26. Klaunig J.E., Goldblatt P.J., Hinton D.E., Lipsky M.M., Trump B.F. (1984). Carcinogen induced unscheduled DNA synthesis in mouse hepatocytes. Toxicol Pathol. 1984;12(2):119-25. PMID: 11478312.
Abstract. Mouse primary liver cell cultures were examined for evidence of unscheduled DNA synthesis (UDS) following treatment with the carcinogens; dimethylnitrosamine (DMNA), diethylnitrosamine (DENA), 2-acetylaminofluorene (2-AAF), N-methyl-N’-nitro-N-nitrosoguanidine (MNNG), benzo(a)pyrene (BP), dimethylbenzanthracene (DMBA), 1,1,-bis(p-chlorophenyl)-2,2,2-trichloroethane (DDT), safrole, diethylstilbestrol (DES), aflatoxin B1 (AFB1), and dieldrin and the noncarcinogens; dimethylformamide (DMF), fluorene, and pyrene. Mouse hepatocyte cultures were simultaneously treated with three concentrations of each compound and 3H-thymidine. After 24 hrs, cells were fixed and processed for autoradiography. 3H-thymidine incorporation in both experimental and control cell nuclei, as evidenced by autoradiographic grains, was quantitated microscopically. DMNA, DENA, 2-AAF, MNNG, BP, AFB1 and DMBA significantly increased UDS over untreated cells at all concentrations studied. DDT, DMF, fluorene, pyrene, safrole, DES, and dieldrin were negative for UDS in all concentrations examined. DMNA, 2-AAF and MNNG were also studied for UDS induction in 2 hr old, 1 day old and 4 day old cultures. A progressive decrease in UDS with increased time after plating was found in DMNA and 2-AAF treated cultures. After 4 days DMNA and 2-AAF induced UDS only at the highest concentrations examined (10(-3) M and 10(-4) M respectively). MNNG induced UDS at all time periods and concentrations sampled. An attempt to enhance the sensitivity of the UDS assay by inducing the mixed function oxidative enzyme activity in the hepatocytes with phenobarbital administered in vivo resulted in no statistically significant increase in UDS with DMNA, 2-AAF, MNNG, DDT, and dieldrin when compared with cells from non-induced animals.
25. Selman S.H., Kreimer-Birnbaum M., Klaunig J.E., Goldblatt P.J., Keck R.W., Britton S.L. (1984). Blood flow in transplantable bladder tumors treated with hematoporphyrin derivative and light. Cancer Res. 1984 May;44(5):1924-7. PMID: 6231988.
Abstract. Following hematoporphyrin derivative (HPD) photochemotherapy, blood flow to transplantable N-[4-(5-nitro-2-furyl)-2-thia-zolyl] formamide-induced urothelial tumors was determined by a radioactive microsphere technique using either 103Ru or 141Ce. Two tumors were implanted s.c. on the abdominal wall of Fischer 344 weanling rats. HPD (10 mg/kg body weight) was administered 24 hr prior to phototherapy (red light, greater than 590 nm; 360 J/sq cm). One of the two tumors was shielded from light exposure and served as an internal control. Blood flows were determined in control animals that received no treatment (Group 1), HPD only (Group 2), or light only (Group 3). In Groups 4 and 5, animals received the combination of HPD and light but differed in the time interval between treatment and blood flow determinations (10 min and 24 hr, respectively). Only blood flow to tumors treated with HPD and light showed a significant decrease (p less than 0.05) when compared with their internal controls both at 10 min (Group 4) and 24 hr (Group 5) after completion of phototherapy. These studies suggest that disruption of tumor blood flow may be an important mechanism of action of this method of cancer therapy.
24. Kreimer-Birnbaum M., Baumann J.L., Klaunig J.E., Keck R., Goldblatt P.J., Selman S.H. (1984). Chemical studies with hematoporphyrin derivative in bladder cell lines. Prog Clin Biol Res. 1984;170:335-50. PMID: 6241683.
23. Jones R.T., Klaunig J.E., Sanefuji H., Hinton D.E. (1984). A Method for the Organ Explant Culture of Fish Kidney Tubules. Journal of Tissue Culture Methods, 7(4), 185-190.
