Fiberoptic bronchoscopic photoradiation in experimentally induced canine lung cancer

The potential of diagnostic and therapeutic applications of a system using hematoporphyrin derivative (HpD) and laser photoradiation for the localization and treatment of canine lung cancer experimentally induced in the bronchi was studied. Seven cases of canine invasive squamous cell carcinoma were used in this experiment. A dose of 2.5-3.0 mg/kg body weight HpD was administered intravenously in each dog forty-eight hours prior to examination for fluorescence. The violet light source was a krypton ion laser beam. The beam was transmitted via a quartz fiber inserted through the fiberoptic bronchoscope, and an image intensifier was used to detect the fluorescence from the bronchial foci. An argon dye laser was used for treatment of the foci with red light. Six of seven dogs with squamous cell carcinoma revealed fluorescence at the foci. Conversely, the bronchi of controls, consisting of normal dogs, showed no fluorescence. Three dogs with squamous cell carcinoma received treatment. The therapeutic system consisted of photoradiation with an argon dye laser beam also transmitted via a quartz fiber inserted through the fiberoptic bronchoscope and a dose of 2.5-3.0 mg/kg body weight HpD was administered intravenously 72 hours before the procedure. All carcinoma cases showed complete responses.

Perfluoroctylbromide: a liver/spleen-specific and tumor-imaging ultrasound contrast material

The effect of perfluoroctylbromide (PFOB) on liver and tumor echogenicity was evaluated in rabbits. The echogenicity of the kidney, which is not affected by PFOB, was used as the basis for comparison in the liver studies. For the liver echogenicity study, sonography was performed on four rabbits, two with PFOB and two without PFOB, and four rabbits prior to and following the intravenous administration of 5 ml/kg PFOB. All livers were equal to or less echogenic than kidney in the control animals. All livers became more echogenic than kidney two days after administration of PFOB. The effect of PFOB on tumor echogenicity was evaluated in 18 rabbits with VX2 tumor implanted in the liver. Ultrasound studies of all rabbits were performed by the same physician before and two days after half the rabbits had received PFOB (5 ml/kg intravenously). The reviewers correctly identified all rabbits that received PFOB by visualization of an echogenic rim around the hepatic tumors.

Ultrasonic contrast enhancement of tissue by encapsulated microbubbles

Pilot studies have shown that gelatin encapsulated microbubbles (GEM) are readily demonstrable ultrasonic contrast agents. GEM injected into hepatic and renal blood vessels resulted in increased echogenicity of the parenchyma in normal rabbits. VS carcinoma implanted in the rabbit liver and kidney showed significantly different echogenicity from that of normal parenchyma following GEM injection. Echogenic bubbles were delivered to different regions by varying the size of GEM.

Noncontact detection of experimental amelanotic ocular melanoma with L-3-123I-iodo-alpha-methyltyrosine

An application of L-3-123I-iodo-alpha-methyltyrosine for the detection of ocular melanoma is presented. In rabbits with malignant Greene amelanotic melanoma transplanted to the anterior chamber of the eye, all tumors were detected in positive contrast using a gamma camera with a single pinhole collimator. The smallest tumor identified weighed 65 mg. Our data are compared with those obtained with 32PO4, 67Ga, 203Pb or labelled iodochloroquine.

Nuclear magnetic resonance imaging of the abnormal live rat and correlations with tissue characteristics

Nuclear magnetic resonance (NMR) images of live rats with sterile and pyogenic abscesses, hematomas, and various implanted and spontaneous neoplasms demonstrated good contrast differentiation between pathologic and surrounding normal tissues. This differentiation was maximal when both the T1 and T2 tissue relaxation times were used as criteria. Neoplasms have a broad range of T1 and T2 values and may be confused with abscesses or hematomas. Tissue rate constants (1/T1 and 1/T2) are mainly dependent on total water content, the exception being fat, which has a 1/T2 value much shorter than that expected on the basis of water content alone.

