[Risk factors and therapeutic methods for sternal wound infection following cardiac surgery]

In a study of 1040 patients undergoing cardiac surgery at The Osaka Medical College Hospital from 1984 through 1991, we analyzed the correlation between a variety of preoperative and operative parameters and the risk of postoperative sternal wound infection, as well as the efficacy of various therapeutic method for this condition. Sternal infection or mediastinitis developed after cardiac surgery in 31 patients (3.0%). As the risk factors for wound infections, age, diabetes mellitus, reexploration, duration of cardiopulmonary bypass and use of bilateral internal thoracic artery grafting were listed. Application of pectoral muscle flaps significantly led to shorten a duration between diagnosis of infection and hospital discharge, and increased survival rate, than the other treating methods such as debridement or irrigation. We conclude that bilateral internal thoracic artery grafts should not be used in the cases with diabetes, and closure with pectoral muscle flaps is effective for sternal infection and mediastinitis.

Effects of late reperfusion on infarct expansion and infarct healing in conscious rats

We examined the effects of late reperfusion on infarct expansion and infarct healing process in conscious rats. Coronary occlusion and reperfusion were carried out in conscious rats 1 week after appropriate surgical preparations. The rats were randomized into the following four groups: sham operated, permanent occlusion, early reperfusion (i.e., reperfusion performed 1 hour after occlusion), and late reperfusion (i.e., reperfusion performed 6 hours after occlusion). Histological examination was performed 7 days after coronary occlusion. In the early reperfusion group, infarct size and expansion were reduced when compared to the permanent occlusion group. In rats subjected to late reperfusion, infarct size and expansion were not different from those in the permanent occlusion group. The extent of unresorbed necrotic myocardium in areas of infarcted scar was reduced in both early and late reperfusion groups. Infiltration by neutrophilic cells into areas of necrotic myocardium 16 hours after myocardial infarction was increased in both reperfusion groups. Infiltration by macrophages 3 days after infarction was also increased in both reperfusion groups. Late reperfusion, therefore, does not affect infarct expansion, but does contribute to the acceleration of the infarct healing process.

Specific cellular immune responses to pancreatic antigen in chronic pancreatitis and Sjögren's syndrome

The specific cellular immune response to the partially purified pancreatic antigen was studied by the peripheral blood lymphocyte proliferation assay in patients with chronic pancreatitis, Sjögren's syndrome, and primary biliary cirrhosis. A significant positive result (stimulation index > 2.0) was observed in 7 of 21 patients with idiopathic chronic pancreatitis (33%; P < 0.05), 6 of 7 patients with Sjögren's syndrome-associated chronic pancreatitis (86%; P < 0.0005), and 6 of 11 patients with Sjögren's syndrome (55%; P < 0.01), compared to normal controls whose stimulation index was 0.94 +/- 0.28 (mean +/- SD; n = 14; range, 0.56-1.60). On the other hand, patients with alcoholic chronic pancreatitis (17%; n = 12), stone-related chronic pancreatitis (0%; n = 7), primary biliary cirrhosis-associated chronic pancreatitis (33%; n = 3), primary biliary cirrhosis (0%; n = 4), systemic lupus erythematosus (17%; n = 6), and autoimmune thyroiditis (0%; n = 6) showed no significant difference from normal controls. Furthermore, in patients with idiopathic chronic pancreatitis who had positive results, a lymphocyte proliferative response to the pancreatic antigen was observed in T cells, especially in the CD4+ T cell subpopulation. These results suggest that the pancreatic antigen plays a role in the pathogenesis of a part of idiopathic chronic pancreatitis and Sjögren's syndrome in association with T cell responses and, also, suggest that autoimmunity may be a possible etiological factor in chronic pancreatitis.

The evaluation of submucosal carcinoma of the esophagus as a more advanced carcinoma

Of 75 patients with superficial esophageal carcinoma, there were 16 cases with epithelial or mucosal, and 59 cases with submucosal, lesions. The incidence of nodal metastasis in patients with epithelial or mucosal carcinoma was zero, and the 5-year survival rate was 100%. However, 13 out of 59 cases (22.0%) with submucosal carcinoma were accompanied by nodal involvement, and the rate of vessel invasion was 27.1% (16/59). Even in 46 cases of submucosal carcinoma without nodal involvement, there were 13 cases (22.1%) with vessel invasion. The 5-year survival rate of the 26 submucosal cases with either nodal metastasis or vessel invasion was 37.6%, and even that of the 33 cases with neither lymph node metastasis nor vessel invasion was 60.0%. On the other hand, of the 74 patients with carcinoma invading the muscularis propria, there were 35 cases (47.3%) without nodal metastasis and 27 cases (36.5%) which were also free of vessel invasion. The 5-year survival rate of the former was 32.6%, and of the latter 33.1%. On the basis of these findings, we wish to emphasize that submucosal carcinoma should be classified as an advanced carcinoma.