22. Stoner G.D., Greisiger E.A., Schut H.A., Pereira M.A., Loeb T.R., Klaunig J.E., Branstetter D.G. (1984). A comparison of the lung adenoma response in strain A/J mice after intraperitoneal and oral administration of carcinogens. Toxicol Appl Pharmacol. 1984 Feb;72(2):313-23. PMID: 6695378.
Abstract. This study was undertaken to compare the ability of a series of compounds from different chemical classes to induce lung tumors in strain A/J mice after either ip or po administration. 3-Methylcholanthrene, benzo(a)pyrene, urethan, diethylnitrosamine, ethylnitrosourea, and dimethylhydrazine induced a significant (p less than 0.05; t test) increase in the lung tumor response when given both ip and po. 2,4-Dinitrotoluene, 2,6-dinitrotoluene, and a 2:1 mixture of 2,4-dinitrotoluene and 2,6-dinitrotoluene were inactive by both routes of administration and at all dose levels. The lung tumor response to all doses of 3-methylcholanthrene and benzo(a)pyrene, the highest dose of diethylnitrosamine, and the middle doses of both ethylnitrosourea and dimethylhydrazine varied as a function of the route of administration. This finding was most evident for the polycyclic hydrocarbons, e.g., the average number of lung tumors per mouse in animals that received the middle dose of 3-methylcholanthrene or the highest dose of benzo(a)pyrene by the ip route exceeded that by the po route by factors of 12 and 13, respectively. Tissue distribution and elimination studies were conducted in an effort to determine the basis for the observed difference in lung tumor response to 3-methylcholanthrene after ip or po administration. The data indicated that 3-methylcholanthrene persists for longer periods in the animals when given ip, thus potentially providing an extended carcinogenic stimulus. Extrapulmonary lesions observed at a higher than normal frequency at necropsy included peritoneal sarcomas (in 3-methylcholanthrene-treated mice), and both squamous cell carcinomas of the forestomach and abnormal lesions of the liver (in diethylnitrosamine-treated mice).
21. Klaunig J.E. (1984). Establishment of fish hepatocyte cultures for use in in vitro carcinogenicity studies. Natl Cancer Inst Monogr. 1984 May;65:163-73. PMID: 6431289.
Abstract. Methods were developed for the isolation and primary culture of rainbow trout (Salmo gairdneri) and channel catfish (Ictalurus punctatus) liver cells. Using a two-step perfusion technique, I isolated an average of 2.75 and 2.87 liver cells/g body weight from the trout and catfish, respectively. Hepatocytes represented 91.4% (trout) and 90.1% (catfish) of the total liver cells isolated. Both catfish and trout hepatocytes in primary culture displayed a linear decrease in survival with increased duration of culture. The DNA synthesis in the hepatocytes during culture showed a similar decrease with increased time in culture. Approximately 2.8% (trout) and 3.5% (catfish) of the hepatocytes exhibited nuclear labeling with [3H]dThd immediately after isolation. The labeling index decreased for hepatocytes from both species to 0% by the tenth day of culture. Activities of cytochrome P-450 and B-5 initially declined rapidly for both trout and catfish hepatocytes after placement in culture; however, these activities leveled off at low but measurable values for the first 8 days of culture. Unscheduled DNA synthesis (UDS) was induced in catfish and trout hepatocytes after exposure to dimethylnitrosamine, aflatoxin B1, benzo[a]pyrene, and N-methyl-N’-nitro-N-nitrosoguanidine. Trout hepatocytes displayed a decrease in UDS induction with aflatoxin B1 with increased age of the cultures. However, UDS induced by N-methyl-N’-nitro-N-nitrosoguanidine remained constant throughout the culture period.
20. Klaunig J.E., Barut B.A., Goldblatt P.J. (1984). Preliminary studies on the usefulness of medaka, Oryzias latipes, embryos in carcinogenicity testing. Natl Cancer Inst Monogr. 1984 May;65:155-61. PMID: 6749249.