Separation of two populations of cells with gamma-glutamyl transpeptidase from carcinogen-treated rat liver

Noninbred Sprague-Dawley rats were maintained on a choline-deficient diet containing 0.05% ethionine. After 10-13 weeks, livers were dispersed with collagenase, lysozyme, collagenase and hyaluronidase. Pronase, or a selected batch of trypsin. The highest yield of cells with histochemically demonstrable gamma-glutamyl transpeptidase (GGT) was obtained with trypsin. After velocity sedimentation in an isokinetic gradient of Ficoll in tissue culture medium, two modal populations of cells with histochemically demonstrable GGT were observed. The first mode contained cells that were morphologically different from hepatocytes and that may be oval cells. The second, more rapidly sedimenting modal population of cells with GGT was morphologically similar to hepatocytes as assessed with Wright's stain; the location of this population in the gradient was the same as the location of cells with the appearance of hepatocytes that lacked iron and that had decreased glucose 6-phosphatase. In multiple experiments, the purest fractions contained 71.7 +/- 3.5% cells (mean +/- SD) with the appearance of hepatocytes with histochemically demonstrable GGT.

Effects of prostaglandin on experimental bone malignancy and on scintigrams of bone and marrow

The correlation between prostaglandin E (PgE) and scintigrams of bone (Tc-99m MDP) and bone marrow (Tc-99m SC) was investigated in normal and VX-2-bearing rabbits. PgE in plasma of normal rabbits was 486.2 +/- 185.7 pg/ml (n = 86) and the maximum-to-minimum (max/min) ratio was 1.85 +/- 0.26 at 4 wk after tumor implantation. In rabbits with VX-2 transplanted into femoral muscles, PgE was in the normal range unless the tumor invaded bone. PgE did not increase significantly in rabbits when the tumor was transplanted into the marrow cavity. When tumor invaded bone, PgE increased markedly (to 1335 +/- 584 pg/ml). Elevation of PgE did not necessarily coincide with the appearance of positive bone scans. PgE in an indomethacin-treated group was not higher than in the untreated group. There was no significant difference between the two groups regarding the time of appearance of abnormal bone scans. However, when the number of transplanted cells in the bone marrow was reduced, the treatment with indomethacin delayed the increase in tracer uptake in the affected bone and resulted in a photon-deficient area. Indomethacin may suppress the local acceleration of calcium metabolism.

Synthetic porphyrins as tumour-localizing agents

A series of radioactively labelled porphyrin analogues have been synthesized and compared for tissue distribution and tumour uptake against 67Ga in the same tumour-mouse system. The compounds were: 14C-ms-tetraphenylporphine sulphonate (14C-TPPS), 35S-ms-tetraphenylporphine sulphonate (TPP35S), 35S-ms-tetra[beta-naphthyl]porphine sulphonate (TNP35S), 14C-ms-thienylphenylporphine sulphonate (14C-TTPPS) and 35S-ms-tetra[p-tolyl]porphine sulphonate (TTP35S). 14C-TPPS and TNP35S appear to concentrate in tumours to a greater extent than 67Ga (ratios of tumour uptake for TPPS/67Ga and TNPS/67Ga were about two and three respectively) but their uptake in kidneys and lungs was also greater than that of gallium. The type of side group attached to the central tetrapyrrole ring appears to have a substantial effect on the tumour-localizing properties of these compounds. Comparison of 14C and 35S-labeled TPPS indicates that the sulphonate groups are split off in vivo and that compounds with highly aromatic side groups (e.g. TNPS) and a radioactive label in a non-labile part of the molecule (e.g. in the tetrapyrrole ring system itself) would show even better tumour localization. The feasibility of synthesizing porphyrins with a variety of reactive side groups suggests that it may be possible to introduce suitable gamma-emitters while retaining the tumour-localizing properties.

