Growth factor-dependent regulation of transferrin receptor in proliferating and quiescent macrophages

Transferrin receptor (TfR) expression in a population of murine macrophages was investigated during the colony-stimulating factor-1 (CSF-1)-induced proliferation and quiescence. Depletion of CSF-1 from the culture medium of bone marrow cell-derived macrophages (BMM) resulted in a simultaneous decrease in the total (cell surface + intracellular) amount of TfR and complete cessation of proliferating activity [( 3H]thymidine incorporation). The addition of CSF-1 to quiescent BMM resulted in a bimodal increase in surface TfR activity. A rapid but transient twofold increase only on the cell surface due to changes in the cycling of TfR was followed by a steady increase of total cellular TfR due to de novo synthesis. A similar transient increase in surface TfR was also induced by another hemopoietic colony-stimulating factor, GM-CSF, which is mitogenic for BMM. IL-3, which did not stimulate the clonal growth of these cells, failed to modulate surface TfR. In contrast to its effect on the cycling rate of TfR in quiescent cells, CSF-1 had little effect on the TfR distribution on proliferating BMM as well as on the J774 cells (a macrophage-like tumor cell line) despite the latter expressing high levels of CSF-1 receptor. This study showed that (i) cell surface modulation by growth factor is a function of state of cellular proliferation, and (ii) rapid changes in the cell surface distribution of TfR result from changes in its cycling rates.

Non-peptide angiotensin II receptor antagonists discriminate subtypes of 125I-angiotensin II binding sites in the rat brain

We have utilized quantitative autoradiography to define subtypes of 125I-angiotensin II (AII) binding in rat brain. AII-1 binding (displaced by DuP 753) was found in the nucleus of the solitary tract and the hypothalamus, while AII-2 binding (displaced by WL 19) was found in the thalamus and lateral septum. These results indicate that subtypes of the AII receptor are present in the brain and the AII-1 receptor subtype is present in regions consistant with the known actions of angiotensin.

The treatment of progressive non-Hodgkin's lymphoma with intensive chemoradiotherapy and autologous marrow transplantation

Intensive chemoradiotherapy, with or without additional local radiotherapy, and unpurged autologous marrow transplantation was given to 68 patients with progressive non-Hodgkin's lymphoma. Responses were attained in 44 patients (65%, 95% confidence intervals [CI], 52% to 76%), including 37 who achieved complete responses. Fifteen patients (22%, 95% C.I. 13% to 34%) remain free of disease (including 11 continuously) at a median of 5.3 (range 3.1 to 9.1) years later. Higher Karnofsky scores (P less than .01, Mann-Whitney U test) and the absence of a history of prior radiotherapy (P = .02, chi 2 test) were associated with achievement of complete plus partial responses. Higher Karnofsky scores (P less than .01, Mann-Whitney U test) and less resistant disease status at transplantation (P = .04, chi 2 test) were significant when calculations were limited to complete responses. Karnofsky scores were also associated with the probability of freedom from progression (P = .02, log-rank) for responding patients. Also, Karnofsky scores and the absence of prior radiotherapy (P less than .01 and P = .01, respectively, log-rank) were associated with improved survival. Progressive lymphoma was the chief cause of failure; progression usually occurred less than 6 months after transplantation, most often at the sites of active disease before the transplant. However, five patients (including four with high-grade non-Hodgkin's lymphoma) suffered hematogenous patterns of relapse; four of these five patients had no prior history of marrow involvement. Other causes of mortality included interstitial pneumonitis, sepsis, hemorrhage and renal failure. Intensive chemoradiotherapy and autologous marrow transplantation produces durable remissions in some patients with progressive non-Hodgkin's lymphoma. Since such therapy is more effective when given to patients with signs of less advanced disease, earlier treatment would be the simplest way to produce improved results. However, improved conditioning regimens will also be needed, and measures to reduce occult lymphoma stem cell contamination with the autograft may also be required to increase the likelihood of cure in some patients.