Abstract. Medaka (Oryzias latipes) embryos were exposed continuously for 10 days to diethylnitrosamine (DENA) at concentrations of 25, 50, or 100 ppm. Following exposure and after hatching, the embryos were placed in clean, carcinogen-free water. Fish were sampled for pathological examination after 1 month, 3, and 6 months. Grossly visible liver tumors were evident after 3 months in 10 and 30% of the fish treated with 50 and 100 ppm DENA, respectively. Following 6 months exposure, 4% of the fish treated with 25 ppm, 15% of those given 50 ppm, and 43% of those treated with 100 ppm DENA contained liver tumors. Focal areas consisting of 10 to 40 highly basophilic cells in the liver were noted at all the exposure concentrations. The incidence of the focal areas increased proportionately with the concentration of DENA and the age of the fish. Liver tumors were examined by light and electron microscopy. Most of the hepatic tumors were moderate to well-differentiated trabecular hepatomas, although 2 cholangiomas and 2 poorly differentiated hepatomas were noted. No liver lesions or tumors were observed in controls.
19. Costantini M.G., Klaunig J.E., Goldblatt P.J. (1984). Kinetics of DNA repair synthesis induced by bleomycin and N-methyl-N-nitrosourea in isolated rat liver nuclei. J Exp Pathol. 1984;1(2):89-101. PMID: 6086016.
Abstract. Purified rat liver nuclei were incubated in the presence of a labeled deoxyribonucleoside triphosphate and bleomycin (an antitumor agent) or N-methyl-N-nitrosourea (MNU, a direct-acting carcinogen) to compare their abilities to induce DNA repair synthesis. It was found that bleomycin induced the incorporation of [3H]dTMP and, to a lesser extent, [3H]dCMP and [3H]dAMP, whereas MNU induced incorporation of [3H]dAMP exclusively. The bleomycin-induced DNA repair was linear with time, whereas the MNU-induced repair was more complex, requiring an induction period and lasting only 90 minutes. The extent of incorporation measured after a 15- or 30-minute preexposure to bleomycin was proportional to the time of preexposure and the repair reaction was completed within 30 minutes. The extent of incorporation measured after preexposure to MNU increased less than proportionally with the time of preexposure and the repair reaction lasted a total of approximately 90 minutes. The interactions between bleomycin and MNU damage and repair were also examined. It was found that, following preexposure to MNU and subsequent repair in the presence of bleomycin, the repair activities induced by the two compounds were not additive. Our data are in agreement with previous studies on the base excision induced by bleomycin and MNU and suggest that the in vitro nuclear system reflects the physiological changes induced by the interaction of a compound with DNA.
18. Selman S.H., Keck R.W., Klaunig J.E., Kreimer-Birnbau, M., Goldblatt P.J., Britton S.L. (1983). Acute Blood Flow Changes in Transplantable FANFT-Induced Urothelial Tumors Treated with Hematoporphyrin Derivative and Light. Surgical Forum, 34, 676-678
17. Selman S.H., Goldblatt P.J., Christoforidis A.J., Klaunig J.E., Collard R.K., Jhunjhunwala J.S., Kropp K.A. (1983). Osteoblastic lesions in a patient with a bladder filling defect. J Urol. 1983 Sep;130(3):522-5. PMID: 6887367.
16. Castonguay A., Lin D., Stoner G.D., Radok P., Furuya K., Hecht S.S., Schut H.A., Klaunig J.E. (1983). Comparative carcinogenicity in A/J mice and metabolism by cultured mouse peripheral lung of N’-nitrosonornicotine, 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone, and their analogues. Cancer Res. 1983 Mar;43(3):1223-9. PMID: 6825093.
15. Klaunig J.E., Goldblatt P.J., Hinton D.E., Lipsky M.M., Knipe S.M., Trump B.F. (1982). Morphologic and functional studies of mouse hepatocytes in primary culture. Anat Rec. 1982 Nov;204(3):231-43. PMID: 6130724.
