with past lifestyles and physical conditions. The lifestyles significantly associated with high social activity after 65 years of age were 'high educational attainment'; having been 'healthy', 'plump', 'physically active' and 'having had hobbies' at about 50 years of age; and having 'frequent intake of many kinds of foods' during 30-50 years of age. Intake during 30-50 years of age of Japanese-style foods (rice, soybean paste soup, bean curd, pickles), noodles, beans, plant roots and potatoes was not significantly linked with the social activity levels at old age in either males or females. The same was true for smoking and drinking habits at about 50 years of age. Our findings essentially suggest the importance of a positive attitude at middle age to maintain and promote health status and improve lifestyles in order to attain high social activity at old age.

Pervanadate stimulation of wortmannin-sensitive and -resistant 2-deoxyglucose transport in adipocytes

Pervanadate mimics several distinct insulin effects, including stimulation of hexose uptake in the in vitro system, and reduces the blood glucose level in streptozotocin-treated diabetic rats. It has been proposed that pervanadate induces insulin-like effects mediated through autophosphorylation and activation of insulin receptor (IR) even in the absence of insulin by inhibiting protein tyrosine phosphatases. This study focused on the mechanism of pervanadate action on hexose uptake. Both insulin (100 nM) and pervanadate (100 microM), a protein tyrosine phosphatase inhibitor, induced a marked increase in the phosphorylation at tyrosine residues of IR and insulin receptor substrate 1 (IRS-1) and in 2-deoxyglucose uptake in 3T3-L1 adipocytes. Wortmannin (1 microM), a specific phosphatidylinositol 3-kinase (PI 3-kinase) inhibitor, inhibited the increased 2-deoxyglucose uptake by insulin completely but that by pervanadate only partially. On the other hand, both insulin- and pervanadate-stimulated PI 3-kinase activities were inhibited completely by wortmannin (100 nM), suggesting that the pervanadate-induced wortmannin-resistant effect on hexose uptake may be mediated through a PI 3-kinase-independent pathway. This pervanadate-induced wortmannin-resistant effect was abolished by ST-638, a specific tyrosine kinase inhibitor. These data suggest that at least two distinct tyrosine phosphorylation pathways may be involved in the insulin-like effect of pervanadate.

Effect of the selective CCKB receptor antagonist LY288513 on conditioned fear stress in rats

In order to investigate the involvement of cholecystokinin (CCK) in the regulation of anxiety, the effect of the selective non-peptide CCKB receptor antagonist LY288513 ((4S, 5R)-N-(4-bromophenyl)-3-oxo-4,5-diphenyl-1-1-pyrazolidinecarboxamide+ ++) on freezing behavior induced by conditioned fear stress was examined using a time-sampling procedure. Rats were individually subjected to 5 min of inescapable electric footshock in a shock chamber. Twenty-four hours after the footshock, the rats were again placed in the shock chamber and observed for 5 min without shocks: this procedure is termed conditioned fear stress. Subcutaneous administration of LY288513 30 min before footshock (0.3 mg/kg) and 30 min before conditioned fear stress (0.03 mg/kg) reduced conditioned freezing. This indicates that LY288513 blocked both the acquisition and expression of conditioned fear. The relatively selective non-peptide CCKA receptor antagonist, lorglumide (D, L-4-(3,4-dichlorobenzoylamino)-5-(diphentylamino)-5-oxo-pent anoic acid), blocked the expression of conditioned fear, though only at a high dose (1.0 mg/kg). The peripheral non-peptide CCKA/B receptor antagonist, loxiglumide (D, L-4-(3,4-dichlorobenzoylamino)-5- (N-3-methoxypropyl-pentylamino)-5-oxo-pentanoic acid), failed to do so. These results suggest that brain CCKB receptors are involved in the regulation of anxiety.

Hemorrhage and abnormal veins in acoustic neurinoma: MR findings

We reviewed the MR imaging findings of 57 acoustic neurinomas which were verified at surgery or diagnosed on the basis of neuroradiological and neurootological data. Two uncommon MR findings of acoustic neurinoma were found. First, hypointense areas were observed on T2-weighted images in five of the 12 tumors larger than 25 mm in diameter. These hypointense areas represented hemosiderin deposition secondary to occult intratumoral hemorrhage. Second, curvilinear or round signal voids were noted at the periphery of 11 large or medium-sized tumors, and these corresponded to "abnormal veins" seen on angiographic studies.