Comparison of the inhibitory effect of polyunsaturated fatty acids on prostaglandin synthesis. II. Fibroblasts

In a previous publication we reported that PUFAs of the n-6 and n-3 series caused significant inhibition of synthesis of both PGE2 (28.4-92.8%) and PGF2 alpha (24.4-84.0%) in the oral squamous carcinoma cell line SCC-25. In this report we describe the inhibitory effect of the same acids on PG synthesis in normal human gingival fibroblasts under the same experimental conditions. It was found that a combination of EPA + DCHA (6:4), DCHA and ALA caused significant reduction in synthesis of PGE2 (10.1-87.8%) and PGF2 alpha (14.0-54.6%) at the four dose levels studied. The rank order of potency of acids in reduction of PG synthesis was: EPA + DCHA greater than DCHA greater than EPA greater than ALA greater than LA greater than DGLA greater than GLA. The data suggest that although PUFAs are effective inhibitors of PG synthesis by gingival fibroblasts and SCC-25, the fibroblast is less susceptible to the inhibitory effect of fatty acids.

Comparison of the inhibitory effect of polyunsaturated fatty acids on prostaglandin synthesis I oral squamous carcinoma cells

Polyunsaturated fatty acids (PUFAs) have been shown to suppress the growth rate of human osteogenic sarcoma cells and to have selective cytotoxic activity against human cancer cells. The purpose of this study was to investigate the efficacy of various PUFAs on inhibition of prostaglandin (PG) synthesis by oral squamous carcinoma cells (SCC-25). A significant inhibition of PGE2 and PGF2 alpha synthesis in SCC-25 was observed by all PUFAs tested except in the case of linoleic acid (LA) at 10 microM level. At 10 microM level the rank order of inhibition of PG synthesis by PUFAs was docosahexaenoic (DHA) greater than eicosapentaenoic (EPA) + DHA greater than dihomogamma-linolenic (DGLA) greater than EPA greater than alpha-linolenic (ALA) greater than linoleic (LA). At 50, 75, 100 microM the rank order of inhibition was DGLA greater than EPA greater than EPA + DHA greater than DHA greater than ALA greater than LA.

Regulation of systemic macrophage IL-1 gene transcription: the involvement of tumor-derived macrophage growth factor, CSF-1

Previous data indicated that progressive growth of the C57BL/6J sarcoma, MCA/76-9, was associated with a systemic increase in the level of IL-1 activity in peritoneal and tumor-associated macrophages. In this paper, the hypothesis was tested that macrophage IL-1 alpha and beta gene expression was regulated by the specific macrophage growth factor, CSF-1, produced by tumor cells. The data indicated that all of the nine C57BL/6J, BALB/cJ, and C3H/HeJ sarcomas tested transcribed the CSF-1 gene. The tumor cell culture supernates induced proliferation of bone marrow cells that differentiated into macrophages. Moreover, proliferative activity of conditioned medium and the ability to induce macrophage differentiation were abrograted by neutralization with the 5A1, rat-anti-mouse monoclonal anti-CSF-1 antibody. Conditioned medium from tumor cell cultures, as well as recombinant CSF-1 and L cell-conditioned medium, induced transcription of the IL-1 alpha and beta genes, the latter being more strongly expressed. IL-1 gene transcription was not induced after neutralization of the culture supernates by the monoclonal antibody, 5A1. The overall data would support the hypothesis that the pathway in vivo leading to the increased IL-1 expression by macrophages is regulated by at least one tumor cell product, CSF-1.

A sandwich enzyme-linked immunoadsorbent assay for detection of murine macrophage colony-stimulating factor (CSF-1)

A simple three-layer sandwich enzyme-linked immunoadsorbent assay (sandwich-ELISA) has been developed for murine macrophage colony-stimulating factor-1 (CSF-1) using the two monoclonal antibodies on which we recently reported (J. Immunol. (1988) 141, 483). The anti-CSF-1 monoclonal antibodies used in this assay recognize different epitopes of the same antigen, thereby permitting the detection of low amounts of CSF-1. This assay is specific to murine CSF-1. Recombinant human macrophage colony-stimulating factor, murine GM-CSF, or IL-3, either alone or together with CSF-1, does not interfere with the assay. The advantage of this assay over other reported immunoassays for CSF-1 is that radiolabeled or large quantities of purified CSF-1 are not required. This sandwich-ELISA compares favorably with other assays in its rapidity, simplicity, and sensitivity.

