Computerized color-vision test based upon postreceptoral channel sensitivities.

An automated, computerized color-vision test was designed to diagnose congenital red-green color-vision defects. The observer viewed a yellow appearing CRT screen. The principle was to measure increment thresholds for three different chromaticities, the background yellow, a red, and a green chromaticity. Spatial and temporal parameters were chosen to favor parvocellular pathway mediation of thresholds. Thresholds for the three test stimuli were estimated by four-alternative forced-choice (4AFC), randomly interleaved staircases. Four 1.5-deg, 4.2 cd/m2 square pedestals were arranged as a 2 x 2 matrix around the center of the display with 15-minute separations. A trial incremented all four squares by 1.0 cd/m2 for 133 ms. One randomly chosen square included an extra increment of a test chromaticity. The observer identified the different appearing square using the cursor. Administration time was approximately 5 minutes. Normal trichromats showed clear Sloan notch as defined by log (deltaY/deltaR), whereas red-green color defectives generally showed little or no Sloan notch, indicating that their thresholds were mediated by their luminance system, not by the chromatic system. Data from 107 normal trichromats showed a mean Sloan notch of 0.654 (SD = 0.123). Among 16 color-vision defectives tested (2 protanopes, 1 protanomal, 6 deuteranopes, & 7 deuteranomals), the Sloan notch was between -0.062 and 0.353 for deutans and was < -0.10 for protans. A sufficient number of color-defective observers have not yet been tested to determine whether the test can reliably discriminate between protans and deutans. Nevertheless, the current data show that the test can work as a quick diagnostic procedure (functional trichromatism or dichromatism) of red-green color-vision defect.

Locoregional immunotherapy of malignant effusion from colorectal cancer using the streptococcal preparation OK-432 plus interleukin-2: induction of autologous tumor-reactive CD4+ Th1 killer lymphocytes.

In total, 16 patients with cytologically proven malignant effusion from colorectal cancer were treated by locoregional administration of the streptococcal preparation OK-432 alone or OK-432 plus the T-cell growth factor interleukin (IL)-2, and the action mechanism of the treatment was studied. A positive clinical response, showing a cytologic disappearance of cancer cells and decrease of effusion, was observed in nine of 11 (82%) patients treated with OK-432 alone and in all five patients treated with OK-432 plus IL-2. Flow cytometric analysis revealed that OK-432 plus IL-2 locally induced acute inflammation-like responses, including serial cellular infiltrations of granulocyte migration within a matter of hours, and activation of macrophages and T lymphocyte involvement within the following days, and that a predominant expansion of CD3+CD4+ lymphocytes (CD: cluster of differentiation) was induced by in vitro stimulation with IL-2 of locoregional cells after the OK-432 administration (OK/IL-2AK cells). The OK/IL-2AK cells produced tumour necrosis factor-alpha and interferon-gamma, but these cells did not produce IL-4 and IL-6. The OK/IL-2AK cells expressed potent killing activity against autologous tumour cells. This activity was abrogated by treatment of the lymphocytes with anti-CD3, -CD4, -TCRalphabeta antibody, and by the treatment of target cells with anti-human leukocyte antigen (HLA)-DR antibody. The OK/IL-2AK cells expressed Fas-L gene, and flow cytometric analysis demonstrated HLA-DR expression in approximately 75% of CEA+ or cytokeratin+ effusion cells. TCRVbeta gene analysis of the OK/IL-2AK cells showed an oligoclonal usage of TCRbeta20, which was also involved in the cytotoxic mechanism of the OK/IL-2AK cells. Single-strand conformational polymorphism analysis demonstrated the clonotypes for the TCRVbeta20 gene, and the CDR3s of the gene were sequenced. The clonotypic PCR using the TCRVbeta20-CDR3 sequences could detect the CDR3-identical TCRs in effusion lymphocytes from the other patients. Taken together, it is suggested that locoregional administration of OK-432 plus IL-2 is highly effective for the management of malignant effusion from colorectal cancer. OK-432 plus IL-2 induces autologous tumour-reactive CD4+ Th1 killer lymphocytes, which recognise tumour antigen(s) presented with HLA class II molecules on effusion tumour cells by means of preferential usage of TCRVbeta20. The clonotypic PCR using the TCRVbeta20-CDR3 sequences may be informative for treating malignant effusion from colorectal cancer using OK-432 plus IL-2.

Intracavitary chemotherapy with 5-fluoro-2'-deoxyuridine (FdUrd) in malignant brain tumors.