Characterization of an eosinophilic leukemia cell differentiation factor (ELDF) produced by a human T cell leukemia cell line, HIL-3

An adult T cell leukemia cell line, HIL-3, constitutively secretes a factor which induces the phenotypical and functional eosinophilic differentiation of a human eosinophilic leukemia cell line, EoL-1. Biochemical characteristics of the factor, termed eosinophilic leukemia cell differentiation factor (ELDF), were examined. ELDF was precipitated by 35 to 65% saturated ammonium sulfate from the culture supernatants of HIL-3 cells (HIL-3 sup). ELDF was eluted in a peak corresponding to a molecular weight of 30 to 40 kd by gel filtration. Isoelectric focusing in the Rotofor showed that ELDF had isoelectric points of 5 to 6. ELDF was trypsin-sensitive and stable to heat treatment at 65 degrees C for 30 minutes but labile at 80 degrees C or pH lower than 3. Half of the activity adhered to lentil-lectin but not to Con-A, indicating that a part of ELDF is glycoprotein with an N-linked carbohydrate moiety, which did not seem to be essential for ELDF activity. The biochemical characteristics of ELDF and blocking experiments using cytokine-specific neutralizing antibodies suggest that ELDF is different from gamma-interferon (IFN-gamma), tumor necrosis factor-alpha (TNF-alpha), granulocyte-macrophage colony-stimulating factor (GM-CSF), interleukin-5 (IL-5) and interleukin-2 (IL-2), which may exist in HIL-3 sup, and that ELDF may be a previously unrecognized leukemia differentiation factor.

DNA ploidy as a prognostic factor in early esophageal carcinoma

Cell nuclear DNA content was cytophotometrically determined in biopsy specimens obtained from thirty-five patients with superficial esophageal carcinoma. The relationship between the DNA distribution pattern and histopathological features, prognosis and postoperative survival time was then investigated. Patients with a low ploidy pattern had a more favorable postoperative course, with 62% attaining a 5-year survival rate, than those with high ploidy, of whom 34% attained a 5-year survival rate (p < 0.01). The recurrence rate was higher for the high ploidy pattern (64.3%) than for the low ploidy pattern (35.3%). Moreover, the rate of recurrence within 2 years was 50% in high ploidy, which was higher than the 5.9% rate in the case of low ploidy (p < 0.05). Although there was no clearly established relationship between the DNA distribution pattern and clinicopathological features, a multivariate analysis revealed that the DNA distribution pattern was one of the independent and significant prognostic factors of superficial esophageal carcinoma. These results thus suggest the usefulness of a preoperative DNA analysis of biopsy specimens in predicting the prognosis and determining perioperative therapeutic strategy for both superficial esophageal carcinoma and for advanced cases.

Intracellular transport, organelle biogenesis and establishment of Golgi identity: impact of brefeldin A on the activity of lipid synthesizing enzymes

1. The effect of brefeldin A (BFA) on generation of transport vesicles, synthesis of phosphoglycerides, sphingosine and ceramides, and utilization of the sphingolipid precursors in the formation of sphingomyelin and glycosphingolipids in Golgi was investigated. 2. In the presence of 5-10 micrograms/ml BFA, the incorporation of [3H]palmitate into glycerides, phosphoglycerides and sphingolipids decreased 45-60%, and the production of endoplasmic reticulum transport vesicles was reduced 30-50%. 3. In Golgi membranes, the presence of 5-10 micrograms/ml BFA in the mixture, assembled to generate Golgi vesicles, evoked inhibitory effect on the synthesis of sphingomyelin, glycosphingolipids and phosphatidylcholine. On average, the synthesis of the sphingolipids and phosphatidylcholine and production of Golgi transport vesicles declined to 30-40%. 4. Addition of 5-10 micrograms/ml BFA to the assay mixture prepared to measure the activity of cytidylyltransferase, phosphocholine diacylglyceroltransferase, and serine palmitoyltransferase, caused up to 50% inhibition of the enzymes involved in the synthesis of phosphatidylcholine and up to 70% inhibition of the enzyme generating 3-ketosphinganine. 5. The results suggest that BFA inhibits the synthesis of phosphoglycerides and sphingolipids. This, at first, is displayed in reduced production of endoplasmic reticulum and Golgi transport vesicles, while the depletion of sphingolipids abrogates the identity of Golgi membranes.