Treatment of progressive Hodgkin's disease with intensive chemoradiotherapy and autologous bone marrow transplantation

Twenty-six patients with progressive Hodgkin's disease after conventional chemotherapy received intensive chemoradiotherapy and autologous bone marrow transplantation (ABMT); 19 also received additional involved-field radiotherapy. Twenty-one patients [81%, 95% confidence intervals (CI) 61% to 94%] attained complete (n = 18) or partial responses. Ten patients (38%, 95% CI 20% to 59%) are disease-free a median of 4.5 years later (range 3.5 to 7.0 years), including seven patients with continuous complete responses. The likelihood of overall response was not significantly influenced by any clinical or treatment variable examined. However, there was a trend favoring patients with higher Karnofsky scores, and higher scores were associated with attainment of complete responses (P = .06 and P = .02, respectively, Mann-Whitney U test). Both higher Karnofsky scores and shorter durations of disease before transplantation were associated with improved survival in a stepwise Cox multivariate analysis. The chief cause of failure was progression at sites previously involved with Hodgkin's disease. No patient relapsed in the marrow, and two of three patients with a history of marrow involvement with Hodgkin's disease achieved durable complete responses after transplantation. These data suggest that inadequate pretransplant conditioning, and not the reinoculation of occult tumor cells in the autologous marrow, caused most relapses. Fatal treatment-related toxicity occurred in six patients. Three patients died of idiopathic interstitial pneumonitis; each had previously received local mediastinal irradiation before intensive chemoradiotherapy. Intensive chemoradiotherapy and ABMT produces durable responses in some patients with Hodgkin's disease incurable with conventional therapy. Use of such therapies at the first sign of failure with conventional chemotherapy and development of more effective conditioning regimens should further improve results.

Purification and characterization of a benzodiazepine-like substance from mammalian brain

An endogenous brain ligand which competes with [3H]-flunitrazepam for the binding to benzodiazepine receptor has been isolated and purified to homogeneity. The purification procedures involve the extraction of the endogenous ligand by homogenizing the brain tissue in water containing various protease inhibitors followed by filtration through a PM 10 membrane (exclusion limit: 10,000-dalton), column chromatographies on Sephadex G-50, Bio-Rad P2 and a series of C18 reverse phase HPLC columns. The purified endogenous ligand was eluted as a single and symmetrical peak monitored at either 220 or 280 nm. Furthermore, the ligand activity coincided with the absorption peak. The purified endogenous ligand is thermostable, insensitive to various peptidases and proteolytic enzymes, resistant to DNAse, RNAse, and carbohydrate enzyme e.g. neuraminidase (EC 3.2.1.18) and acid treatment. It has a major absorption peak at 220 nm and a minor one at 313 nm. The endogenous ligand appears to be quite specific since it only inhibits the binding of ligand to the central type benzodiazepine receptor but not to other receptors, e.g. peripheral type benzodiazepine receptor, alpha 1-adrenoceptor, alpha 2-adrenoceptor, beta-adrenoceptor and muscarinic cholinergic receptor. Furthermore, the inhibition of the receptor binding by the endogenous ligand is enhanced by GABA suggesting that the endogenous ligand is a benzodiazepine receptor agonist. The structure of the endogenous ligand is unknown.

Both granulocyte-macrophage CSF and macrophage CSF control the proliferation and survival of the same subset of alveolar macrophages

The effect of granulocyte-macrophage (GM)-CSF on the proliferation of murine pulmonary alveolar macrophages in vitro was investigated. About 20% of freshly isolated alveolar macrophages formed colonies in both liquid and soft agar cultures in the presence of GM-CSF. GM-CSF was also found to be capable of maintaining the survival of these colony-forming cells in vitro. Moreover, GM-CSF could substitute for CSF-1 in maintaining the survival of CSF-1-responding pulmonary alveolar macrophage colony-forming cells in the absence of CSF-1. The concentration of GM-CSF required for maintaining the survival of colony-forming cells without proliferation was much lower than that required for the proliferation of these cells in vitro. It also enhanced the CSF-1-dependent clonal growth of alveolar macrophages. These data suggest that the colony-forming cells that respond to GM-CSF are the same subset of macrophages that form colonies in the presence of CSF-1. GM-CSF did not inhibit the binding of 125I-CSF-1 to alveolar macrophages at 0 degrees C. However, the preincubation of macrophages with GM-CSF at 37 degrees C resulted in a transient down-regulation of CSF-1 binding activity.