Endoscopic detection of experimentally induced colonic neoplasms in guinea pigs (Cavia porcellus)

Colonoscopic examination was performed daily on 18 normal guinea pigs for 7 weeks and on 27 guinea pigs after 24-35 weeks of biweekly intrarectal instillation of the chemical carcinogen methylnitrosourea. Four normal guinea pigs died during the first 2 weeks of the study, two from colonic perforations and two from cecal bloating due to excessive air insufflation. The other 14 normal animals remained clinically healthy and had no gross abnormalities at the end of the 7-week study. Colonic tumors were detected by colonoscopy in five of seven treated guinea pigs that had grossly visible nodular tumors on the mucosal surface of surgically resected colonic tissue. In another treated guinea pig, a tumor was detected by colonoscopy which was not confirmed grossly. In an additional two treated guinea pigs, tumors were visualized by colonoscopy which could not be demonstrated in surgically resected tissue because of their inaccessible location within the pelvic canal. At necropsy, these latter two guinea pigs had nodular, mucosal growths in the pelvic portion of the colon as indicated by colonoscopy. Microscopically, an additional 13 cases of colonic neoplasms were identified in the resected colonic tissue without gross or colonoscopic evidence of intralumenal nodular growth.

Field focusing n.m.r. (FONAR) and the formation of chemical images in man

The first proposals for n.m.r. scanning in medical diagnosis was made by Damadian (1971a; 1972) and were followed by Lauterbur (1973). Damadian's method of scanning used the principle that the forced precessions of a nuclear magnetization under radio frequency (r.f.) driving field specify the conditions for obtaining spatial resolution of the signal producing domains of a nuclear resonance sample. Sufficient coupling of the nuclear spins to the radiation field to produce a signal detectable by r.f. spectroscopy requires that the stringent Bohr frequency condition, hv = microH0/I, be met. It became possible to construct, with the aid of direct current auxiliary coils, a small volume, called the resonance aperture, inside the applied static field of the magnetic resonance experiment. The correct value of H0 for the applied frequency is restricted to this aperture. The technique (Damadian 1972) was developed to provide a method for non-surgically detecting chemical abnormalities in the diseased organs of patients (Damadian 1971a). The first n.m.r. scans of normal patients and of those with malignant disease are discussed.

Gelatin encapsulated nitrogen microbubbles as ultrasonic contrast agents

Gelatin encapsulated nitrogen microbubbles were effective ultrasonic contrast agents in in vitro phantom and in vivo rabbit V2 carcinoma studies. Intra-arterial injection of 80-micrometer gelatin encapsulated nitrogen microbubbles appeared to improve tumor visualization by rim enhancement, which persisted for several minutes.

Mathematical models of cancer and their use in risk assessment

Cancer risk assessment necessarily involves the use of mathematical models. Although risk estimates can be extremely sensitive to underlying assumptions in such models, the assumptions are frequently overlooked when a particular model is used. This paper presents four examples to illustrate how the alteration of assumptions can have a large effect on risk estimates. Ways of avoiding undue model dependence are discussed.

Tumor location detected with radioactively labeled monoclonal antibody and external scintigraphy

Murine teratocarcinomas were located in mice by external gamma-ray scintigraphy with an iodine-125-labeled monoclonal antibody specific to the tumors. The specificity of the method was increased by subtracting the radiation produced by an iodine-125-labeled indifferent monoclonal antibody of the same immunoglobulin class as the tumor-specific antibody.

Models for development of nonreceptor methods for distinguishing androgen-sensitive and -insensitive prostatic tumors

From the original Dunning R-3327 rat prostatic adenocarcinoma, several distinct sublines have been obtained. These sublines include a well-differentiated, slow-growing, androgen-sensitive tumor (R-3327-H); a well-differentiated, slow-growing, androgen-insensitive tumor (R-3327-HI); and a fast-growing, androgen-insensitive, anaplastic tumor (R-3327-AT). These three sublines were compared in order to develop new model methods for the prediction of the androgen sensitivity and the degree of differentiation of prostatic adenocarcinomas. The R-3327-AT was very distinct in all parameters examined except the tissue protein electrophoretic patterns which contained a uniform pattern in all tumors. The significant differences between R-3327-H and -HI sublines were (a) the inability of testosterone to stimulate DNA synthesis in the R-3327-HI tumor and (b) the difference in the enzymatic profiles of these sublines. The specific activity of three enzymes (3 alpha-hydroxysteroid dehydrogenase, leucine aminopeptidase, lactic dehydrogenase) increased while the activity of another three enzymes (6 alpha,7 alpha-hydroxylase, 5 alpha-reductase, alkaline phosphatase) decreased in the sublines which are androgen insensitive and less differentiated. An arbitrary index was constructed, based upon these enzyme differences, which clearly discriminates the degree of androgen sensitivity and differentiation of these R-3327 rat prostatic adenocarcinomas.