Abstract. Mouse liver cells in primary culture were evaluated by high-resolution light microscopy (HRLM) and transmission electron microscopy (TEM). Cells after 2 hours of culture in L-15 medium supplemented with 10% fetal bovine serum were spherical in shape, and were either individual or in small clusters of up to ten cells. Following 1 day in culture, hepatocytes were flattened and usually found in groups. Bile canaliculus-like structures were apparent between hepatocytes. Tight junctions and desmosomes were also present along adjacent plasma membranes. Autophagic vacuoles were seen within the cytoplasm. After 2 days in culture, hepatocytes appeared more elongated and flattened than in earlier sampling periods. Both autophagic and clear vacuoles were seen in the cytoplasm. Mitochondria were present in a variety of shapes and sizes. Small bundles of microfilaments were frequently seen in the basal region of cross-sectioned cells. From the fourth until the eighth day in culture, hepatocytes displayed further progression of the morphologic changes seen after 2 days. Nuclear elongation and the projection of cytoplasmic pseudoinclusions into the nucleus were also evident after 4 days. Cytoplasmic and nuclear changes were eventually observed in all hepatocytes by the eighth day of culture. DNA synthesis in the cells during culture was investigated by autoradiography. The percentage of S-phase labeled cells was 0.1% after 1 day of culture. The labeling index increased to 1.02%, 3.14%, and 5.88% after 2, 4, and 6 days of culture, respectively. Synthesis of albumin by the liver cells was also detectable during the first 8 days of primary culture. A gradual drop in albumin synthesis was noted with increased time in culture. The percentage of hepatocytes that histochemically stained for gamma glutamyl transpeptidase (GGT) progressively increased from 0.01% of the cells after 2 hours culture to 3.14% of the cells after 8 days of culture.
14. Stoner G.D., Babcock M.S., Cothern G.A., Klaunig J.E., Gunning W.T. 3rd, Knipe S.M. (1982). In vitro transformation of rat esophageal epithelial cells with N-nitrosobenzylmethylamine. Carcinogenesis. 1982;3(6):629-34. PMID: 7116556.
Abstract. Using an explant/cell culture system, rat esophageal epithelial cells were transformed in vitro by exposure to N-nitroso-N-benzyl-N-methylamine (BMNA). Twelve esophageal explant cultures per group were exposed twice (at days 1 and 7) to 0.0, 2.5, 5.0 or 10.0 micrograms BMNA/ml of medium. After incubation for 60-90 days, epithelial cells in primary cultures treated with all three concentrations of BMNA could be subcultured and cell lines were developed. The number of primary cultures and the number of subsequently developed epithelial cell lines was carcinogen-dose-dependent. Cell lines could only be established from carcinogen treated explants. Electron microscopy revealed that the BMNA-treated cell lines contained morphological markers of esophageal epithelial cells; i.e., numerous tonofilaments and junctional complexes, even after prolonged subculture. By immunofluorescence, the cells reacted positively with antibodies prepared to mouse skin prekeratins (K1 and K2). Two cell lines (from the 5 micrograms BMNA/ml group) were able to grow in soft agar and produce palpable tumors upon injection into syngeneic recipients. These tumors possessed the histological features of squamous cell carcinomas.
13. Klaunig J.E., Goldblatt P.J., Hinton D.E., Lipsky M.M., Trump B.F. (1981). Mouse liver cell culture. II. Primary culture. In Vitro. 1981 Oct;17(10):926-34. PMID: 7309042.
Abstract. Mouse hepatocytes in primary culture were characterized. Hepatocytes were isolated by the two-step hepatic portal vein perfusion method described previously. An optimal cell attachment of 43% was noted after 2 h incubation in 10% fetal bovine serum. Minimal attachment (less than 7%) occurred in serumless medium. Serum concentrations above 10% and attachment durations greater that 2 h resulted in no increased attachment of viable cells. Nonviable cells, however, progressively attached when both of these parameters were increased. Survival data of the cells in culture resembled those reported for rat hepatocytes in primary culture. A progressive decrease in survival was noted following initial attachment until only approximately 15% of initially plated cells remained viable and attached after 8 d culture. The decrease in survival was accompanied by morphologic changes including flattening and elongation of the cells, some multinucleation, and disruption of monolayer groups.
12. Klaunig J.E., Goldblatt P.J., Hinton D.E., Lipsky M.M., Chacko J., Trump B.F. (1981). Mouse liver cell culture. I. Hepatocyte isolation. In Vitro. 1981 Oct;17(10):913-25. PMID: 6273298.