Functional disturbance of naive T lymphocytes in very high IgE producers: depletion of interleukin-4-induced interleukin-4-producing cells

We examined the capacity of T cells from normal individuals and allergic patients with very high IgE to differentiate into interleukin-4(IL-4)-producing cells in vitro. T cells incubated with anti-CD3 monoclonal antibody plus IL-4 or plus anti-IL-4 antibody in the presence of antigen-presenting cells for 7 days were restimulated and their capacity to express IL-4 mRNA was examined by RT-PCR. In T cells from normal individuals, there was a marked increase in the expression of IL-4 mRNA following the addition of IL-4. After fractionation of normal T cells into naive T (CD45RA+) and memory T (CD45RO+) cells, induction of the increase of IL-4 mRNA was restricted to the naive T cell population. In contrast, in T cells from allergic patients, the stimulation of whole or naive T cells with anti-CD 3 monoclonal antibody in the presence of IL-4 induced much less IL-4 mRNA. These findings suggest the presence of a functional abnormality in IL-4-dependent development of IL-4-producing T cells in the peripheral-blood naive T cells from allergic patients.

Expression of c-fms proto-oncogene product by ovarian cancer cell lines with effects of macrophage colony-stimulating factor on proliferation

We studied the production of macrophage colony-stimulating factor (M-CSF) and the expression of c-fms mRNA, an M-CSF receptor, in four human ovarian cancer cell lines. All four cell lines expressed c-fms mRNA while three secreted M-CSF into the culture medium. The exogenous administration of M-CSF caused no significant enhancement of cellular proliferation in any cell line. Interestingly, the proliferation of KK cells was not affected by anti-M-CSF antibody. These results, taken together with the fact that ovarian cancer cells simultaneously produce M-CSF and c-fms, suggest that an autocrine mechanism may modulate cellular proliferation.

Phenotypic change and proliferation of murine Kupffer cells by colony-stimulating factors

Kupffer cells were isolated from C57BL/6 mice by collagenase perfusion and assessed for response to colony-stimulating factors (CSFs) in terms of their phenotypic change and proliferation. Kupffer cells expressed F4/80, but not Mac-1, CD71, or asialo-GM1 initially. This phenotype pattern was different from that of alveolar and peritoneal macrophages. After stimulation with recombinant human macrophage CSF (M-CSF) or mouse granulocyte-macrophage CSF (GM-CSF), Kupffer cells expressed Mac-1 and a low level of CD71 in addition to F4/80 and increased in phagocytotic activity in association with the expression of CR3. Both M-CSF and GM-CSF, but not human IL-3, induced the proliferation of Kupffer cells in a dose-dependent manner, and after 7 days, the number of the cells increased to about four to six times the initial number. The relatively high dose of GM-CSF downmodulated the M-CSF receptor on Kupffer cells and inhibited the cell proliferation induced by the optimal dose of M-CSF. These data indicated that murine Kupffer cells have a different phenotype from other macrophages and that they respond to M-CSF and GM-CSF, leading to functional maturation and proliferation.

Early and transient increase in oxidative stress in the cerebral cortex of senescence-accelerated mouse

Age-related changes in oxidative stress in the cerebral cortex of SAMP8, a substrain of senescence-accelerated mouse (SAM), were investigated in comparison with those in SAMR1, which were used as a control. The lipid peroxide and protein carbonyl contents were transiently increased in SAMP8 from 4- to 8-weeks of age. The increases in lipid peroxide were seen only in the cerebral cortex and not in other regions of the cerebrum. Furthermore, the net generation of reactive oxygen species in cerebral cells was also increased in SAMP8. In addition, the activity of glutamine synthetase, which is known as an enzyme-highly sensitive to reactive oxygen, was decreased in the cerebral cortex of SAMP8 from 4- to 8-weeks of age. These results suggest that oxidative stress may be induced in the cerebral cortex of SAMP8 from 4- to 8-weeks of age, preceding the appearance of distinctive deficits in the brain of SAMP8.