The activities of coenzyme Q10 and vitamin B6 for immune responses

Coenzyme Q10 (CoQ10) and vitamin B6 (pyridoxine) have been administered together and separately to three groups of human subjects. The blood levels of CoQ10 increased (p < 0.001) when CoQ10 and pyridoxine were administered together and when CoQ10 was given alone. The blood levels of IgG increased when CoQ10 and pyridoxine were administered together (p < 0.01) and when CoQ10 was administered alone (p < 0.05). The blood levels of T4-lymphocytes increased when CoQ10 and pyridoxine were administered together (p < 0.01) and separately (p < 0.001). The ratio of T4/T8 lymphocytes increased when CoQ10 and pyridoxine were administered together (p < 0.001) and separately (p < 0.05). These increases in IgG and T4-lymphocytes with CoQ10 and vitamin B6 are clinically important for trials on AIDS, other infectious diseases, and on cancer.

[Studies on onset patterns in antithyroid drug-induced agranulocytosis]

We studied the patterns of the onset of antithyroid drug-induced agranulocytosis. From 1975 to 1990, 19,050 patients with Graves' disease receiving treatment with antithyroid drugs were seen at our clinic. For all patients with Graves' disease treated with an antithyroid drug, a routine white blood cell count was done every 2 weeks until euthyroid state was gained, and a count was done once every moth thereafter. Of these, 70 were found to have agranulocytosis. Agranulocytosis was defined as a granulocyte count of 500/mm3 or less. In only 19 of the 70 was agranulocytosis detected after the occurrence of infection (symptomatic: classical agranulocytosis). The remaining 51 patients were asymptomatic when agranulocytosis was detected during routine white blood cell and granulocyte count monitoring. However, 17 of the 51 patients became symptomatic several days after the withdrawal of antithyroid drug treatment (shifted from asymptomatic to symptomatic agranulocytosis). Thirty-four patients had no symptoms of infection throughout the course of the disease (asymptomatic agranulocytosis). In conclusion, 1) We found three patterns in the onset of antithyroid drug-induced agranulocytosis: classical (symptomatic), a shift from asymptomatic to symptomatic, and asymptomatic agranulocytosis, 2) Unexpectedly, classical (symptomatic) agranulocytosis was seen in only 19 of the 70 patients, 3) We were again remained of the importance of routine white blood cell and granulocyte count monitoring.

Hereditary spherocytosis with congestive heart failure: report of a case

We report herein a case of 62-year-old woman with hereditary spherocytosis (HS) and congestive heart failure (CHF). Although her history revealed jaundice in the early neonatal period, she had never undergone a physical examination and thus, the diagnosis of HS and CHF was not made until the age of 61 when she complained of dyspnea and palpitations on exertion. The CHF was subsequently found to be related to severe anemia in the presence of underlying heart disease. Splenectomy was performed in an attempt to relieve the severe hemolytic process. Following this, all the symptoms improved without the need for any cardiovascular drugs and she has been well throughout the 34 months follow up.

Survival of cancer patients on therapy with coenzyme Q10

Over ca. 25 years, assays in animal models established the hematopoietic activities of coenzyme Q's in rhesus monkeys, rabbits, poultry, and children having kwashiorkor. Surprisingly, a virus was found to cause a deficiency of CoQ9. Patients with AIDS showed a-"striking"-clinical response to therapy with CoQ10. The macrophage potentiating activity of CoQ10 was recorded by the carbon clearance method. CoQ10 significantly increased the levels of IgG in patients. Eight new case histories of cancer patients plus two reported cases support the statement that therapy of cancer patients with CoQ10, which has no significant side effect, has allowed survival on an exploratory basis for periods of 5-15 years. These results now justify systematic protocols.