Abstract. A method for isolation of mouse liver cells by a two-step perfusion with calcium and magnesium-free Hanks’ salt solution followed by a medium containing collagenase is described. Several variations of the commonly used procedure for rat liver cell isolation were quantitatively compared with respect to cell yield and viability. The optimal isolation technique involved perfusion through the hepatic portal vein and routinely produced an average of 2.3 x 10(6) viable liver cells/g body weight. Optimal perfusate collagenase concentration was found to be 100 U of enzyme activity per milliliter of perfusate. Light and electron microscopic evaluation of liver morphology after several steps of the isolation showed distinct morphologic changes in hepatocytes and other liver cells during perfusion. After perfusion with Hanks’ calcium- and magnesium-free solution, many hepatocytes exhibited early reversible cell injury. These changes included vesiculation and slight swelling of the endoplasmic reticulum as well as mitochondrial matrix condensation. Subsequent to perfusion with collagenase, the majority of hepatocytes appeared connected to one another only by tight junctional complexes at the bile canaliculi. Multiple evaginations were seen on the outer membrane resembling microville and probably represented the remains of cell-to-cell interdigitations between hepatocytes and sinusoidal lining cells from the space of Disse. The cytoplasmic injury seen after Hanks’ perfusion was reversed after collagenase perfusion. After mechanical dispersion, isolated mouse hepatocytes were spherical in shape and existed as individual cells; many (80 to 85%) were binucleated under hase contrast light microscopy. By electron microscopy, cells appeared morphologically similar in cytoplasmic constitution to that seen in intact nonaltered liver cells.
11. Lipsky M.M., Hinton D.E., Klaunig J.E., Trump B.F. (1981). Biology of hepatocellular neoplasia in the mouse. III. Electron microscopy of safrole-induced hepatocellular adenomas and hepatocellular carcinomas. J Natl Cancer Inst. 1981 Aug;67(2):393-405. PMID: 6943377.
Abstract. A systematic, ultrastructural analysis wsa performed on safrole-induced hepatocellular adenomas and hepatocellular carcinoma(s) (HPC) in BALB/c mice. Adenomas were heterogeneous in cell composition containing dark-staining basophilic cells, pale-staining acidophilic cells, clear cells, and lipid-laden cells. Darkly staining cells resembled fetal hepatocytes. They had large nuclei with irregular borders and limited diversity of organelles. Rough endoplasmic reticulum was prominent and seen as parallel cisternae in single or double tracts often in association with mitochondria. Pale-staining cells contained abundant smooth endoplasmic reticulum. Other organelles were often displaced to the perinuclear or peripheral region of the cell. The clear cells resembled dark-staining or pale-staining cells but also containing large areas of glycogen deposition. Lipid-laden cells contained numerous, multisized lipid droplets in the cytoplasm. HPC contained cell types similar to those of the adenoma. In addition, they contained many anaplastic cells. These resembled hepatocytes but contained several other alterations. The most striking was an apparent increase in the number of altered mitochondria. The cytoplasm was often fluid with enlarged mitochondria with dense or pale matrices. The cristae were few and had altered configurations. Also, an apparent increase was seen in the number of microbodies. These were often clustered in one region of the cytoplasm. An increase in microbodies was also noted in other cell types of hepatocellular carcinomas. The results of this study demonstrated similarities in the cell types of the adenomas and HPC. This study also demonstrated differences, with the anaplastic cell being common only to the carcinoma. Due to the similarity of cell types, the adenoma should be considered a possible site of HPC development.
10. Lipsky M.M., Hinton D.E., Klaunig J.E., Goldblatt P.J., Trump B.F. (1981). Biology of hepatocellular neoplasia in the mouse. II. Sequential enzyme histochemical analysis of BALB/c mouse liver during safrole-induced carcinogenesis. J Natl Cancer Inst. 1981 Aug;67(2):377-92. PubMed PMID: 6943376.
