Procoagulant activity and tumor necrosis factor in rat hepatic allograft rejection

We used a model of rat hepatic allograft rejection to evaluate levels of procoagulant activity and tumor necrosis factor during acute cellular rejection. ACI livers were transplanted into Lewis rats, and Lewis-to-Lewis isografts and unoperated animals served as controls. Animals were killed on days 1, 2, 3, 4, 5, 6, 7 and 9. Splenic mononuclear cells were obtained by Ficoll-Hypaque gradients. Collagenase perfusion, metrizamide gradients and centrifugal elutriation were used to isolate Kupffer cells. Procoagulant activity assay of the splenic and Kupffer cells was done using a one-step clotting assay. Tumor necrosis factor was assayed using an L929 cytotoxicity assay. Histological evidence of acute rejection began on the 4th postoperative day, and rats died by the 9th or 10th postoperative day. Splenic procoagulant activity was significantly elevated in rejecting rats on day 4 and remained elevated until death. In contrast, Kupffer-cell procoagulant activity was elevated over controls by day 3 and remained significantly elevated until death. The tumor necrosis factor levels were elevated from day 1 and remained so until death. The data indicate that procoagulant activity is synthesized both by peripheral monocytes and locally by Kupffer cells and that procoagulant activity and tumor necrosis factor levels rise during hepatic allograft rejection. Because procoagulant activity and tumor necrosis factor mediate immune functions that are postulated to be important in acute rejection (immune cell adherence, vascular thrombosis and delayed-type hypersensitivity), these elevations may contribute to the pathogenesis of acute rejection.

Long survival in rats after multivisceral versus isolated small-bowel allotransplantation under FK 506

Abdominal multivisceral allotransplantation (MVTX) from Brown Norway donor rats to Lewis recipient rats was performed under a 14-day course of low (0.32 mg/kg) or high-dose (0.64 mg/kg) intramuscular FK 506 to which weekly further injections were added in some of the high-dose animals. With all three regimens, long survival was frequently achieved with good intestinal adsorption and weight gain, but histopathologic evidence of intestinal rejection existed in the most lightly treated animals. The liver, stomach, and pancreas had only minor abnormalities. Rejection of isolated intestinal grafts was more difficult to control based on histopathologic criteria, and satisfactory results were obtained only with the most aggressive treatment protocol, suggesting that the liver in the MVTX had provided an advantage to the companion organs of the graft, of which the intestine was most vulnerable. Histopathologically, the lymphoid elements of the intestine, including the Peyer's patches, appeared to be the most immunogenic component of the intestine. Epithelium near lymphoid areas was secondarily involved with villous atrophy, cryptitis, and abscess formation. Beginning within 12 days in successful MVTX experiments, the lymphoreticular components of the graft intestine, including the Peyer's patches, lamina propria, and mesenteric nodes, were shown with anti-Ia monoclonal antibodies to be repopulated with recipient cells. This finding in grafts that appeared to be permanently accepted was surprising and contrary to expectations from the literature on intestinal allotransplantation.

Early events in liver allograft rejection. Delineation of sites of simultaneous intragraft and recipient lymphoid tissue sensitization

The early events of liver allograft rejection in untreated rats were studied in the DA to BN rejection strain combination and compared with DA and BN liver isograft recipients. In the liver allografts, T-cell infiltration first occurred at 2 days after transplantation and localized to the portal triads and subjacent to the terminal hepatic venules (THV), regions rich in intensely Ia + spindle and dendritic-shaped interstitial cells. Double staining showed distinct 'clustering' between donor Ia-positive dendritic-shaped cells and W3/25+ infiltrating lymphocytes, or to a lesser extent, OX8+ cells. The infiltrating mononuclear cells underwent blastogenesis and proliferated in both the triads and THV regions at 3 and 4 days. Donor Ia-positive cells were also noted in the W3/25+ periarterial lymphatic sheath and marginal zone of the recipient spleen 1 day after transplantation. The number of these cells in the spleen peaked at 3 to 4 days, but were no longer detectable by 10 to 12 days. Mitotic activity became evident in these same regions by days 3 and 4. Paracortical blastogenesis (day 2) and proliferation (days 3 and 4) were also noted in the regional lymph nodes of liver allograft recipients, but no donor Ia+ cells were found in the mesenteric nodes or thymus of the allograft recipients. These results demonstrate that sensitization of the recipient lymphoid tissue to liver allografts can occur both peripherally (intragraft) and centrally (spleen and lymph nodes). Passenger leukocytes (donor dendritic cells) are likely the primary stimulators of the rejection reaction. Still, it is probable that other pathways of sensitization exist.