BACKGROUND: After completing basic research on the anti-tumor effects and neurotoxicity of 5-fluoro-2'-deoxyuridine (FdUrd) and the balance of thymidine kinase and thymidine phosphorylase activities and confirming the safety of intrathecal FdUrd administration in a previous clinical study of meningeal carcinomatosis, intracavitary administration of FdUrd was performed as a second trial in patients with malignant glioma and metastatic brain tumors. METHODS: The study population consisted of 13 patients, six with glioblastoma, one with anaplastic astrocytoma and six with metastatic brain tumors. This treatment was applied for cystic, small-volume residual or recurrent tumors. FdUrd (1-10 microg) was administered every day at least 25 times through an Ommaya device placed in the cyst or closed postoperative cavity reconstructed with a patch of galea aponeurotica. Intracavitary chemotherapy with FdUrd was preceded by radiation therapy in two patients but no other adjuvant therapy was performed. RESULTS: No side effects such as headache, nuchal pain, convulsive attack, bone marrow suppression or liver dysfunction were observed during the course of chemotherapy. Seven of the 13 patients showed responses: complete response six, minor response one, no change two and progressive disease four after the twenty-fifth intracavitary administration of FdUrd when tumor sizes on CT scans and MRI before and after intracavitary chemotherapy were compared. CONCLUSIONS: Intracavitary FdUrd chemotherapy may be useful for the treatment of small-volume tumors.

[A case of inoperable advanced gall bladder cancer responding to intra-arterial infusion of 5-fluorouracil (5-FU) and leucovorin (LV)].

The prognosis in cases of inoperable advanced gall bladder cancer is poor. We report here a case of inoperable advanced gall bladder cancer that responded to treatment with continuous intra-arterial infusion of 5-FU and bolus injection of LV for biochemical modulation. The patient was an 81-year-old woman, who visited a nearby clinic with the chief complaints of general fatigue and right lateral abdominal pain. A mass lesion which occupied from the dorsal surface of the liver to the pancreatic head was found by ultrasonography, and she was referred to our hospital for further diagnosis and therapy. The diagnosis was advanced gall bladder cancer of Stage IVa (S2, N3, P0, H0, Hinf1, Dinf1). For the selective arterial infusion of anticancer drugs, the patient underwent intra-arterial cannulation into the common hepatic artery, with a connecting subcutaneous port for arterial infusion therapy. The treatment schedule for 5-FU and LV therapy consisted of continuous infusion of 5-FU of 333 mg/m2 for 72 hr and bolus injection of LV of 20 mg/m2 3 times at 24 hr intervals. This treatment was repeated every 2 weeks. No side effects were observed after the first administration during hospitalization, so the treatment was continued up to 17 times on an outpatient basis. A tumor response was seen in the primary lesion, No. 8 and No. 16 lymph node metastases. A partial response was observed for 13 months and the overall survival was 15 months. These findings may imply that treatment with intra-arterial infusion of 5-FU and LV can be an effective chemotherapy for prolongation of survival in patients with inoperable advanced gall bladder cancer.

The consequences of opponent rectification: the effect of surround size and luminance on color appearance.

Smith and Pokorny (Vision Res. 36 (1996) 3087.) described conditions under which chromatic contrast induction can reveal a hiatus, a region of chromaticity space which appears neither reddish nor greenish when presented in a chromatic equiluminant surround. The current study investigated the effect of varying the size and the luminance of the inducing surround. The color appearance of test stimuli in chromatic surrounds was assessed by asymmetric color matching to a comparison display. Equiluminant (12 cd/m(2)), 1 degrees square stimuli were generated on a CRT display and presented haploscopically. Ten test fields varied in their L-cone excitation along a constant S-cone line. The chromatic surrounds were of either high (red) or low (green) L-cone excitation on a constant S-cone line. In Experiment 1, surrounds were 1.1 degrees, 1.5 degrees, 2.0 degrees, or 3.0 degrees square (surround widths of 3', 15', 30', 1 degrees ). In Experiment 2, the test and comparison surrounds were at higher (16.7 cd/m(2)) or lower (8.3 cd/m(2)) retinal illuminance than the test field. Contrast induction reached an asymptote for surround widths of 30' or larger. The amount of induction decreased for the surround widths of 15' and 3'. The hiatus was present for the larger surrounds and decreased as surround size decreased. The use of a higher or lower surround luminance did not affect the magnitude of induction or the size of the hiatus.