Structure of a galactan from cell walls of Bifidobacterium catenulatum YIT4016

A structural study was carried out on a galactose-rich polysaccharide fraction isolated from cell walls of Bifidobacterium catenulatum YIT4016 after N-acetylmuramidase digestion. The polysaccharide contained galactose and glucosamine in a molar ratio of 16.9:1.0. Data obtained by 13C NMR spectroscopy showed that the backbone chain of this polysaccharide is composed of galactofuranose residues, while the branches consist of galactopyranosyl residues. Furthermore, the data obtained from NaIO4 oxidation, partial methanolysis and methylation analysis indicated that this polysaccharide consists of a trisaccharide repeating unit having the following structure: [sequence: see text]

Evidence for progenitors of chronic lymphocytic leukemia B cells that undergo intraclonal differentiation and diversification

Peripheral blood mononuclear cells from five patients with IgG+ B-type chronic lymphocytic leukemia (B-CLL) were analyzed for the presence of clone-specific Ig H chain variable region gene mRNA transcripts linked to C mu and/or C alpha. This was assessed by (1) comparing the lengths of portions of the VHDJH of the IgG+ CLL clones with those of the mu and alpha isotype-expressing B cells, (2) performing clone-specific endonuclease digestion studies, and (3) determining the DNA sequences of the mu and alpha isotype-expressing cDNA. Thus, when B-cell mRNA from these five patients were reverse transcribed with C gamma-specific primers and then amplified by polymerase chain reaction, dominant cDNA were found with lengths corresponding to those of the IgG+ CLL B cell. In addition, in four cases, cDNA of lengths identical to those of the CLL B cell were detected when mRNA was reverse transcribed and amplified using c mu- and/or C alpha-specific primers, strongly suggesting clonal relatedness. These CLL-related mu- and alpha-expressing cDNA were present in greater amounts that unrelated (non-CLL) mu- and alpha-expressing cDNA from normal B cells that used genes of the same VH family. When the sequences of these CLL-related C mu- and C alpha-expressing cDNA were compared with those of the IgG+ CLL clones, it was clear that they were derived from the same ancestral gene as the IgG-expressing CLL B cell, thus documenting their common origin. Finally, nucleotide point mutations were observed in the mu- and alpha-expressing cDNA of certain patients, indicating divergence with the CLL. These data suggest that IgM+ B cells, which are precursors of the leukemic B cells, exist in increased numbers in the blood of most patients with IgG+ B-CELL and that these cells may differentiate, accumulate V genes mutations, and undergo isotype switching in vivo. In addition, the data are consistent with a sequential-hit model for the evolution of CLL.

Macrophage colony-stimulating factor induces interleukin-8 production in human monocytes

We have investigated the stimulatory effect of recombinant human macrophage colony-stimulating factor (rhM-CSF) on interleukin-8 (IL-8) production by human peripheral blood monocytes. When monocytes were prepared from peripheral blood and cultured for 24 hours, the average amount of IL-8 in the culture medium was about 8.9 +/- 3.2 ng/2 x 10(5) cells. In contrast, the production of IL-8 by monocytes increased to a level of 19.2 +/- 4.7 ng/2 x 10(5) cells in response to rhM-CSF. This induction by rhM-CSF was dose-dependent. Northern blot analysis showed that expression of IL-8 at the pretranslational level was enhanced after M-CSF treatment. Kinetic studies showed that secretion of IL-8 from monocytes was enhanced within 2 hours after exposure to rhM-CSF, and a saturation level, which was reached around 48 hours, was two-fold higher than that of cells without M-CSF treatment. In addition, conditioned medium of M-CSF-stimulated monocytes activated the chemotaxis of human neutrophils, and this activity was significantly inhibited by anti-IL-8 antibody. These results, taken together, suggest that M-CSF can affect many cellular functions through regulation of IL-8 expression in monocytes.

Exotoxin A stimulates fluid reabsorption from distal airspaces of lung in anesthetized rats

To determine whether exotoxin A may affect the transport of fluid across the lung epithelium, two isogenic strains of Pseudomonas aeruginosa PA103 (10(8) colony-forming units), one (PA103 tox omega) with a structural gene mutation in exotoxin A, were instilled into the distal airspaces of anesthetized rats. PA103 parental strain, but not its mutant, stimulated the removal of fluid from the distal airspaces of the lung. Instillation of exotoxin A alone caused a dose-dependent increase in the fluid transport across the lung epithelium. Instillation of amiloride (10(-3) M) with exotoxin A demonstrated that this effect partially depended on increased uptake of sodium across the lung epithelium. The absence of stimulation after instillation of an exotoxin A mutant (PE delta Glu553) without ADP-ribosyltransferase activity demonstrated that the effect of exotoxin A depended on its ADP-ribosyltransferase activity. Finally, the instillation of exotoxin A in rats depleted of macrophages indicated that the effect of exotoxin A was not secondary to the activation of alveolar macrophages by this toxin. In conclusion, these results indicate that the in vivo release of exotoxin A by live airspace P. aeruginosa directly stimulates the fluid removal from the airspaces by the lung epithelium. This may alter the volume or composition of airway secretions, and may contribute to the lung disease in patients infected with P. aeruginosa.