FK 506 prevents spontaneous diabetes in the BB rat

The BB rat is the experimental analogue of human juvenile diabetes mellitus. From 30 through 120 days after birth, 59 BB rats were treated with water (n = 20), or FK 506 in daily intragastric doses of 1 mg/kg (n = 19) or 2 mg/kg (n = 20). Diabetes developed in 75%, 15%, and 0% of the three groups. Animals protected from diabetes by FK 506, and killed in the nondiabetic state at 120 days had normal intraperitoneal glucose tolerance tests, virtual absence histopathologically of autoimmune insulitis, normal pancreatic insulin content, and immunocytochemical confirmation of islet insulin and glucagon content. Forty five to 75 days after stopping FK 506, about 3/4 of the animals who were diabetes free at 120 days have remained so. These results provide support for a clinical trial of FK 506 for recent onset diabetes.

Effect of FK 506 on spontaneous diabetes in BB rats

From days 30-120 after birth, 59 BB rats were treated with water (n = 20) or FK 506 in intragastric doses of 1 mg.kg-1.day-1 (n = 19) or 2 mg.kg-1.day-1 (n = 20). Diabetes developed in 75, 15, and 0% of the 3 groups, respectively. Animals protected from diabetes by FK 506 had normal intraperitoneal glucose tolerance tests, virtual absence histopathologically of autoimmune insulitis, and normal pancreatic insulin content. Forty-five to 75 days after stopping FK 506, approximately 75% of the rats that were diabetes free at 120 days remained so.

FK506 suppression of heart and liver allograft rejection. II: The induction of graft acceptance in rats

Lewis recipients of orthotopic ACI livers had permanent graft acceptance induced with 3 doses of i.m. FK506 in the early postoperative period. They were studied 100 and 300 days posttransplantation. The recipients rejected ACI as well as Brown Norway (BN) (third-party) skin grafts, and had lymphocytes with substantial reactivity by mixed lymphocyte culture testing against ACI and third-party (BN) alloantigens. Lymphocyte subset redistribution had not occurred in the peripheral blood or spleens of these animals, and there was no evidence of suppressor cell activation by in vitro and in vivo tests. Graft-versus-host reactivity in splenic lymphoid tissues of these recipients was demonstrated with the popliteal lymph node assay. Attempts at adaptive transfer with recipient lymphocytes were unsuccessful. Heart graft acceptance was far more difficult to accomplish than liver graft acceptance, and probably was never permanent. ACI heart graft prolongation in LEW recipients after a brief induction with FK506 lasted for no more than 3 months in most animals. The temporary heart graft acceptance was specific for hearts of the original ACI donor strain but not for ACI skin. Results of studies of lymphocyte subsets and suppressor cell activity were similar to those in the liver recipients. These studies illustrate how poorly graft acceptance is understood and how badly further work is needed to clarify its mechanism.