Abstract. Sequential alterations in enzyme histochemical profiles and reaction of hepatocytes to rapid iron overload were examined in male BALB/c mice during chronic, safrole exposure. At 24 weeks after initiation of safrole treatment, foci of enzyme-altered hepatocytes were noted. These foci were composed of cells showing a decrease in reactivity for glucose-6-phosphatase (Glc-6-Pase) and succinate dehydrogenase (SDH) and an increase for gamma-glutamyl transpeptidase (gamma-Glu-T). In control, iron-loaded mice, the livers were intensely siderotic. In safrole-exposed, iron-loaded mice, foci of iron-negative hepatocytes, varying from a few cells to a lobule in diameter, were initially noted at 24 weeks. Both enzyme-altered and iron-negative foci occurred in the livers of exposed mice at all time periods after 24 weeks. After 36, 52, and 75 weeks of safrole treatment, hepatocellular adenomas were noted with altered enzyme histochemical profiles. Hepatocytes from adenomas were characterized by a decreased staining for Glc-6-pase and SDH and increased staining for gamma-Glu-T and glucose-6-phosphate dehydrogenase (Glc-6-PD). In addition, a few nodules showed a decrease in staining for 5’nucleotidase. In iron-loaded mice, hepatocytes of adenomas showed a decreased to negative reaction for iron when the surrounding parenchyma was siderotic. Hepatocellular carcinomas (HPC) occurred in livers of mice exposed to safrole for 52-75 weeks. The cells of HPC displayed similar enzyme histochemical reactions as cells of adenomas. They were decreased for Glc-6-Pase and SDH activity and increased for gamma-Glu-T and Glc-6-PD. In iron-loaded mice, the HPC cells were negative for stainable iron. Foci, adenomas, and HPC displayed some variability in enzyme histochemical reactions. Variability existed between lesions as well as between cells of the same lesion.
9. Lipsky M.M., Hinton D.E., Klaunig J.E., Trump B.F. (1981). Biology of hepatocellular neoplasia in the mouse. I. Histogenesis of safrole-induced hepatocellular carcinoma. J Natl Cancer Inst. 1981 Aug;67(2):365-76. PMID: 6943375.
Abstract. A sequential, histologic analysis of the livers of male BALB/c mice chronically fed the hepatocarcinogen safrole (4,000 ppm) was performed at 2, 4, 8, 16, 24, 36, 52, and 75 weeks. The transplantability of selected lesions to syngeneic hosts was also assessed. Histopathologic liver alterations at 2, 4, 8, and 16 weeks induced hypertrophy of centrolobular hepatocytes, oval cell proliferation, fatty change in periportal hepatocytes, including basophilic, acidophilic, and clear cell, were noted. At 36 and 52 weeks, hepatocellular adenomas occurred in 4 of 10 and 7 of 10 mice, respectively. At 75 weeks they occurred in 5 of 5 mice. Adenomas were larger than a lobule in diameter compressed the adjacent parenchyma, and distorted the hepatic architecture. Individual adenomas were composed of a mixture of basophilic, acidophilic, clear, and lipid-laden cells, arranged in disorganized cords, one to three cells in thickness. None of the 10 adenomas tested grew upon subcutaneous transplantation into syngeneic hosts. Hepatocellular carcinomas (HPC) developed in 2 of 10 safrole-exposed mice at 52 weeks and 3 of 5 mice at 75 weeks. These lesions were large, multilobed and, unlike adenomas, seemed to invade adjacent parenchyma. The HPC were heterogeneous in cell composition. Their architecture was disorganized with trabeculae of 1-10 or more cells in thickness. No central veins or portal tracts were seen. All HPC proliferated when transplanted into syngeneic hosts. The results of this study demonstrated a sequential development of altered hepatocyte populations leading to HPC in safrole-treated mice. The transplantability of HPC indicated their malignant nature.
8. Hinton D.E., Klaunig J.E., Jack R.M., Lipsky M.M., Trump B.F. (1981). Evaluation of the Channel Catfish Ictalurus punctatus (Rafinesque) as a Test Species in Chemical Carcinogenesis Studies. In Vitro, Journal of the American Society of Testing and Materials, 737, 226-238.
7. Lipsky M.M., Hinton D.E., Klaunig J.E., Goldblatt P.J., Trump B.F. (1980). Gamma glutamyl transpeptidase in safrole-induced, presumptive premalignant mouse hepatocytes. Carcinogenesis. 1980 Feb;1(2):151-6. PMID: 22282994.