DNA packaging ATPase of bacteriophage T3

A defined in vitro DNA packaging system of phage T3, which is composed of purified proheads and two packaging proteins, the products of genes 18 and 19 (gp18 and gp19, respectively), displayed a DNA-dependent ATPase activity. ATP was hydrolyzed to ADP and Pi. The ATPase activity was stimulated by nonpackageable DNA, such as single-stranded or circular DNA, or RNA (nonpac-ATPase). Among the inhibitors of DNA packaging, actinomycin D specifically inhibited the ATPase activity that was tightly coupled to DNA packaging (pac-ATPase), but did not inhibit the nonpac-ATPase activity. Both activities depended upon a functional packaging complex, but the nonpac-ATPase, once activated, did not require DNA. Unpackageable pUC18 DNA inhibited the pac-ATPase and the phage yield in parallel. Approximately one molecule of ATP was hydrolyzed during the translocation of 1.8 bp of T3 DNA.

Sandwich enzyme immunoassay for rat retinol-binding protein using antibody against recombinant antigen and its application

The development of a sandwich enzyme immunoassay for rat retinol-binding protein using molecular biological techniques was described. Rat retinol-binding protein gene cloned by the PCR method was expressed by a fusion vector pEZZ18 in Escherichia coli strain HB101. A recombinant retinol-binding protein fused with IgG-binding domain ZZ of protein A was purified with IgG-Sepharose. Antibody against the recombinant protein was found to be specific to rat retinol-binding protein in plasma by immunoblot analysis. Affinity-purified anti-recombinant protein IgG was biotinylated and used for the sandwich enzyme immunoassay. In this assay, the measurable range is 1.9-60 ng/ml and the coefficients of variation within and between the assay series (assay range: 4-30 ng/ml) are 4.30 +/- 4.33 and 5.32 +/- 1.45%, respectively. Cross-reactivity of the immunoassay was examined using bovine, human, and mouse serum. There was a cross-reaction only with mouse serum. In an in vitro experiment, retinol-binding protein produced by rat hepatocytes could be measured by the sandwich enzyme immunoassay.

[UV-microspectrophotometric and flow cytometric analysis of the same samples using DAPI/HP staining]

A simple one-step double staining with DAPI and hematoporphyrin (HP) was used for UV-microspectrophotometric (UV-MSPM) and flow cytometry (FCM) analysis of the same samples. The specimens analyzed included fresh biopsy and/or surgical materials, trimmed 50 microns-thick paraffin sections and smears (with the latter not available for FCM). We provided the special technology for preserving the cytoplasm as far as possible to permit measurement of cell size and N/C ratio. DAPI indicates DNA content under 365 nm and HP of total protein content under 670 nm UV-MSPM. The DAPI can measure the nuclear size and the latter the cell size. DAPI/HP staining yielded much more accurate measurements than staining with FITC and PI. The use of both MSPM and FCM with cell sorting on the same samples is very helpful in cytology and histopathology for evaluating and differentiating borderline lesions and grade of malignancy, as well as oncostatic effectivity. Our goal is to combine this technology with the automated cytologic screening system CYBEST, which was developed by Tanaka et al, based on a morphometric device.

A new method to determine the level of coenzyme Q10 in one drop of human blood for biomedical research

This method has been designed to determine the levels of CoQ10 in human blood which utilizes only one drop of blood (0.05 ml). This method encourages and facilitates more frequent monitoring of blood levels of CoQ10, and of clinical importance, reveals the presence or absence of compliance. CoQ11 was used as an internal standard. The mean recovery of CoQ10 was 96%. The correlation coefficient between using 1.0 ml and 0.1 ml of blood and between using 1.0 and 0.05 ml was 0.997 in the two comparisons. Therefore, it can be accurate to monitor the level of CoQ10 in a -"finger-prick"-drop of blood, and at least 24 such determinations can be conducted in a 2-day period.

Construction of sandwich enzyme immunoassay for rat transthyretin using recombinant antigen approach, and its application

A sandwich enzyme immunoassay for rat transthyretin using a recombinant antigen approach is described. Rat transthyretin cDNA was cloned by PCR. Rat transthyretin fused with the IgG-binding ZZ domain of protein A was expressed in E. coli using the fusion vector pEZZ18. Antibody against the fusion protein was specific to rat transthyretin in plasma as shown by immunoblotting. Affinity-purified anti-rat transthyretin-ZZ was biotinylated and used for the sandwich enzyme immunoassay. In this assay, the measurable range was 1.2-50 ng/ml and the coefficients of variation within and between the assay series (assay range: 2.5-20 ng/ml) were 1.31 +/- 0.08% and 3.50 +/- 1.46%, respectively. Cross-reactivity was examined using bovine, human, and mouse serum. There was a cross-reaction only with mouse transthyretin. In an in vitro experiment, transthyretin secreted by rat hepatocytes could be measured by the sandwich enzyme immunoassay.