Rejection of multivisceral allografts in rats: a sequential analysis with comparison to isolated orthotopic small-bowel and liver grafts

Multivisceral isografts and allografts were transplanted to Lewis rats, and the histopathologic changes were studied in the liver, intestine, and other constituent organs. Rats receiving isografts had indefinite survival with maintenance of weight. With multivisceral allografts (from Brown-Norway donors), the intestinal component was rejected more severely than the companion liver and with about the same severity as when intestinal transplantation was performed alone. Intestinal rejection in either circumstance was a lethal event, causing death in 10 to 12 days. The earliest (by day 4) and most intense cellular rejection was in the Peyer's patches and mesenteric lymph nodes. This was associated with or followed by cryptitis, epithelial cell necrosis, focal abscess formation, mural necrosis, and eventual perforation. Liver allografts transplanted alone or as part of multivisceral grafts also had histopathologic evidence of rejection, but this was self-limiting and spontaneously reversible when the liver was transplanted alone. Thus the Achille's heel of multivisceral grafts is the intestinal component that is not protected by the presence of the liver in the organ complex. Better immunosuppression should permit successful experimental and clinical transplantation of such grafts.

Suppression of allograft rejection with FK506. I. Prolonged cardiac and liver survival in rats following short-course therapy

Heterotopic heart and orthotopic liver grafts from ACI donors were transplanted to Lewis rat recipients that were treated with a 3 (or 4) day course of FK506 IM that was started on postoperative day 0, 2, 3, 4, 5, or 6. Hearts, which rejected after a median of 6 days in untreated controls, always had prolonged survival (median 91 days) when treatment was started on postoperative day 4. The results were inferior when treatment was started earlier or later than this, but even when the first dose of FK506 was on postoperative day 5, one day before rejection was imminent in controls, the median survival was 50 days. The poorest results with a median graft survival of only 36 days were obtained when injections were on days 0-3. Results were similar with liver grafts that rejected after a median time of 10 days in nontreated controls but that usually survived permanently after a 3 (or 4) day FK506 course starting on day 0, 2, 3, or 4. Therapy started on day 6 was too late.

Orthotopic liver transplantation and the cytosolic estrogen-androgen receptor status of the liver: the influence of the sex of the donor

Mammalian liver is known to contain cytosolic receptors for both estrogens and androgens. Furthermore, certain mammalian hepatic functions are known to display a sexual dimorphism. However, in clinical liver transplantation, the sex of the donor is not taken into consideration in selection of the donor. In this study, the effect of liver transplantation on the estrogen and androgen receptor content of the liver was determined. Adult male and female rats were subjected to orthotopic liver transplantation, using donors from both the same and the opposite sex as the recipient. The animals were killed on the tenth postoperative day, and the livers were assayed to determine their cytosolic estrogen and androgen receptor content. Transplantation of a liver from a male donor into a male recipient, from a male donor into female recipient and from a female donor into a male recipient produced similar changes in the number of cytosolic estrogen and androgen receptors in hepatic cytosol. In all three situations, the estrogen receptor content in the cytosol of the transplanted liver was the same as that found in an unoperated male liver, and the cytosolic content of the androgen receptor was the same as that of an unoperated female liver. After transplantation of the liver from a female donor into a female recipient, the estrogen and androgen receptor content in the cytosol of the transplanted liver was the same as that of an unoperated female.(ABSTRACT TRUNCATED AT 250 WORDS)

Salt precipitation during the freeze-concentration of phosphate buffer solutions

Salt precipitation during the freeze concentration of phosphate solutions was investigated by differential scanning calorimetry (DSC), in view of its practical importance in the cryopreservation or freeze-drying of biological materials. It was found that the fraction of salt precipitated depends on the initial salt concentration; it began to decrease with decreasing concentration at approx. 1 M. Salt precipitation also depends on the cooling rate. In some cases, cooling at approx. 10(3) degree min-1 inhibited salt precipitation which had been observed during slow cooling (0.62 degree min-1), without, however, affecting the shape of the ice melting endotherm. In the case of ternary phosphate buffers, the fraction of salt precipitating depends on the salt composition as well as the initial concentration and cooling rate. Near the composition of the ternary eutectic or the composition where two salts are present at the same concentration, salts were prevented from precipitation.