Superficial siderosis--a cause of audiovestibular failure

Bilateral vestibular end organ failure in adult life is a rare condition with some specific known causes, such as relapsing polychondritis, autoimmune inner ear disease, Lues venerium, and an acute effect of gentamicin. This case report draws attention to a rare condition that is potentially recognizable early in its development. The patient has superficial siderosis, which is iron deposits over the cerebrum, resulting in progressive neurologic failure involving all of the systems. Early in its course before other symptoms appear, there is development of progressive hearing loss and vestibular failure. This case report and literature review are given, including a potential for attempts at therapy if the disorder is recognized early.

Cervical intra-epithelial neoplasia (CIN) III of the uterine cervix in a young female associated with AIDS

A case of cervical intraepithelial neoplasia (CIN) III implying severe dysplasia or carcinoma in situ of the uterine cervix in a 24 year old Japanese female patient with acquired immunodeficiency syndrome (AIDS) is reported. Autopsy revealed marked systemic atrophy of lymph nodes, Pneumocystis carinii pneumonia, pulmonary aspergillosis, acute pancreatitis and CIN III of the portio vaginalis uteri. The human papillomavirus (HPV) genome was detected in sections of the CIN III by polymerase chain reaction. This is the first autopsy report of cervical neoplasia in a patient with AIDS in Japan, and the pathogenesis of CIN III in this case was associated with HPV infection. Gynecological examination should be mandatory for female patients with human immunodeficiency virus infection.

Serotonin reuptake inhibitors reduce conditioned fear stress-induced freezing behavior in rats

Conditioned fear stress (CFS)-induced freezing behavior has been proposed as an animal model of anxiety. In the present study, freezing was used to determine the anxiolytic activity of selective serotonin reuptake inhibitors (SSRIs), which are reported to be clinically effective in anxiety disorders. The duration of freezing behavior was reduced by acute treatment with the SSRIs citalopram (1-10 mg/kg) and fluvoxamine (3-30 mg/kg). Acute treatment with the serotonin (5-HT)/noradrenaline (NA) mixed reuptake inhibitor milnacipran (3-30 mg/kg) also attenuated CFS-induced freezing, while acute treatment with the NA reuptake inhibitors maprotiline and ORG4428, and the dopamine (DA) reuptake inhibitor GBR12909 failed to alter CFS-induced freezing. These results indicate that facilitation of 5-HT availability in the brain produced by 5-HT reuptake inhibition reduces CFS-induced freezing behavior. CFS may be a useful model for detecting the anxiolytic potential of 5-HT reuptake inhibitors.

[DNA strand breaks in epithelial cells from mice with bleomycin induced pulmonary fibrosis]

Bleomycin-induced cytotoxicity is believed to be caused by single- and double-strand DNA breaks. To examine the effect of bleomycin on DNA strand breaks and the role of these breaks in bleomycin induced pulmonary fibrosis in mice, we analyzed DNA strand breaks in situ by TdT-mediated dUTP-biotin nick end labeling (TUNEL), previously described by Gavrieli et al. The nuclei of bronchiolar epithelial cells were strongly stained 1 hr to 12 hr after bleomycin administration, and after that period DNA damage was repaired. Nuclei of alveolar epithelial cells showed positive signals correlated with progression of fibrosis. Although corticosteroids did not block the early DNA damage in bronchiolar epithelial cells, they did inhibit later damage to alveolar epithelial cells and fibrosis. We speculate that the DNA damage in alveolar epithelial cells and the progression of fibrosis in later stages are associated with inflammatory cytokines. These findings show the location and the time course of the DNA damage in bleomycin-induced pneumonitis in mice, and they indicate that the prolongation of DNA damage in alveolar epithelial cells is closely related to fibrinogenesis.