[Review: recent studies on a human eosinophilic leukemia cell line, EoL as an experimental model of eosinophils]

Recently, a human eosinophilic leukemia cell line, EoL was established from an eosinophilic leukemia patient. EoL-1 cells have the cytohistologic features of myeloblasts under normal culture conditions, and they can be induced to differentiate into eosinophilic granule-containing cells but not into other lineage cells under several culture conditions and are therefore considered to be committed precursors of eosinophils. Furthermore, EoL-1 cells can also be induced to differentiate functionally to show PAF-induced Ca2+ influx and actin polymerization. On the other hand, EoL-3 cells show constitutive expression of Fc epsilon RII, Fc gamma RII, LFA-1 and ICAM-1 on their cell surface. The EoL cells may provide new information on some aspects of the signal transduction mechanisms involved in the proliferation, differentiation and activation of eosinophils.

Cytophotometric DNA content and argyrophilic nucleolar organiser regions of oesophageal carcinoma

The cytophotometric DNA content and the argyrophilic nucleolar organiser regions (AgNORs) of biopsy specimens taken before undergoing any treatment were examined in 91 surgically treated oesophageal carcinoma cases. There was a significant linear dependence between the mean DNA content and the number of AgNOR per nucleus (AgNOR number) (r = 0.615, P < 0.001). The DNA distribution pattern and the range of the AgNOR number also showed a significant correlation (P < 0.01). Twenty three of 28 cases with a low AgNOR number (< 4) were then determined to have a diploid pattern (type II), while 17 out of 22 cases with a high AgNOR number (> or = 6) had high ploidy values (type IV). The patients with a type II DNA distribution pattern and a low AgNOR number thus showed a good post-operative course with a 5 year survival rate of 55.2%, whereas no patients survived over 4 years among the 17 cases with both a type IV DNA pattern and a high AgNOR number (P < 0.001). These data thus demonstrate the close relationship between cytophotometric DNA content and AgNOR number and suggest that the combined detection of these two parameters, using biopsy specimens, should be of benefit in making an accurate preoperative evaluation of prognosis for patients with oesophageal carcinoma.

[Effects of nipradilol on the patients of angina pectoris: results from the study of the exercise electrocardiography using HR-ST loop method]

This study was performed to confirm the usefulness of 12 mg nipradilol, a beta-blocker with a vasodilator action similar to that of nitrate-type drugs, in the treatment of effort angina pectoris. It also discusses the mechanism of the action of this drug when using the exercise test heart rate-ST displacement analysis. The symptom threshold multistage graded exercise test was performed using nine patients with chronic stabilized effort angina pectoris after an observation period and an 8-week administration period and HR-ST analysis was performed simultaneously. The number of anginal attacks significantly decreased from the 2nd week, and the heart rate at rest decreased significantly in the prone position although blood pressure did not change. The maximum oxygen intake increased markedly from 13.7 +/- 1.1 ml/kg/min to 19.3 +/- 2.5 ml/kg/min, and the maximum ST decrease improved significantly from 1.72 +/- 0.45 mm to 1.17 +/- 0.19mm. In HR-ST analysis, delta ST/delta HR and delta ST/delta DP tended to improve slightly. Since monotherapy with a beta-blocker causes significant increase in delta ST/delta HR and delta ST/delta DP, it was assumed that a vasodilator action in addition to a beta-blocker action is involved in the improvement of maximum ST decrease brought about by nipradilol.