Both granulocyte-macrophage CSF and macrophage CSF control the proliferation and survival of the same subset of alveolar macrophages

The effect of granulocyte-macrophage (GM)-CSF on the proliferation of murine pulmonary alveolar macrophages in vitro was investigated. About 20% of freshly isolated alveolar macrophages formed colonies in both liquid and soft agar cultures in the presence of GM-CSF. GM-CSF was also found to be capable of maintaining the survival of these colony-forming cells in vitro. Moreover, GM-CSF could substitute for CSF-1 in maintaining the survival of CSF-1-responding pulmonary alveolar macrophage colony-forming cells in the absence of CSF-1. The concentration of GM-CSF required for maintaining the survival of colony-forming cells without proliferation was much lower than that required for the proliferation of these cells in vitro. It also enhanced the CSF-1-dependent clonal growth of alveolar macrophages. These data suggest that the colony-forming cells that respond to GM-CSF are the same subset of macrophages that form colonies in the presence of CSF-1. GM-CSF did not inhibit the binding of 125I-CSF-1 to alveolar macrophages at 0 degrees C. However, the preincubation of macrophages with GM-CSF at 37 degrees C resulted in a transient down-regulation of CSF-1 binding activity.

Unusual ultrastructural features in the superficial pineal gland of the yellow-bellied country rat (Rattus losea Swinhoe)

The ultrastructure of the superficial pineal gland of the yellow-bellied country rat (Rattus losea Swinhoe), living under natural climatic conditions at the margin of the tropical region, was studied with special reference to the seasonal changes. In the rainy season with average monthly rainfall of 400 mm (light phase of 13.5 h, and temperature of 28 degrees C) the gland was characterized by the presence of frequent large vacuoles containing flocculent material (LVFs), large condensed inclusions (LCIs) in the pinealocytes, and extensive accumulations of presumptive secretion in the extracellular compartment, suggesting an enhanced secretory activity. In the dry season with average monthly rainfall of 13 mm (light phase of 11 h, and temperature of 19 degrees C), however, the pinealocytes were characterized by the presence of numerous clear spindles, which exhibited acid phosphatase activity; at this time there were few LVFs and LCIs and rare extracellular accumulations, suggesting a declined glandular activity. We conclude that the cellular activity of the pineal gland in R. losea, living under tropical climatic conditions, is synchronized with the annual changes of rainfall, which is apparently more important than the annual changes of photoperiod and temperature.

Biochemical mechanisms underlying the development of radioresistance by cultured peritoneal exudate macrophages

We investigated changes in radiosensitivity of peritoneal exudate macrophage colony-forming cells (PE-CFC) when exudative peritoneal macrophages were cultured in vitro. The change in the shape of the dose-response curve of PE-CFC to ionizing irradiation was partly dependent on the concentration of oxygen in the gas phase of the incubators. When cells were incubated in an environment containing 20% oxygen, the value of both Dq and D0 for PE-CFC increased. The dose-response curve of PE-CFC cultured for 3 days resembled that of alveolar macrophage colony-forming cells (AL-CFC). The changes in radiosensitivity were accompanied by an increase in the level of three antioxidant enzymes: superoxide dismutase, catalase, and glutathione peroxidase. However, when they were cultured in a 6% oxygen environment, only the value of Dq increased. When alveolar macrophages were incubated in vitro, no significant change in the shape of the dose-response curve of AL-CFC was noted whether they were cultured in gas phase containing either 20 or 6% oxygen. It is concluded that the radiosensitivity of PE-CFC changes when they are cultured in vitro. The increase in D0 appears to be related to the intracellular level of antioxidant enzymes.

Development and characterization of monoclonal antibodies to murine macrophage colony-stimulating factor

The macrophage-specific CSF (CSF-1), purified from murine L cell-conditioned medium, supports the in vitro proliferation and survival of various murine mononuclear phagocyte colony-forming cells. In this report we describe the production and functional characterization of two monoclonal antibodies (mAb) to CSF-1 obtained from rat X rat hybridomas. These two mAb are functionally distinct and recognize different epitopes on CSF-1. The mAb 5A1 binds to and inhibits the biologic function of CSF-1, and the second mAb (D24) binds CSF-1 but does not neutralize its biologic activity. The mAb 5A1 inhibits colony formation of tissue mononuclear phagocyte colony-forming cells as well as the committed bone marrow stem cells for both granulocytes and monocytes. The extent of colony inhibition by mAb 5A1 is dependent on the tissue origin of colony-forming cells. CSF-1 complexed with mAb 5A1 does not bind to its cell surface receptor of peritoneal exudate macrophages, and mAb 5A1 does not complex with cell-bound CSF-1. Although both bone marrow cell-derived macrophages and J774.1 macrophages bind CSF-1, mAb 5A1 inhibits the proliferation of only bone marrow cell-derived macrophages. The non-neutralizing mAb D24 does not block binding of CSF-1 to its cellular receptor, and it recognizes cell-bound CSF-1.