Immunodiagnosis of mesothelioma: use of antimesothelial cell serum in an indirect immunofluorescence assay

Cells isolated from human serous effusions were cultured in vitro. Monolayers of large multipolar cells were established. Antisera to the cultured cells were prepared in rabbits and rats. The antisera were absorbed with human red cells, liver powder and MOLT-4F cell line lymphocytes. Specificity of the absorbed antisera for human mesothelial cells were demonstrated in an indirect immunofluorescence assay. The antisera were used to confirm the diagnosis of mesothelioma in two cases. In both the patients, the morphologically identifiable malignant cell populations in the effusions stained positively with the antimesothelial cell serum thus establishing their mesothelial origin. Normal nonmesothelial tissue and known nonmesothelial tumors failed to react with the antisera thus confirming the specificity of the antisera.

Technetium-99m stannous citrate brain-tumor uptake in mice: concise communication

The pharmacodynamics of technetium-99m stannous citrate were studies in Yale-Swiss mice bearing a sarcoma-like transplantable brain tumor, and the renal kinetics were determined in normal mice. Using a rating system based on tumor uptake and tumor-to-brain, tumor-to-blood, and tumor-to-skin ratios, the data obtained with this compound were compared with similar data obtained previously in the same model with Tc-99m Fe-(ascorbic acid), Tc-99m Fe-(ascorbic acid)-DTPA, Tc-99m Sn-DTPA, [99mTc] pertechnetate, and [99mTc] pertechnetate with perchlorate predose. Technetium-99m stannous citrate does not appear to achieve tumor localization by a mode different from these other Tc-99m-labeled compounds, nor does it show any potential advantage as a scanning agent in the tumor model.

Radioactive nucleic acids-precursors: their potential value as tumor-localizing agents

The distribution of 125I-uracil and 125I-deoxyuridine in tumor-bearing animals has been studied. 125I-deoxyuridine shows the characteristics of a tumor-scanning agent. The metabolic incorporation by tumors of this DNA-precursor indicates a potential value of this radiocompound for their detection, differentiation and follow-up of their evolution after therapy.

Localization of GW-39 human tumors in hamsters by affinity-purified antibody to carcinoembryonic antigen

With the paired-labeled antibody technique, the in vivo localization of radioiodinate, affinity-purified antibody to carcinoembryonic antigen (CEA) was studied in GW-39, a xenografted, CEA-producing tumor model. When compared to the whole immunoglobulin G fraction, a 4-fold greater tumor accumulation of radioantibody was obtained with affinity-purified specific CEA antibody. The degree of increased tumor localization of affinity-purified antibody was similar to its improved immunoreactivity as observed in radioimmunoassay and binding to CEA immunoadsorbent. Affinity-purified antibody cross-reactive with CEA and colon carcinoma antigen III was as equally effective in tumor localization as was specific CEA antibody prepared similarly. It thus appears that affinity-purified CEA radioantibody will provide a superior tumor-imaging agent for clinical use.

Chronicled metastases in a hamster melanoma

Fortner's Melanotic Melanoma No 1 was inoculated into the right hindfoot of 86 golden hamsters. Three, 7, 14, 21, and 28 days after inoculation, groups of hamsters underwent amputations at the ipsilateral hindhip to determine when pulmonary metastases initially occur. Upon subsequent sacrifice of the hamsters, pulmonary metastases were found to occur initially within 14 days of tumor inoculation.