Immunohistochemical demonstration of lysozyme and lactoferrin in salivary pleomorphic adenomas

Immunohistochemical identification of lysozyme and lactoferrin was made in salivary pleomorphic adenomas (147 cases) and the staining patterns were evaluated with respect to the histological features and histogenesis. In normal salivary glands, the intercalated duct cells gave positive staining for lysozyme in major glands, and serous acinar cells, demilune cells, and interlobular duct cells were positive in minor glands. Lactoferrin staining was irregularly positive in serous cells and ductal epithelium. In pleomorphic adenomas, the reaction for lysozyme was positive in 14% (21/147) of the cases, and was confined to luminal cells of tubulo-ductal structures. Lactoferrin in pleomorphic adenomas was distributed in luminal tumor cells (51%; 75/147), in outer tumor cells (3%; 4/147), and in both luminal and outer tumor cells (5%; 7/147) in tubulo-ductal structures; it was also detected in plasmacytoid myoepithelial cells (5%, 8/147). However, modified myoepithelial cells and other types of neoplastic myoepithelial participants were negative for lactoferrin staining. The occurrence of both lysozyme and lactoferrin in salivary pleomorphic adenomas suggests their participation in the local defense mechanism in the tumor.

Nuclear magnetic relaxation studies of the compartmentalized water in crosslinked polymer gels

Nuclear magnetic relaxation measurements of water in gels made of crosslinked dextran or polyacrylamide (water content, 30-60 wt%) were carried out using broad-line proton-pulsed NMR. Both T1 and T2 values showed inflection against pore size, i.e., the size of the compartment made by crosslinks of the polymer gels. T2 (or T1) values obtained for gels with compartments smaller than the critical size remained low within the range of the water content used in this experiment. Those values of gels with larger compartments, on the other hand, became higher with increasing size. When the size of the compartment was larger than the critical size, T1 and T2 values also became higher with increasing water content. The inflection point can be considered to correspond to the critical compartment size below which the motion of compartmentalized water in gels is more or less restricted. When the compartment is small, however, not only the effect of the molecular motion of water but also that of the proton exchange between compartmentalized water and gel matrix or hydration water should be taken into consideration for the interpretation of the short relaxation times observed, especially by T2. The results obtained in this investigation might provide useful information in the explanation and evaluation of the relaxation values in tissue.

Effect of 15-deoxyspergualin on experimental organ transplantation

DSPG had a definite but relatively feeble immunosuppressive effect in rats undergoing heterotopic heart transplantation and in dogs after renal transplantation. The drug was toxic in both species, although less so in rats. In dogs, synergistic interactions with cyclosporine and steroids were not evident.

Effect of FK506 in experimental organ transplantation

FK506 is the most potent immunosuppressive agent known. Its toxicity is substantial in dogs, minor in rats, and unknown in subhuman primates. In small doses that are nontoxic even in dogs, it can be used in synergistic combination with cyclosporine, steroids, and presumably in other drugs.

Heterotopic heart transplantation in the rat receiving FK-506 alone or with cyclosporine

In rats, FK significantly prolonged heterotopic heart graft survival over a wide dose range when given for 2 weeks starting on the day of the operation. Brief courses of FK for one to four days preoperatively, and especially beginning four days postoperatively, allowed long subsequent survival of heart grafts in otherwise untreated recipients. The seeming acceptance of the grafts with postoperative FK treatment was largely but not exclusively donor specific when tested eight days after the last FK dose by second grafts from the same donor v third-party donor grafts. FK in minimally therapeutic doses was synergistic with suboptimal doses of CyA.

THE IMMUNOSUPPRESSIVE EFFECTS OF FR 900506 IN RATS RECEIVING HETEROTOPIC CARDIAC ALLOGRAFTS

The immunosuppressive effects of FR 900506 were studied in Lewis rats given ACI heterotopic heart allografts. Intramuscular doses of 0.02 mg/kg daily for 2 weeks extended graft survival slightly, and with doses up to 1.28 mg/kg for 2 weeks, there is long-term graft survival. If only 3 daily doses were given starting on day 4 after transplantation, graft survival for almost 3 months was accomplished in 4 of 6 animals who still bear functioning hearts.