Development and characterization of monoclonal antibodies to murine macrophage colony-stimulating factor

The macrophage-specific CSF (CSF-1), purified from murine L cell-conditioned medium, supports the in vitro proliferation and survival of various murine mononuclear phagocyte colony-forming cells. In this report we describe the production and functional characterization of two monoclonal antibodies (mAb) to CSF-1 obtained from rat X rat hybridomas. These two mAb are functionally distinct and recognize different epitopes on CSF-1. The mAb 5A1 binds to and inhibits the biologic function of CSF-1, and the second mAb (D24) binds CSF-1 but does not neutralize its biologic activity. The mAb 5A1 inhibits colony formation of tissue mononuclear phagocyte colony-forming cells as well as the committed bone marrow stem cells for both granulocytes and monocytes. The extent of colony inhibition by mAb 5A1 is dependent on the tissue origin of colony-forming cells. CSF-1 complexed with mAb 5A1 does not bind to its cell surface receptor of peritoneal exudate macrophages, and mAb 5A1 does not complex with cell-bound CSF-1. Although both bone marrow cell-derived macrophages and J774.1 macrophages bind CSF-1, mAb 5A1 inhibits the proliferation of only bone marrow cell-derived macrophages. The non-neutralizing mAb D24 does not block binding of CSF-1 to its cellular receptor, and it recognizes cell-bound CSF-1.

Self-renewal of pulmonary alveolar macrophages: evidence from radiation chimera studies

Radiation-induced chimeric mice were used to study the origin of pulmonary alveolar macrophages. Unlike in other studies, these radiation chimeras were prepared by using a special fractionated irradiation regimen to minimize the killing of alveolar macrophage colony-forming cells, putative local stem cells. For this study CBA mice with or without T6 chromosome marker were used. Under this experimental condition, the majority of alveolar macrophages in mitosis are of host origin even after 45 weeks. These data suggest that alveolar macrophages are a self-renewing population under normal steady-state conditions.

Prostaglandin synthesis by squamous carcinoma cells of head and neck, and its inhibition by non-steroidal anti-inflammatory drugs

The purpose of this study was to determine the nature and amounts of prostaglandins (PGs) produced by squamous carcinoma cells (SCC) and the sensitivity of these cells to non-steroidal anti-inflammatory drugs. SCC of four lines of the tongue and one line of facial epidermis of humans were incubated in phosphate buffer solution with 14C-arachidonic acid (AA). Radioactive metabolites in aqueous methanol were chromatographed on Sep-Pack C18 cartridges, separated and quantitated by means of TLC, autoradiography, and liquid scintillation counting. The results showed that cyclooxygenase products, PGs, were the major products formed by all cell lines, and PGE2 was predominant among the PGs detected. Two radioactive bands corresponding to PGF2 alpha and three unseparated standards of PGA2, 15-keto-PGE2, and 13,14-dihydro-15-keto-PGE2 were detected in lesser amounts. Very small amounts of the lipoxygenase products 12- and 15-HETE were found. The concentrations of indomethacin, ibuprofen and aspirin required to inhibit 50% of PGE2 synthesis (IC50) by SCC lines were .008-.080, .080-6.4 and 32-88 microM, respectively.

Effect of effervescent buffered aspirin on prostaglandin synthesis by human gingival fibroblasts

Cultured human gingival fibroblasts were incubated with 14C-arachidonic acid (AA) at 37 degrees C for 2 hours. The metabolites formed were extracted from the cell-free medium in methanol, separated and identified by thin layer chromatography, using two solvent systems that allowed resolution of cyclooxygenase and lipoxygenase products. The predominant cyclooxygenase products were PGE2 and 6-keto-PGF1 alpha. PGA2, PGF2 alpha, PGD2, 15-keto-PGE2, TXB2 were also detected in smaller amounts. No detectable radioactivity corresponding to lipoxygenase products 5-HETE, 12-HETE, and 15-HETE was found. Incubation of fibroblasts with effervescent buffered aspirin (EBA) (.02%, .04%, .06%), or sodium bicarbonate, citric acid and aspirin, individually, (in concentrations equivalent to those present in EBA) resulted in stimulation of synthesis of PGs except PGE2 which was inhibited by EBA and aspirin.