[Locoregional immunotherapy of malignant effusions for colorectal cancer using OK-432 and its acting mechanisms--possibility of molecular diagnosis using TCRCDR 3 sequence].

Locoregional administration using OK-432 was evaluated in treating malignant effusion. Positive clinical responses were seen in 19 (52%) of 36 gastric cancer patients, and in 9 (90%) of 10 colon cancer patients (p < 0.05), indicating its clinical benefit in treating malignant effusion of colon cancer. Fever elevation was observed in 43 (93%) patients and local pain occurred with 9 (20%) of 46 administrations. Immunological analysis for responder patients with rectal cancer revealed that OK-432 induced autologous tumor-reactive CD 3+ CD 4+ TCRV beta 20+ killer lymphocytes. The TCR gene analysis permitted us to clone a V beta 20 CDR 3 sequence, by which positive bands were shown in 3 (75%) of 4 responders and negative bands in 3 (100%) of 3 non-responders. It is suggested that cross-antigenicity exists between OK-432 and colon cancer, and that genetic analysis using the TCRCDR 3 sequence makes it possible to predict responder patients to OK-432 immunotherapy.

Variations in normal color vision. I. Cone-opponent axes.

Early postreceptoral color vision is thought to be organized in terms of two principal axes corresponding to opposing L- and M-cone signals (LvsM) or to S-cone signals opposed by a combination of L- and M-cone signals (SvsLM). These cone-opponent axes are now widely used in studies of color vision, but in most cases the corresponding stimulus variations are defined only theoretically, based on a standard observer. We examined the range and implications of interobserver variations in the cone-opponent axes. We used chromatic adaptation to empirically define the LvsM and SvsLM axes and used both thresholds and color contrast adaptation to determine sensitivity to the axes. We also examined the axis variations implied by individual differences in the color matching data of Stiles and Burch [Opt. Acta 6, 1 (1959)]. The axes estimated for individuals can differ measurably from the nominal standard-observer axes and can influence the interpretation of postreceptoral color organization (e.g., regarding interactions between the two axes). Thus, like luminance sensitivity, individual differences in chromatic sensitivity may be important to consider in studies of the cone-opponent axes.

Variations in normal color vision. II. Unique hues.

We examined individual differences in the color appearance of nonspectral lights and asked how they might be related to individual differences in sensitivity to chromatic stimuli. Observers set unique hues for moderately saturated equiluminant stimuli by varying their hue angle within a plane defined by the LvsM and SvsLM cone-opponent axes that are thought to characterize early postreceptoral color coding. Unique red settings were close to the +L pole of the LvsM axis, while green, blue, and yellow settings clustered along directions intermediate to the LvsM and SvsLM axes and thus corresponded to particular ratios of LvsM to SvsLM activity. Interobserver differences in the unique hues were substantial. However, no relationship was found between hue settings and relative sensitivity to the LvsM and SvsLM axes. Moreover, interobserver variations in different unique hues were uncorrelated and were thus inconsistent with a common underlying factor such as relative sensitivity or changes in the spectral sensitivities of the cones. Thus for the moderately saturated lights we tested, the unique hues appear largely unconstrained by normal individual differences in the cone-opponent axes. In turn, this suggests that the perceived hue for these stimuli does not depend on fixed (common) physiological weightings of the cone-opponent axes or on fixed (common) color signals in the environment.

Manometric and hormonal changes after distal partial gastrectomy.

BACKGROUND: Alkaline oesophagitis attributable to duodenal mechanisms may induce oesophageal carcinogenesis in a rat reflux model. AIM: To investigate the mechanism of the regurgitation after distal partial gastrectomy. METHODS: Oesophageal manometry was used in 16 patients before and after distal partial gastrectomy with reconstruction by Bilroth methods. Serum concentrations of four gastrointestinal hormones were measured by radioimmunoassay in 10 gastrectomy patients and nine healthy volunteers before and after a standardized meal. RESULTS: The lower oesophageal sphincter pressure was reduced to 83% after surgery. The amplitude and duration of the peristaltic waves tended to be increased, and the velocity tended to be less after surgery (amplitude 120%, duration 114%, velocity 88%). Interrupted waves appeared more frequently after surgery. The manometric changes in gastrectomized patients are considered to be disadvantageous relative to regurgitation. After surgery, gastrin and pancreatic polypeptide were completely abolished postprandially, whereas cholecystokinin and neurotensin were significantly increased. CONCLUSION: The hormonal changes should have a suppressive effect on the lower oesophageal sphincter. Both the manometric and the hormonal changes may exacerbate reflux oesophagitis after distal partial gastrectomy.