Carcinoembryonic antigen in mucoceles of oral mucosa

Immunohistochemical detection of carcinoembryonic antigen (CEA) was reported in mucocele and associated minor salivary glands of oral mucosa. Higher levels of staining for CEA occurred in salivary glands with attached mucoceles, in which acinar cells and ductal segments in the gland displayed concentrations of CEA higher than those in normal minor salivary glands. Floating cells also gave positive CEA staining, whereas epithelial fragments and connective tissue in the mucocele wall were lacking in CEA. It was suggested that mucoceles in oral mucosa accumulated CEA in associated minor salivary glands.

Keratin proteins identified in epithelial fragments of salivary mucoceles

Immunohistochemically detected keratin proteins in mucoceles of oral mucosa were used to served as markers to identify epithelial-derived cells of minor salivary glands. Normal ducts of minor salivary glands showed an intense keratin staining. Epithelial lining and or epithelial fragments in cystic walls of mucoceles displayed a strong reaction to keratin proteins too, whereas granulation tissue or connective tissue fibers of the walls were not seen. Foamy macrophages present in cystic cavities signify higher staining with the use of keratin proteins. Mucoceles in oral minor salivary glands are probably caused by ductal obstructions leading to continuous mucous secretion. Keratin proteins were used as an epithelial marker of ductal segments.

Heterogeneity of keratin distribution in the oral mucosa and skin of mammals as determined using monoclonal antibodies

The immunohistochemical localization of keratins in the oral epithelia of several mammals was investigated using the monoclonal antibodies to keratins, PKK1 (41-56 kilodaltons) and KL1 (55-57 kilodaltons). The staining patterns obtained in different locations of the oral mucosa and of the skin epidermis were compared. In the papillae on the dorsal surface of the tongue, some areas exhibited marked PKK1 staining, while other area were PKK1 negative. In general, rodent oral epithelia were negative for PKK1 in the basal layer, while comparatively strong PKK1 staining was observed in cells of the upper spinous layer. In the epidermis, positive PKK1 reactions were confined to the basal layer, while KL1 staining was occasionally seen in the basal layer of oral epithelia. In cats, dogs, and monkeys, different PKK1 and KL1 binding patterns were observed in oral epithelia. Also, the distribution in oral epithelia differed from that seen in the epidermis of these animals. In the epidermis, the distribution of PKK1 and KL1 was regular, with PKK1 usually being confined to the basal layer, while KL1 binding was found in the spinous and granular cell layers, and was dependent on the degree of keratinization. In the animals studies, keratin expression--as detected by PKK1 and KL1--was different in the skin epidermis and oral epithelia, and the localization of these keratins differed in the various types of oral mucosa.

Comparison of lectin binding patterns in salivary glands of mice and rats with special reference to different fixatives used

Lectin binding patterns in the salivary glands of mice and rats were compared among specimens treated with 9 kinds of fixatives and then individually subjected to 10 kinds of lectin staining. Formalin-fixed sections showed positive lectin binding with fine granular materials in the GCT cells, and alcohol- or acetone-fixed sections revealed vacuolated patterns of irregular lectin binding with insufficient morphologic detail. Bouin's, Helly's, and Zamboni's fixatives displayed an adequate distribution of lectin binding which corresponded to the histological aspects. Different lectins gave different characteristic binding patterns in SMGs of mice; i.e., PNA and SBA binding was positive in female GCT cells, but absent in the male. On the contrary these lectins gave positive binding in the male acinar cells but negative in the female. These contradictory results were obtained for PNA and SBA binding between the GCT cells and acinar compartments of the mouse SMGs. The GCT and acinar cells in the SMGs of mice and rats also gave contradictory results; i.e., mice GCT cells displayed positive Con A staining but negative PA/Con A staining, whereas mice acinar cells were stained weakly by the Con A and staining strongly by the PA/Con A methods. Rats GCT cells indicated negative Con A, and strong PA/Con A staining; whereas rats acinar cells gave a positive Con A and negative PA/Con A reaction.

