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675 676

Measurabsnt of the Electric impedance of a Fulmmary mss - application to needle biopsy - Sugum Kimra, M.D., Tadacki Morimoto, M.D., Tadashi Uyam,

M.D., Yasumsa Mm&n, M.D. Second Department of Surgery, School of Medicine, ?he university of mkushima, Japan

After the general anesthesia and thorawtcmy, the im-nce of a pAmmary mass was mwsured in 53 patients (included 44 lung cancers, 5 metastatic lung tmkxs and 4 with organizing plemmnia). 'Ihe biological tissue can !x regarded electrically to consist of extracellular resistance (Re), intiacellular resistance (Ri), and the electrical capacitance of the cell membrane CC). lilese three parameters were calculated from the measured electrical impedance of tissue by the curve fitting technique using a cmputer program. It was found that the Re of lung tissue was signifi- cantly higher than that of a plln8mm.y mss (p<O.Ol), that the On of lung tissue was significantly lmer than that of a pulmnary mass (ptO.O1). lhe Re of malignant tars (lung cancer and me- tas'catic tars) was significantly higher than that of organizing pneumnia (ptO.Ol), ard the Cm of mliqnant tumors was siqnifi- cantly lower thm that of organizing pneunnnia (p<O.Ol). With this knmledqe, we used a biopsy needle to locate and the diagnose intrathoracic lesions. 'Ihe electrical impedance of the lung mass in 9 patients vas measured using a modified impedance analysis system (measurement were made three times per second) throuqh the biopsy needle before a biopsy was performed. mere uas no false negative result, but there was one false pxitive result. This technique allowed us to confirm the proximity of the needle tip tc the mss. Ihe rapid measurement of electrical impedance of a pulmonary mass in preupxatively may be of value in the clinical evaluation of a pl1nvmu.y mss both by quidinq the needle for biopsy and by diagnosing the mss based on its electrical impedance.

677

QUANTITATIVE RADIONUCLIDE ANGIOGRAPHY IN ASSESS- MENT OF HEMODYNAMIC CHANGES AFTER LUNG RESECTION

Shimoyama H, Fujisawa K, Yamada T, Indo H, Yoshida E, !<urokawa T Devision of Surgery, Saiseikai Imabari Hospital, Imabari 799-15, JAPAN

Method: Twenty cases of resected lung cancer (4 pneu- monectomies,l4 lobectomies,2 partial lung resections) were subjected in this study. Right and left ventri- cular function were measured by gated blood pool scintigraphy preoperatively and on postoperative day (POD) 7 and POD 21. Cardiac function during surgery until1 POD2 was also monitored by Swan-Ganz catheter. Results: l.Right ventricular function Right ventri- cular after-load at the operative day and right vent- ricular preload on POD 1 were noted,followed by dis- appearance of right ventricular overload on POD 2. 2.Left ventricular function Left ventricular ejection fraction (LVEF) decreased gradually until1 POD 21, noted by gated blood pool scintigraphy. Remarkable decrease of LVEF was observed in pneumonectomy cases. Decrease of time to peak flow rate (TPFR) was.also observed at POD 7. Moreover,TPFR of pneumonectomy cases continued decreasing until1 POD 21. However pneumonectomy cases which received oral dopamin after POD 7 showed improvement of left ventricular overload and disappearance of shortness of breath. Conclusion: Right ventricular overload was observed immediately after lung resection, subsequently left ventricular overload gradually advanced. Gated blood pool scintigraphy permits accurate and non-invasive assessment of these hemodynamic responses.

INJJKTIONOFKILLERCELUINMALI~~ EFWSIONS O&WNJID FROM LUNG CANCBtPATlENTS. Y. INOUB, N. SHIJUBO. M. ASAKAWA and A. SUZUKI

Dep. Int. Med., Sec. 3, Sapporo Med. Coll., Japan We analyzed the function of pleural exudative

lymphocytes (PLEL) obtained from malignant pleural effusions of 18 advanced lung cancer patients. PLEL were examined the phenotype by using monoclonal antibodies against CD3, CD4, CD8, CD16, CD20 and CD25, and the cytotoxicity against NK sensitive K562, LAK sensitive Daudi and autologous tumor cells, Freshly isolated PLEL were mainly CD4 positive T cells, and they had weak NK, LAK and autologous tumor killing activity. After cultivation in the presence of rIL-2. the proportion of CD8 positive cells was increased, however cytotoxicity of PEEL against autologous tumors wasn't enhanced greatly. When lymphocytes were stimulated by WC-treated autologous tumor cells during culture, stimulated PLEL demonstrated strong autologous tumor killing activity. Cold target inhibition analysis demon- strated that the cytotoxicity of stimulated PLEL against autologous tumor cells is specific (2 of 5 cases) or non-specific (3 of 5 cases). Binding inhibition assay indicated that in 2 of 5 cases, anti-CD3, CD8 and human MHC class I Ag antibodies inhibited cytotoxicity of stimulated PLEL against autologous tumor cells, but not anti-CD4 and human MHC class II Ag antidodies. These results suggested that autologous tumor stimulation could induce MHC class I Ag restrinct CTL specific for autologous tumor cells.

678

TARGET-SELECTIVE CYTOTOXIC ACTIVITY OF IMMUNOTOXINSTOTHECOh4MONSMALLCELLLUNG CANCER-ASSOCIATEDANTIGENS.

E.J. Wawrzynczakl, E.J. Derbyshiret, L. de Leijz, S. Menards & R. Stahel4. *Institute of Cancer Research, Sutton, U.K., ZUniversity Hospital, Groningen, The Netherlands, 3National Cancer Institute, Milan, Italy, 4University Hospital, Zurich, Switzerland.

Immunotoxins (ITS) were constructed by chemically coupling ricin A chain to a panel of mouse monoclonal antibodies (Mabs) representing each of five Mab clusters that recognise distinct antigens commonly associated with human small cell lung cancer (SCLC) as defined by the 2nd International Workshop on SCLC Antigens (Br.J.Cancer 63. SuppLXIV, 1991). The SEN36 IT (~1.1) was weakly cytotoxic inhibiting the incorporation of aH-leucine into SCLC cell lines in tissue culture by 50% at a concentration (IC50) of 20nM, comparable to the effects of unconjugated A chain and control ITS of irrelevant specificity. The SWAZO (cL5A) IT had modest cytotoxic activity with an IC50 of 0.2-2nM. The most potent cytotoxic effects were given by the MOC31 (~1.2). SWAll (~1.~4) and MOvl5 (~1.~6) ITS which had IC5Os of 30-200pM. 30-40pM and lo-50pM respectively. The SCLC- specific ITS at 1OnM showed no significant activity against a control human non-lung tumour cell line. The results of this comparative study indicate that A chain ITS to the ~1.2. ~1.~4 and ~1.~6 antigens display the most potent effects against SCLC and are the best candidates for IT therapy.