A case of malignant transformation in thoracic vertebral hemangioma following repetitive irradiation and extraction

We report a rare case of thoracic vertebral hemangioma which developed into angiosarcoma during the course of repetitive operations and irradiation. A 44 year old female was operated on for hemangioma of the first thoracic vertebra. The diagnosis of hemangioma was confirmed histopathologically with the specimen from the first operation. The tumor developed multiple lesions later in the clinical course after the first operation, these lesions were removed in four consecutive operations and each histological diagnosis was that of hemangioma. Throughout the period of these operations, the patient was treated with steroid, and with radiotherapy simultaneously. The patient underwent the fifth operation for the recurrence of the tumor on 26 March 1990, and the histopathological diagnosis was not hemangioma but hemangiosarcoma which was considered a malignant transformation. The tumor cells immunohistochemically revealed positive staining with UEA-I, Factor-VIII, as the tumor immunohistochemically showed a vascular endothelioid nature.

Induction therapy with all-trans retinoic acid for acute promyelocytic leukemia: a clinical study of 10 cases, including a fatal [correction of fetal] case with thromboembolism

Ten patients with acute promyelocytic leukemia (APL) were treated with all-trans retinoic acid (ATRA). Eight of 10 patients achieved complete remission (CR), and among the 8 newly diagnosed cases, 7 achieved CR. Five of 8 CR cases remained in CR after 8 to 30 months. Except for hypotension and a large gastric ulcer resulting from hyperhistaminemia, the adverse effects of ATRA were generally mild. Severe thrombotic tendency occurred in a patient treated with ATRA combined with tranexamic acid. Intensive chemotherapy consisting of daunorubicin (DNR) and other agents was scheduled for the patients who achieved CR with ATRA.

[Bacteriological studies of travellar's diarrhoea. 5) Analysis of enteropathogenic bacteria at Osaka Airport Quarantine Station from January 1992 through September 3rd, 1994]

During the last 2 years and 8 months before the closure of Osaka Airport Quarantine Station (from Jan. 1992 to Sep. 3, 1994), a total of 7,421,909 overseas travellers were quarantined. 15,919 reported themselves of suffering from diarrhoea. Bacteriological examination of a total of 6,031 individuals' stools were performed. 1) Various enteropathogenic bacteria were isolated from 31.2% of the stools examined. Isolated species were as follows: Plesiomonas shigelloides, 1,127 cases (59.9%); Vibrio parahaemolyticus, 293 cases (15.6%); Salmonella spp., 262 cases (13.9%); Shigella spp., 235 cases (12.5%); Aeromonas sobria, 93 cases (4.9%); V. cholerae non-O1, 69 cases (3.7%). 2) The enteropathogenic bacteria were isolated through out the year without any seasonal variation. 3) The major regions where the travellers were infected with the pathogens are as follows: V. cholerae non-O1 (NAG Vibrio) and enteropathogenic Escherichia coli, South-East and South-West Asia; Vibrio other than NAG, South-East and East Asia; Shigella, widely distributed but especially in India; P. shigelloides and Salmonella, widely distributed. 4) 2 strains of toxigenic (cholera toxin-producing) V. cholerae O139 were isolated from patients who had visited Indonesia and Thailand, respectively. 5) In 320 cases (17%), plural enteropathogenic bacteria were isolated from single patients, suggesting a high frequency of the mixed infections. 6) Among Shigella strains, S. sonnei were isolated the most, followed by S. flexneri (24.7%), S. boydii (8.8%) and S. dysenteriae (2.9%). 7) Among Salmonella serovers, Salmonella Enteritidis was isolated the most frequently (39 cases, 14.1%). 8) 218 (91.6%) of 238 Shigella strains and 103 (37.6%) of 276 Salmonella strains were resistant to one or more drugs tested (SM.CP.TC.KM.ABPC.NA.OFLX). 9) All of the 22 V. cholerae O1 strains were Ogawa, E1 Tor. Among them, 19 were toxigenic strains and 3 were non-toxigenic. 10) O4:K8 was the most frequently isolated serover of V. paraemolyticus. 87.4% of all V. parahaemolyticus strains were positive with thermostable direct hemolysin (TDH) gene, and 12.6% of them were positive with TDH-related hemolysin (TRH) gene by DNA-probe methods.

Differential expression of gap junction proteins connexin32 and 43 in rat submandibular and sublingual glands

We examined the expression and localization of the gap junction proteins connexin32 and 43 in rat submandibular and sublingual glands. Western blot analysis with anti-connexin32 and 43 antibodies showed bands of approximately 27 KD and 43 KD, respectively, in both glands. Immunofluorescence microscopy demonstrated the presence of reactive spots for connexin32 between acinar cells in both glands. The frequency of connexin32-positive spots in the submandibular glands was approximately equal to that in the sublingual glands. In contrast, reactive spots for connexin43 were observed at the periphery of the alveolar structures in both glands. The connexin43-positive spots in the sublingual glands were more frequent and larger than those in the submandibular glands. No positive spots for both connexins were detected between duct cells in either gland. Immunoelectron microscopy revealed that connexin32 was localized to the gap junctional membranes between acinar cells. Immunolabeling for connexin43 was located on the gap junctions between thin processes of myoepithelial cells. These results suggest that connexin32 of the gap junction is associated with regulation of the secretory function of acinar cells and that connexin43 is associated with that of contraction of the myoepithelial cells in rat salivary glands.