T-cell receptor V beta gene usage of human cytotoxic T-cell clones obtained from gastric cancer patients.

Nine T-cell clones have been established from tumor-infiltrating lymphocytes (TIL) isolated from ascitic fluid of a gastric cancer patient. Five of them retained cytotoxicity against autologous tumor cells (AuTu), and were all CD4+. Each clone had different usage of T-cell receptor (TCR) V beta gene as assessed by Southern blot analysis. Using AuTu and two allogeneic gastric cancer cell lines as targets, we selected three clones with unique cytotoxic properties. Two of these clones (Clone 1 and 2) preferentially lysed AuTu, but showed no or marginal cytotoxicity against allogeneic gastric cancer cells, and one clone (Clone 7) showed appreciable cytotoxicity against AuTu and allogeneic gastric cancer cells. In the detailed analysis of TCRV beta gene usage, Clone 1, 2, and 7 expressed V beta 13.1/D beta 1/J beta 1.5/C beta 1, V beta 3/D beta 2/J beta 2.4/C beta 2, and V beta 9/D beta 1/J beta 1.4/C beta 1, respectively, and the primary structures of the three TCRVb genes did not share any common features, neither in the sizes of their complementarity determining region 3 (CDR3) nor in their amino acid compositions. Interestingly, PBL of the same patient expressed CDR3 identical to that of Clone 2 and 7, but not that of Clone 1. CDR3 identical to that of Clone 2 and 7 were also detected in TIL of other gastric cancer patients. These results show that some AuTu-specific CTL included in TIL are circulating in peripheral blood, and that the CDR3 identical to that of the CTL is expressed extensively in TIL among different gastric cancer patients. Screening of the expression of the CDR3 in other gastric cancer patients is recommended to develop an immuno-therapy of gastric cancer based on antigenic peptide.

[Usefulness of percutaneous low output microwave tissue coagulation therapy for solitary liver cancer].

The possible use of percutaneous transhepatic low output microwave tissue coagulation therapy (PMCT) using ultra-sonography under local anesthesia for solitary liver cancer was studied. The subjects were 13 patients having primary or metastatic liver cancer with solitary liver tumor less than 3 cm in diameter, including 7 hepatocellular carcinomas and 6 metastatic liver cancers. PMCT was performed continuously 3 times at an output of 30 watts for 30 seconds at a time. Tumors less than 3 cm in diameter were completely coagulated by irradiation from 2 to 6 times, judging by enhanced CT. No tumor recurrence was recognized in the coagulation area. However, in two cases of metastasis from pancreatic carcinoma, multiple metastases were found at another site in the liver by 2 months after PMCT. Thus, the results suggest that PMCT is a useful therapy for small liver tumor as a local control.

Telomerase activity and alterations in telomere length in human brain tumors.

Telomerase activity was examined in 170 human brain tumor tissues, and terminal restriction fragment (TRF) length was examined in 152 of the 170. Telomerase activity was detected in 61.7% (66 of 107) of the neuroepithelial tumors. However, the detection rates of telomerase activity were widely different for different histopathological entities. In the case of astrocytic tumors, the detection rate was 20.0% (3 of 15) for grade II astrocytomas, 40.0% (6 of 15) for anaplastic astrocytomas, and 72.3% (34 of 47) for glioblastomas. The mean TRF length of the tumors with telomerase activity was significantly shorter than that of the tumors with undetectable telomerase activity for each tumor entity. In grade II and anaplastic astrocytomas, telomerase activity was an indicator of early histological progression and reduced survival of the patients, although there was no difference in MIB-1 staining indices between the tumors with and without telomerase activity at onset. In three astrocytic tumors, concurrence of telomere shortening and telomerase reactivation was observed at recurrence; in these cases, tumors progressed to a higher grade. Ten glioblastomas that progressed from lower-grade tumors exhibited telomerase activity, and their TRF lengths were reduced in 80% (8 of 10). In contrast, telomerase activity was detected in only 63.3% (19 of 30; P < 0.05) and the TRF length remained compatible with normal values in 56.7% (17 of 30; P < 0.01) of de novo glioblastomas. Thus, telomerase activity strongly correlated with potential tumor progression in the short term as well as with progression itself of the astrocytic tumors, whereas telomeres may still have been in the process of shortening in some of the de novo glioblastomas. High telomerase activity was exhibited in all primitive neuroectodermal tumors, anaplastic oligoastrocytomas, neuroblastomas, and oligodendrogliomas. TRF length was reduced in the majority (14 of 15) of three previously high-grade tumors, whereas it was compatible with that of normal brain tissues in the oligodendrogliomas, suggesting that telomerase activity with shortened telomeres correlates with the aggressive growth of high-grade neuroepithelial tumors. Tumor cell lines could be established from 17.2% (5 of 29) of neuroepithelial tumors with telomerase activity but not from tumors without this activity (P < 0.05), suggesting that telomerase reactivation is an essential event in the neuroepithelial cell immortalization in vitro. In nonneuroepithelial tumors, telomerase activity was detected in malignant tumors, such as germ cell tumors, lymphomas, metastatic adenocarcinomas, hemangiopericytomas, and an anaplastic meningioma. In contrast, such activity was not detected in benign tumors, including meningiomas, pituitary adenomas, hemangioblastomas and schwannomas, except for one hemangioblastoma that recurred four times and displayed malignant features at the fourth recurrence. These findings suggest that telomerase activity can be an index of malignant potential or malignancy itself in nonneuroepithelial brain tumors.