Immunohistochemical localization of keratin in experimental carcinoma of the mouse submandibular gland

An immunohistochemical survey of the distribution of keratin was studied in chemically induced carcinomas of the submandibular glands of mice. Initial signs of premalignant changes were degranulation of granular convoluted tubule cells and deposition of keratin protein in small limited areas of the degranulated cells. There was a gradual increase in the area showing keratin staining in altered tubule cells. Duct-like and cystic structures stained intensely for keratin, as did squamous metaplastic epithelial cells. Induced carcinomas were variably keratinized. Basal layers of cells of squamous-cell carcinomas displayed weak keratin staining, and spinous tumor cells and parakeratotic tumor cells showed somewhat increased levels of keratin staining. Some desquamated keratotic tumor cells stained intensely for keratin. Just as the localization of epidermal and nerve growth factors and lectin-binding histochemistry have been used in studying tumorigenesis in the mouse submandibular gland, immunohistochemically detected keratin proved to be a useful marker of tumor cells of ductal segment origin.

Structural studies of lipophorin in insect blood by differential scanning calorimetry and 13C nuclear magnetic relaxation measurements. Location of hydrocarbons

The possible structure of lipophorin in insect blood (hemolymph) was investigated by differential scanning calorimetry (DSC) and 13C nuclear magnetic relaxation studies. The DSC heating curves of intact lipophorins showed endothermic peaks between -3 and 40 degrees C for lipophorins which contain hydrocarbons, whereas no such peaks were observed for lipophorins which do not contain this lipid. Hydrocarbon fractions isolated from the lipophorins showed endothermic peaks similar to those obtained from intact lipophorin in terms of the transition temperatures, the shapes, and the enthalpy changes. 13C spin lattice relaxation times of the (CH2)n resonance of hydrocarbons of intact lipophorin were measured as a function of temperature and revealed that the motions of hydrocarbon chains changed coincidentally with the onset and offset of phase transition. These data suggest the presence of a hydrocarbon-rich region within the lipophorin particles.

Immunohistochemical localization of alpha 1-antitrypsin and alpha 1-antichymotrypsin in salivary pleomorphic adenomas

Immunohistochemical identification of alpha 1-antitrypsin (alpha 1-AT) and alpha 1-antichymotrypsin (alpha 1-ACh) in pleomorphic adenomas of salivary glands is reported in order to compare their distribution profiles with those of lysozyme and lactoferrin, already described elsewhere. Normal salivary glands indicated positive alpha 1-AT staining in ductal segments and had no alpha 1-ACh in any glandular cell. Pleomorphic adenomas displayed moderate positivity to alpha 1-AT staining in duct-like, tubular and glandular epithelia which was particularly intense in luminal cells. The limited number of tumour cells which showed duct-like structures with a single cellular layer arrangement, displayed the highest staining to alpha 1-ACh. Strongly alpha 1-AT positive tumour cells located on the inner side of luminal cavities were also markedly positive to alpha 1-ACh. Spindle shaped tumour cells existed outside tubular and ductal structures and were negative to alpha 1-AT and alpha 1-ACh. Distribution of alpha 1-AT in salivary glands was similar to that of lysozyme as is usual in ductal segments or their transformed cells, and occurrence of alpha 1-ACh localization rather resembled that of lactoferrin, with occurrence in acinar compartments and changed epithelia within acini. The biological role of a specific immunohistochemical distribution of alpha 1-AT and alpha 1-ACh in pleomorphic adenomas may be associated with a self regulating mechanism which inhibits degradation by tissue proteinases.