Transesophageal echocardiography in the diagnosis of thoracic saccular aortic aneurysm. The value of transesophageal echocardiography during the course of treatment

Transesophageal echocardiography (TEE) was performed in 17 cases of aortic aneurysms referred to our hospital for further examination and treatment. All 17 cases were treated surgically and TEE was performed as a preoperative examination. In nine of the 17 cases, there were already some signs of bleeding upon admission and in all of these nine cases, rupture of the aneurysm was confirmed during surgery. Measurement on cross-sectional TEE imaging disclosed large aneurysmal diameters in eight of these nine cases, suggesting a close relationship between diameter and rupture. Moreover, observation of the lesions by TEE suggested a relationship between the risk of rupture and morphological characteristics of the thrombus. In seven of the nine bleeding cases, TEE imaging revealed destructive features of the aneurysmal thrombus, such as exfoliation from the aortic wall and/or tearing-off, suggesting expansion of the aortic diameter. Detailed findings of the aneurysm and thrombus on TEE corresponded with surgical findings. Thus, we concluded that TEE is a useful method of obtaining information about aortic aneurysms not only as a preoperative examination but also as an independent examination to determine treatment options and prognosis.

Autonomic hyperreflexia during labour

We present two cases of automatic hyperreflexia (AH) during labour in women with spinal cord damage, in whom AH developed before and after delivery. The AH was successfully controlled using epidural anaesthesia in Case #1, but failed in Case #2. The blood pressure was controlled with nicardipine. However, overdose of nicardipine produces vasodilation and its side effects include headache, flushing and palpitation similar to AH. Considering these effects, we recommend epidural anaesthesia to control AH, because epidural anaesthesia does not only reduce BP, but also blocks the noxious stimuli and relieves the symptoms of AH. Our experience suggests that the epidural catheter can be placed two to three weeks before the date of predicted childbirth, because the onset of labour in a patient with spinal cord damage is difficult to predict and can proceed very rapidly. Also, the epidural catheter is available after the delivery. We recommended the epidural catheter is maintained for 24-48 hr postpartum.

Intermediate TCR cells with self-reactive clones are effector cells which induce syngeneic graft-versus-host disease in mice

It has been established that, even after syngeneic bone marrow transplantation, animals treated with immunosuppressive drugs may suffer from graft-versus-host disease, showing autoimmune-like symptoms. Although the major effector cells are known to be T-cell subsets, detailed characterization of such T cells remains to be investigated. In the present study, we characterized them, especially as to whether they are thymus-derived T cells or extrathymic T cells, and how self-reactive clones were distributed among the above T-cell subsets. BALB/c mice (Mls-1b2a) were irradiated (9 Gy), subjected to bone marrow transplantation, and then treated with cyclosporin A (CsA) for 6 weeks. From 2 weeks after the cessation of CsA, these mice displayed signs of GVH disease. The major target organs included the liver and colon. Two-color staining for CD3 and IL-2R beta was applied to identify CD3-IL-2R beta+ NK cells, CD3-intermediate +IL-2R beta+ cells (i.e., intermediate CD3 or TCR cells of extrathymic origin) and CD3-high+IL-2R beta- cells (i.e., high CD3 cells of thymic origin). It was demonstrated that the major expanding lymphocytes were intermediate TCR cells and that self-reactive clones (V beta 3+ and V beta 11+ cells in this strain of mice) were confined to this population. Interestingly, these self-reactive clones had ability to respond to immobilized anti-V beta 3 and anti-V beta 11 mAbs. Liver MNC in mice with GVH disease which contained the highest proportion of intermediate TCR cells were able to mediate the adoptive transfer of GVH disease to other irradiated (6.5 Gy) mice. Intermediate TCR cells also showed potent cytotoxic activity against syngeneic leukemia cells. These results suggest that intermediate TCR cells are the major effector cells for the induction of syngeneic GVH disease.