Glycosulfatase activity of Helicobacter pylori towards gastric sulfomucin: effect of nitecapone

A glycosulfatase activity towards human gastric sulfomucin was identified in the extracellular material elaborated by H. pylori, a pathogen implicated in the etiology of gastric disease. The purified enzyme exhibited maximum activity at pH 5.7 in the presence of 0.3% Triton X-100 and 100mM CaCl2, and displayed on SDS-PAGE an apparent molecular weight of 30kDa. The H. pylori glycosulfatase effectively caused desulfation of N-acetylglucosamine-6-sulfate and galactose-6-sulfate of the carbohydrate chains of mucins, as well as that of glucose-6-sulfate of glyceroglucolipids, but was ineffective towards galactosyl -and lactosylceramide sulfates which contain galactose-3-sulfate. The glycosulfatase activity towards human gastric sulfomucin was inhibited by an antiulcer agent, nitecapone, which at its optimal concentration (100 micrograms/ml) caused a 61% decrease in mucin desulfation. The results show that H. pylori through its glycosulfatase activity causes desulfation of sulfated mucins and glyceroglucolipids of the protective mucus layer, and that nitecapone is able to interfere with this detrimental action.

Granulocyte colony-stimulating factor treatment of antithyroid drug-induced granulocytopenia

The primary objective of this study was to ascertain the effectiveness of granulocyte colony-stimulating factor in the treatment of antithyroid drug-induced granulocytopenia of varying degree. Sixteen patients with Graves' disease with antithyroid drug-induced granulocytopenia (granulocyte counts < 1.0 x 10(9)/L) each received a daily dose of 75 micrograms of granulocyte colony-stimulating factor administered subcutaneously. Within 24 hours of the first injection, the granulocyte count increased (0.6 to 12.3 x 10(9)/L) in all 10 patients with mild granulocytopenia (granulocyte counts between 0.5 and 1.0 x 10(9)/L) and all three with moderate granulocytopenia (granulocyte counts < 0.5 x 10(9)/L). The three remaining patients with severe granulocytopenia (agranulocytic), whose granulocyte counts were zero, did not recover from granulocytopenia until the 6th, 7th, and 14th days of treatment with granulocyte colony-stimulating factor. Examination of bone marrow taken at the onset of the disease in all three agranulocytic patients showed a prominent decrease in granulocytic series, while identical examination in six of eight patients with mild to moderate granulocytopenia showed close to normal granulocytic series. There was no elevation of serum granulocyte colony-stimulating factor concentration in four patients with mild granulocytopenia and one with moderate granulocytopenia at the onset of their disease, whereas those of the remaining three patients with severe granulocytopenia (agranulocytic) increased at onset of agranulocytosis. This information led us to conclude that: (1) granulocyte colony-stimulating factor is effective in the treatment of antithyroid drug-induced mild to moderate granulocytopenia and (2) in severe agranulocytic cases, granulocyte colony-stimulating factor is not effective. Accordingly, we were again reminded of the importance of early diagnosis and treatment of antithyroid drug-induced agranulocytosis.

Mutagenic activity of some platinum and palladium complexes

The mutagenic properties of 16 platinum compounds were studied using Salmonella typhimurium TA98 and TA100. Eight of the compounds were considered direct mutagens, as their mutagenicity was not dependent on metabolic activation by liver extracts. Potent mutagenicity and high toxicity were exhibited by cis-Pt(NH3)2Br2, cis-Pt(NH3)2Cl2, Pt(C5H12N2)Cl2 and Pt(en)Cl2 for both bacterial strains. When distilled water was used as the carrier solvent, these compounds were strongly mutagenic and toxic, but much less so when dimethyl sulfoxide was the solvent.

Major histocompatibility antigen-restricted cytotoxicity in inflammatory bowel disease

BACKGROUND

The role of cytotoxicity mediated by peripheral blood mononuclear cells for colonic epithelial cells in inflammatory bowel disease (IBD) is still controversial. To clarify it, we studied major histocompatibility antigen (MHC)-restricted T cell-mediated cytotoxicity (CTL).

METHODS

Cytotoxicity was measured by 51Cr release from colonic cells after the 6-hour incubation with peripheral blood mononuclear cells in 11 IBD patients (6 with Crohn's disease and 5 with ulcerative colitis).

RESULTS

CTL activity (E/T ratio = 200:1 or 100:1) for autologous target cells was significantly increased (22%-40%) in 5 of 6 CD and 4 of 5 UC patients (22%-64%) compared with that for allogeneic target cells. The increase in CTL activity was mainly inhibited by anti-MHC class I and CD8 monoclonal antibodies (50 micrograms/mL), while it was partially inhibited by anti-MHC class II or CD4 antibodies in some patients. Complement-mediated depletion of CD2+ cells also significantly decreased CTL activity.

CONCLUSIONS

The results indicate that MHC-restricted T cell cytotoxicity may play a role in mucosal damage in some patients of IBD.