Immunohistochemical evaluation of factor VIII related antigen, filament proteins and lectin binding in haemangiomas

Immunohistochemical identification of factor VIII related antigen (F VIII RAG) filament proteins (actin, myosin, filamin, vimentin and desmin) and lectin binding patterns of Con A, PNA, SBA, WGA, RCA-1, UEA-1 and DBA in the endothelial cells and the muscular layers of haemangiomas and normal blood vessels are reported, using paraffin sections with the HRP method. The endothelial cells of haemangiomas were usually strongly positive to F VIII RAG as were those from capillary vessels and other small vessels. Some of the endothelium from haemangiomas and angiokeratomas was negative for factor VIII. The vessel walls of hemangiomas showed staining slightly positive for microfilaments (actin, myosin, filamin). The smooth muscle layer in small vessels showed a more marked staining with actin. Vimentin and desmin reactions in the vessel walls of haemangioma and in normal vessels were slight or moderate. UEA-1 lectin binding was constantly positive in endothelial cells from hemangiomas and in blood vessels. SBA and WGA binding appeared in the border layer of endothelium in haemangiomas and normal vessels.

Differential distribution of immunohistochemically detected keratin proteins in mammalian oral epithelia

Keratin proteins were immunohistochemically demonstrated in different parts of the oral epithelium. Keratin staining in the squamous-cell epithelium was restricted to the spinous and granular cell layers, with a comparatively low reaction in the basal layer cells and none in the superficial cornified layer. In comparing the keratin staining levels, those in the buccal and sublingual epithelia were rather higher than those in the hard palatal epithelia. Staining intensities for keratin proteins were not the same in either different locations of the oral epithelium or in the same location in different animals.

Keratin distribution in precancerous stages of experimental carcinogenesis in mouse submandibular glands

The immunohistochemical distribution of keratin is reported in experimental carcinogenesis in the mouse submandibular gland (SMG). The initial changes included degranulation of granular convoluted tubule (GCT) cells and the appearance of keratin in the degranulated cells. There was a gradual increase in the area showing keratin staining in the altered tubule cells. Duct-like and cystic structures exhibited an intense keratin staining of their lining epithelium. The squamous cell carcinomas induced varying degrees of keratinization and positive immunohistochemical keratin staining. The latter technique provided a useful marker for distinguishing tumor cells of segmental duct origin in the salivary gland.

Histochemical observations of lectin-binding in experimental carcinomas in mouse submandibular glands

Peroxidase-conjugated lectins were used for the histochemical detection of carbohydrates in experimental carcinomas of mouse submandibular glands. Induced carcinomas, 43 lesions from 25 cases, were examined histochemically with galactose-binding lectins (PNA and RCA-1), N-acetyl-galactosamine-binding lectins (DBA and SBA), a fucose-binding lectin (UEA-1), and a N-acetyl-glucosamine-binding lectin (WGA). In non- or slightly keratinized squamous-cell carcinomas, the lectin binding of PNA, RCA-1, DBA, SBA, and WGA was weak in tumor epithelia, and UEA-1 binding was slight. In highly keratinized squamous-cell carcinomas, lectin binding was increased in tumor epithelia, but no reaction was noted in completely keratinized regions. Desquamated materials in lumens of tumors gave an intense stain with lectins. Stromal connective tissue, including collagen fibers and basement membranes stained intensely. Lectin binding to submandibular carcinomas was different from binding to granular convoluted tubules and the striated ducts of the normal submandibular gland.

Lectin-binding in premalignant lesions during submandibular gland carcinogenesis

Complex carbohydrates in premalignant lesions of mouse submandibular gland tumors were examined by the lectin-peroxidase conjugate method. Peroxidase-conjugated lectins of PNA, RCA-1, DBA, SBA, UEA-1 and WGA were used to detect specific sugar residues of complex carbohydrates in premalignant lesions during experimental carcinogenesis. Marked reduction of PNA and SBA bindings occurred in duct-like structures and cystic lesions which were transformed from granular convoluted tubule cells. Premalignant lesions bound slightly to PNA, RCA-1, DBA, SBA and WGA and manifested increased UEA-1 binding. Squamous metaplastic epithelia of premalignant lesions manifested increased binding to PNA, RCA-1 and SBA as compared to those of duct-like structure and cystic epithelia.