Comparison of I-bleomycin prepared by two methods stability and pharmacokinetics in tumor-bearing mice

Bleomycin, a chemotherapeutic antibiotic agent, was radio-iodinated by the ICI and chloramine-T methods; the radiochemical stabilities and pharmacokinetics of the two I-bleomycins in tumor-bearing mice were compared. The ICI preparation was more stable with respect to deiodination in vitro. Both products were sufficiently stable in vivo that high body background due to free isotope, a disadvantage of 111In- and 99mTc-bleomycin, was not encountered. Tumor uptake of the ICI preparation was constant from 2 to 24 hrs., and the tumor/blood ratio increased with time; with chloramine-T, this ratio decreased, and was less than that for ICI. The two preparations are chemically and biologically different; the ICI product is the superior tumor radiodiagnostic agent.

Carbon-11-labeled methylated polyamine analogs: uptake in prostate and tumor in animal models

The polyamines putrescine, spermine, and spermidine were methylated by the addition of carbon-11-labeled formaledehyde followed by sodium borohydride. High labeling yields wrbon-11-labeled formaldehyde followed by sodium borohydride. High labeling yields were obtained and the final products were purified by simply boiling the solution. This decomposed the excess sodium borohydride and removed the volatile impurities. The final radiochemical purity of all the methylated compounds was above 85%. All three methyltated compounds accumulated in the prostates of male rats and the distribution of N-methyl-1,4-diaminobutane (the putrescine analog) was very similar to that previously obtained with tritiated putrescine. The uptake of the putrescine analog in both the prostate and in mouse tumor was slightly higher than that obtained with the other two analogs studied. Utilizing a positron transaxial tomographic scanner and the putrescine analog, we have been able to image the prostate gland of a dog.

Metal isotopes used as radioactive indicators of ocular melanoma

We studied radioactive metal compounds to determine their localization in malignant Greene melanoma in the eye of the Syrian golden hamsters. Scintigraphy of an ocular melanoma was achieved with several radioactive metals: radioactive indium(111In)-bleomycin, radioactive gallium (67Ga)-citrate, and radioactive lead (203Pb)-tris. The 111In-bleomycin had the highest tumor uptake (5.45% dose/g), but not the highest tumor-to-background ratios. The 67Ga-citrate had a maximum tumor uptake of 4.87% dose/g at 48 hours. The 111In-chloride had a melanoma uptake of 2.26% dose/g, while with 203Pbtris the uptake was 1.61% dose/g. These uptake ratios compare favorably with that of radioactive phosphorus (32P)-2.21% dose/g. Noninvasive localization of malignant melanoma in the eye was accomplished with metal isotopes. Detailed analysis of in vitro uptake date by tumor and background tissues revealed the optimum time for scanning and precluded unnecessary trials.

Carboxyl-labeled 11C-1-aminocyclopentanecarboxylic acid, a potential agent for cancer detection

Carboxyl-labeled 11C-1-aminocyclopentanecarboxylic acid (11C-ACPC) has been prepared in multimillicurie amounts. The conversion of H11CN to 11C-ACPC (t1/2 = 20.4 min) was accomplished by a rapid (20-min) two-step high-temperature modification of the Bücherer-Strecker amino acid synthesis technique, which should be applicable at other accelerator installations. Purification was by ion exchange techniques. Animal studies have indicated that 11C-ACPC is a potential tumor-localizing agent for detecting cancer in humans by nuclear medicine scanning techniques.

[Animal experimental studies of positive tumor demonstration with radio-iodine labelled albumin macroaggregates]

131I-labeled macroaggregates were injected into the femoral artery of rats bearing a Yoshida sarcoma at the lower extremity and of healthy control animals. The radioactivity was measured in tissue samples taken from the tumour and in unaffected muscle tissue. The tumour tissue showed a considerably higher uptake of radioactivity than the not-neoplastic tissue of control animals. The difference was increased when more time elapsed between the injection and the measurement. After 48 hours the ratio was 25:1 in favour of tumour tissue. In contrast to the transplanted Yoshida sarcoma, hepatomas in Wistar rats induced by N-nitroso-morpholin showed a considerably smaller increase of radioactivity than the control group when injected with 131I-MAA. The fixation ratio between tumour and normal liver tissue was 1:5.9. In contrast to autochtone liver tumours rats with transplanted tumours are considered as a suitable model for testing labeled albumin particles like 131I-, 111In- or 99mTc-labelled albumin microspheres developed for angioscintigraphic purposes.