Abstract. A histochemical procedure was used to determine the presence of gamma-glutamyl transpeptidase (GGT) in the livers of control, regenerating and carcinogen-treated mice. Young Balb/c mice were fed safrole, a naturally occurring hepatocarcinogen (0.4% w/w), for one year. Ten mice from control and ten mice from the safrole-treated group were killed at 4, 8, 16, 24, 36, and 52 weeks of exposure and 9 adult mice were killed after 2/3 hepatectomy. Basophilic and acidophilic foci of altered hepatocytes occurred in safrole-treated mice after 24 weeks. Neoplastic nodules appeared after 36 weeks. Both foci and nodules displayed elevated GGT activity as determined by enzyme histochemistry. Variability in the pattern of enzyme distribution and staining intensity was seen between cells of the same focus or nodule, as well as between different foci and nodules. Hepatocytes from regenerating livers of partially hepatectomized mice were negative for GGT. These results demonstrated a sequential development of carcinogen-altered hepatocyte populations characterized by the appearance of GGT activity prior to carcinoma formation. The results in the mouse show marked similarity to those reported in rat liver, where GGT has been used as a positive marker for premalignant liver lesions induced by a variety of carcinogens.
6. Lipsky M.M., Hinton D.E., Goldblatt P.J., Klaunig J.E., Trump B.F. (1979). Iron negative foci and nodules in safrole-exposed mouse liver made siderotic by iron-dextran injection. Pathol Res Pract. 1979 May;164(2):178-85. PMID: 461227.
Abstract. A procedure for the production of mouse hepatic siderosis is described which results in extensive iron deposition in all lobular zones. Mice exposed to safrole for 24 weeks displayed basophilic and acidophilic foci which did not accumulate iron. 36 weeks of dietary safrole exposure resulted in nodular lesions comprised of basophilic and hyalinized cells. The nodules displayed decreased or negative reactions for iron in hepatic parenchymal cells when the surrounding liver was siderotic.
5. Klaunig J.E., Lipsky M.M., Trump B.F., Hinton D.E. (1979). Biochemical and ultrastructural changes in teleost liver following subacute exposure to PCB. J Environ Pathol Toxicol. 1979 Mar-Apr;2(4):953-63. PMID: 109562.
Abstract. The response of the channel catfish liver to subacute exposure of polychlorinated biphenyls was evaluated using electron microscopic and biochemical techniques. After 21 days, treated fish displayed elevated microsomal enzyme activities. Morphologically, the liver produced several patterns of alteration involving the endoplasmic reticulum (ER). Structural alterations included an increase in tubular smooth ER, production of parallel stacks of smooth ER showing continuity with rough ER, and membranous whorls. Biochemical and morphologic findings were correlated in exposed livers, and the relationship of these findings to similar studies in other species of fish is discussed.
4. Hinton D.E., Klaunig J.E., Lipsky M.M. (1978). PCB-Induced Alterations in Teleost Liver: A Model for Environmental Disease in Fish. Marine Fisheries Review, 49, 47-50.
3. Lipsky M.M., Klaunig J.E. (1978). Comparison of acute response to polychlorinated biphenyl in liver of rat and channel catfish: a biochemical and morphological study. J Toxicol Environ Health. 1978 Jan;4(1):107-21. PMID: 416227.
Abstract. The acute response of liver of channel catfish and rat to polychlorinated biphenyl was compared on a structural and functional basis. Both the rat and the fish had elevated microsomal enzyme activities. However, in the rat the response was quantitatively greater in all respects. Morphologically, rats responded with lipid accumulation and marked increases in smooth endoplasmic reticulum. Fish liver showed lipid accumulation and increased profiles of rough endoplasmic reticulum with alterations in arrangement that appeared as vesicles and parallel cisternae. Minimal changes were seen in smooth endoplasmic reticulum, which appeared to be increased as discrete foci.
2. Doyle M., Koepp S., Klaunig J.E. (1976). Acute Toxicological Response of the Crayfish (Orconectes limosus) to Mercury. Bulletin of Environmental Contamination and Toxicology, 16, 422-424.
1. Klaunig J, Koepp S, McCormick M. Acute toxicity of a native mummichog population (Fundulus heteroclitus) to mercury. Bull Environ Contam Toxicol. 1975 Nov;14(5):534-6. PMID: 1203564