Histopathologic studies of DMBA-induced mouse submandibular-gland tumors with or without cryoprobe treatment

Histopathologic observations of 9,10-dimethyl-1,2-benzanthracene (DMBA)-induced tumors in the mouse submandibular glands are reported using cryoprobe treatment. The experimental animals were divided into 2 groups; one received a carcinogen injection into the normal submandibular gland, and the other was injected with DMBA on the 14th day following cryosurgery of the gland using a -60 degrees C cryoprobe. Pathologic findings were classified as premalignant lesions or squamous-cell carcinomas with varying degrees of keratinization, fibrosarcoma and mixed carcinoma. There was also one case each of malignant pleomorphic adenoma and cystic adenoma. Tumor incidence was nearly the same in the 2 groups. Most of the carcinomas and sarcomas in the submandibular gland were induced during the 12th and 17th weeks. DMBA application during the proliferating stage which followed the cryosurgery did not enhance epithelial-tumor induction. During submandibular gland carcinogenesis, alterations in the granular convoluted tubule cells suggests they were the initial target cells undergoing malignant transformation. Squamous-cell carcinomas with varying degrees of keratinization were induced following squamous metaplasia in duct-like structures or multicystic lesions.

Histochemical studies on Concanavalin A-binding in experimental carcinoma of the mouse submandibular gland

The lectin, Concanavalin A(Con A) has been used to localize specific sugar residues (D-glucose, D-mannose and D-fructose) in premalignant lesions and squamous-cell carcinomas induced following cryosurgery of the mouse submandibular gland. The original Con A-horseradish peroxidase (HRP) technique as well as its combination with periodate oxidation and subsequent reduction by borohydrate were used to compare the epithelial elements during submandibular gland carcinogenesis. Granules in the granular convoluted tubule cells which were weakly reactive to the Con A-HRP method were not present in the premalignant duct like structures. The epithelium of premalignant lesions, duct-like structures, multicystic lesions, and squamous-cell carcinomas were positive for the cell-surface and intercellular substances; and basement membranes and stromal fibers were also positive. The results indicated that throughout malignant transformation of the ductal segments, premalignant epithelia lost Con A-HRP-staining granules and that Con A-binding patterns in induced squamous-cell carcinomas were similar to those found in squamous-cell epithelium.

Immunohistochemical demonstration of epidermal growth factor and nerve growth factor in experimental carcinogenesis in the mouse submandibular gland

Immunohistochemical demonstration of epidermal growth factor (EGF) and nerve growth factor (NGF) was made during chemical carcinogenesis in the mouse submandibular gland. The granular convoluted tubule cells in the normal male submandibular gland contained larger amounts of EGF and NGF than in the female. The initial phase and early stages in chemical carcinogenesis showed degranulation of the granular convoluted tubule cells with a marked decrease in EGF and NGF. Premalignant lesions such as duct-like structures and multicystic lesions showed variable staining for EGF and were usually negative for NGF. Material secreted into the luminal spaces revealed increased staining for EGF and NGF. Scattered tumor cells of the poorly differentiated squamous-cell carcinoma type and desquamated tumor cells contained abundant EGF, but not NGF. No positive reaction for EGF or NGF was found in the induced squamous-cell carcinoma cells.

Adsorption of liposomes by clay

The interaction between liposomes and clay was investigated. Lecithin liposomes were adsorbed by montmorillonite, and aggregation of the clay particles occurred. From studies using differential scanning calorimetry (DSC), the transition temperature (Tc) from a gel to a liquid-crystalline state of this phospholipid increased by several degrees on adsorption by the clay. Although a lecithin molecule as a whole seems to have no net charge, liposomes were considered to have been adsorbed by the clay via the choline positive charge, which occupies the outermost part of the liposome membrane, as the clay is known to be negatively charged.