Color vision in two observers with highly biased LWS/MWS cone ratios.

Two sisters, heterozygous carriers for congenital X-linked protanopia, were diagnosed as normal trichromats by the Rayleigh match on the anomaloscope. The heterozygous state was established by molecular analysis of their visual pigment genes. The normal color match establishes that the spectral sensitivities of their long-wavelength-sensitive (LWS) and middle-wavelength-sensitive (MWS) cone visual photopigments are within normal variability. Their FM 100-hue test error scores were low, demonstrating superior chromatic discrimination. Heterochromatic flicker photometric (HEP) spectral sensitivities were like those of protanopes. The estimated LWS/MWS cone ratios from the HFP data were 0.09/1 and 0.03/1, compared with ratios in the range of 0.6/1 to 10/1 for typical normal trichromats. Measurements of chromatic grating acuity on chromatically selective backgrounds were performed to study the cone mosaic. The data were consistent with a sparsity of LWS cones. Both protan carriers showed normal spectral sensitivities for all three cone types under cone isolating chromatic adaptation and normal three-peaked curves for increment thresholds on a white pedestal. Hue estimation, run on one carrier was normal. The equilibrium yellow locus was measured in the other carrier and was in the range of normal trichromats. The data indicate that normal color vision can occur even when the LWS/MWS cone ratio is quite abnormal.

[Usefulness of percutaneous microwave tissue coagulation therapy for solitary liver cancer].

The possible use of percutaneous transhepatic microwave tissue coagulation therapy (PMCT) using ultra-sonography under local anesthesia for solitary liver cancer was studied. The subjects were 8 patients having primary or metastatic liver cancer with solitary liver tumor less than 4 cm in size, consisting of 2 hepatocellular carcinomas, and 6 metastatic carcinomas. PMCT was performed continuously 3 times at the output of 30 watts for 30 seconds at a time. Tumors less than 3 cm in size were completely coagulated by irradiation from 2 to 5 times judged by enhanced CT. No recurrence of tumor was recognized in the coagulation area. But in some cases, multiple metastases were found at another site in the liver by 3 months after PMCT. Thus, the results suggest that PMCT is a useful therapy for small liver tumor as a local control.

[A case of advanced hepatocellular carcinoma with portal invasion effectively treated by continuous intra-arterial chemotherapy with 5-fluorouracil].

A 79-year-old male diagnosed as advanced hepatocellular carcinoma with portal invasion was treated by continuous intra-arterial chemotherapy of 5-FU, which was continuously administered for 72 hours at a dose of 333 mg/mm/day every 2 weeks and repeated 12 times. Total dose of 5-FU was 14.4 g. Toxicity of this therapy was not recognized. Levels of AFP were reduced from 4385.6 ng/ml to 11.9 for 6 months. No tumor was recognized on CT scan at 6 months after starting this therapy, after 15 months of this therapy, the patient is alive and disease-free. Given the above results, continuous intra-arterial administration of this 5-FU therapy may be effective for patients with hepatocellular carcinoma.

Contrast adaptation and the spatial structure of natural images.