Labelling and metabolism of methionine-methyl-11 C

Carbon 11 which is a 20.4 minutes half life isotope emitting positrons was used for methionine labelling on the methyl group by action of 11C-methyl-iodide on DL or L homocysteine. With the method described, 20 to 30 mCi of 11C-methyl-methionine (Specific activity 50 mCi/muM) may be obtained within 25 minutes. The 20 Mev proton beam used for 11C production was 10 muA. The metabolism of 11C methionine studied on mice shows a high uptake in pancreas and to a smaller extent in brain. On humans sequential images were obtained at the head level which allowed measurement of the uptake of the radio-labelled compound in the brain so as to study the radioactivity curve in different parts of the organ.

Flow microfluorometric system for screening gynecologic cytology specimens using propidium iodide-fluorescein isothiocyanate

Seventy cervical cytology specimens have been screened by a xero resolution flow analyzer-sorter using propidium iodide and fluorescein isothiocyanate as fluorochromes for nucleus and cytoplasm, respectively. This system shows a 1% sensitivity for detection of abnormal cells using only crude visual data analysis. Screening of clinical specimens was performed on the instrument with a 5.8% false negative rate and a 11.8% false positive rate by comparison with routine visual cytologic evaluation of the same samples.

Evaluation of endoscopic examination of colon tumors in rats

This study is an evaluation of the use of endoscopic examination to detect MNNG-induced large-bowel tumors in rats. The smallest human fiberbronchoscope was used as a colonoscope for the rats and the full length of the distal large bowel was visualized. The correct diagnosis rate in all rats with and without large-bowel tumors was 94%. Of rats with colon tumors, 85% were correctly diagnosed endoscopically. Even tumors 1 or 2 mm in diameter were detected. The examination was easy and reliable. This procedure may be an adjunct in experimental work with this and other animal models of colon cancer.

Tumor localization of 131-I-labeled antibodies by radionuclide inaging

Intravenous injections of 131-I-labeled anti-EL4 lymphoma antibodies showed progressive localization of radioactivity in EL4 transplants but not in B16 melanoma in mice carrying both tumors. Normal rabbit globulin labeled with 131-I did not localize in either tumor and cleared more slowly from the internal organs. Metastatic localization of intravenous 131-I-labeled anti-tumor antibodies was also observed in 2 cancer patients.

Tissue water content and nuclear magnetic resonance in normal and tumor tissues

Pulsed proton nuclear magnetic resonance was used to differentiate between normal and malignant tissues. When the tissue water content varied from 80 to 93%, the tumors exhibited spin-lattice relaxation times (T1) from 0.9 to 1.8 sec. We report also the results obtained on 9-day-old embryos and on liver, brain, and heart from 2-day-old rats. A good correlation between the spin-lattice (T1) and spin-spin (T2) relaxation times and the tissue water content was found for all tissues studied. The relaxation times T1 and T2 and water content in Walker 256 carcinoma and its lymph node metastasis were quite similar.

Prostaglandins in mice with neuroblastoma

Male albino mice, with and without transplanted neuroblastoma C1300, had tissues analyzed for prostaglandins by radioimmunoassay. Highest prostaglandin concentrations occurred in tumor tissue, lungs, spleen, and kidneys. Tritiated prostaglandins A1 or E1 and tritiated arachidonic acid were injected intravenously. The concentration (organ/tumor) was higher at 1 hr than at 6 or 24 hr. Prostaglandin E1 and arachidonic acid localized principally in the kidney (likely the excretory organ) whereas prostaglandin A1 showed highest concentration in the liver.