Natural images have a characteristic spatial structure, with amplitude spectra that decrease with frequency roughly as 1/f. We have examined how contrast (pattern-selective) adaptation to this structure influences the spatial sensitivity of the visual system. Contrast thresholds and suprathreshold contrast and frequency matches were measured after adaptation to random samples from an ensemble of images of outdoor scenes or of synthetic images formed by filtering the amplitude spectra of noise over a range of spectral slopes. Adaptation selectively reduced sensitivity at low-to-medium frequencies, biasing contrast sensitivity toward higher frequencies. The pattern of aftereffects was similar for different natural image ensembles but varied with large changes in the slope of the noise spectra. Our results suggest that adaptation to the spatial structure in natural scenes may exert strong and selective influences on perception that are important in characterizing the normal operating states of the visual system.

Isolated dural metastasis from colon cancer.

We report a case of isolated dural metastasis from colon cancer. Neuroradiologic and intraoperative findings indicated that the tumor was extra-axial, and histopathologic examination resulted in the correct diagnosis. Notable neuroradiologic findings of the present dural-based tumor were: diploic fat MRI signal disappeared in the tumor associated calvaria where bony change was absent on bone-window CT; abnormal subgaleal and epidural tissues were seen on MRI, both of which contained clusters of adenocarcinoma cells histopathologically. These findings suggest an infiltrative, malignant character, and help to differentiate between benign and malignant dural-based tumors.

Color from motion: separate contributions of chromaticity and luminance.

'Color from motion' describes the perception of a spread of subjective color over achromatic regions seen as moving. The effect is produced with a stimulus display consisting of colored dots, randomly placed upon a white field, with dots in the test region differing in both chromaticity and luminance from those in the surround. Evidence is presented suggesting that color from motion may be regulated by mechanisms different from those for contour formation and color contrast. (1) Results based on ratings show that, in the absence of luminance differences between the dots in the test and those in the surround regions, chromaticity differences alone are sufficient to produce color spread from motion. As the equiluminance point is approached, subjective color spread is seen despite a reduction in the strength of the subjective contour. Thus, contour formation is not likely to be a prerequisite for color from motion. (2) Color matches show that the hue and saturation of the subjective color spread are determined largely by the chromaticity and the luminance of the dots in the test region, not by those of the dots in the surround for the values explored. This suggests that color from motion may arise in sites distinct from those responsible for the regulation of color contrast.

[Usefulness of subcutaneous implantable port with new one-way valve].

Because of the development of the subcutaneous implantable port, intra-arterial infusion chemotherapy for malignant tumor has been performed in safety and it is now possible to choose a more effective method of drug administration. Many problems remain, however. In this study, we investigated the performance of subcutaneous implantable port with a new one-way valve with safety, septum intensity and a back stream of blood. This new port was very safe, with good septum intensity and water backflow. In the performance test with a back stream of water into the catheter, water did not back up into the catheter connecting with the port with the one-way valve, but did so without the one-way valve after releasing a load of 2,000 g from the septum. This suggests that the catheter obstruction is decreased by adding a one-way valve to the port.

Profile of T-cell receptor V beta gene usage of cytotoxic T cells induced by intrapleural administration of a streptococcal preparation, OK432, in malignant effusions.

T-cell receptor (TCR) gene rearrangements were analyzed in tumor-infiltrating lymphocytes (TIL) using the reverse transcription-polymerase chain reaction (RT-PCR) to determine whether oligoclonal expression of TCRV beta occurs in TIL, and if so, whether it is involved in the clinical response and mechanisms of locoregional immunotherapy using a streptococcal preparation, OK432. Patients with malignant effusion of various origins were treated with intrapleural administration of OK432, and clinical responses were assessed by cytological and chest X-ray examinations. Pleural exudate cells (PEC), obtained before and after the administration of OK432 (designated as pre- and OK432-PEC, respectively), were subjected to TCR analysis. Both pre-PEC and OK432-PEC showed highly diverse expressions of TCRV beta gene usage in either type of PEC. The frequency of TCRV beta 20 gene expression in OK432-PEC was significantly higher than in pre-PEC. Moreover, the over-expression of the TCRV beta 20 gene usage was also induced in the peripheral blood lymphocytes and pre-PEC of patients by in vitro OK432 stimulation, but not in the PBL of one healthy volunteer. Single-strand conformational polymorphism (SSCP) analysis revealed the clonotypes of these TCRV beta 20 genes. Autologous tumor-specific killing activity could be detected in OK432-PEC and was significantly reduced by treatment with a TCRV beta 20-specific monoclonal antibody. These findings suggest that the rearrangement of TCRV beta 20 gene usage may be involved in the autologous tumor-specific action of malignant effusions in the treatment with OK432.