Three dimensional visualization of the Golgi apparatus and endoplasmic reticulum in the subcommissural organ cells with high voltage electron microscopy

Fine structure and stereo-images of the Golgi apparatus and endoplasmic reticulum (ER) in the subcommissural organ (SCO) cells were visualized by the application of zinc-iodide osmium tetroxide (ZIO) impregnation, conventional electron microscopy and high voltage electron microscopy (HVEM). The Golgi apparatus in the SCO cells of rats, gerbils and hamsters consisted of flattened saccules stacked in parallel array. It showed a selective staining toward ZIO mixture and might form a complex network of tubular structures because of the presence of numerous fenestrations in the flattened Golgi saccules. The cytoplasm of the SCO cells in the rat and gerbil was crowded by dilated cisternae of the ER with a few flattened profiles. In the hamster SCO cells, however, the dilated cisternae of the ER were not observed. Flattened cisternae of ER in all species studied showed a positivity for ZIO impregnation and formed a complex tubular network, whereas dilated cisternae of the ER in the rats and gerbils did not show any reactivity. It was thus determined that the observation of thin and thick sections selectively stained with appropriate reagent for defined cellular organelles under conventional electron microscopy and HVEM offered valuable information about three-dimensional organization of the cell. A definite species-specific variation of SCO ultrastructure and cytochemistry was also demonstrated.

Immunocytochemical identification of growth hormone cells in the adenohypophysis of the golden hamster

Somatotrophs or growth hormone (GH) cells in the adenohypophysis of golden hamsters were identified by immunocytochemical staining with polyclonal rabbit anti-human GH. They were oval or columnar in shape, and had secretory granules of two size ranges, 90-150 nm and 280-320 nm, which were present in the same cells; no subtypes of GH cells were observed. Secretory granules were located in the peripheral portion of the cytoplasm or concentrated at the vascular pole of the cell. Flattened cisternae of the rough endoplasmic reticulum in parallel array and a moderately developed Golgi apparatus were often found in the cytoplasm. No sex difference was noticed in the population ratio of GH cells. Immunocytochemical staining with anti-GH or anti-prolactin (PRL) antibodies on separate adjacent sections revealed that the GH and PRL were stored in two different cell types.

Fine structural and cytochemical studies on the hamster subcommissural organ

The subcommissural organ (SCO) of the golden hamster (Mesocricetus auratus) was studied by conventional electron microscopy, freeze-fracture technique, zinc-iodide-osmium (ZIO) and acid phosphatase cytochemical reactions. The ultrastructure of hamster SCO cells shows a few flattened cisternae of rough endoplasmic reticulum (ER) without dilated ones in the cytoplasm. The Golgi apparatus is very well developed. Freeze-fracture studies also indicate only short profiles of flattened ER in the cytoplasm endorsing the absence of dilated ER cisternae. After the treatment with ZIO mixture, reaction products were observed over flattened cisternae of the ER and the nuclear envelope. The Golgi apparatus was also reactive toward the ZIO mixture. Acid phosphatase activities are localized in the inner one or two saccules of the Golgi apparatus and dense bodies. From these results we suggest that (1) hamster SCO cells do not accumulate secretory material in the cytoplasm in the form of discrete secretory granules or dilated cisternae of ER, and (2) hamster SCO cells may possess extremely high secretory activity or may not be actively involved in secretory function at all as in rats or other rodents.

A centrosomal inclusion (striped nebulous body) in pinealocytes of the golden hamster

Electron microscopy has revealed the presence of a special cytoplasmic body in the centrosomal area of pinealocytes of the golden hamster, Mesocricetus auratus. It consists of branching electron-dense ribbons embedded in a flocculent matrix of moderate electron density, and is tentatively named the 'striped nebulous body' (SNB). The dense ribbon usually appears as a thick band accompanied by a parallel thin one to one side. The SNB is not bounded by a membrane, and is roughly round or kidney-shaped. Closely associated with the SNB are centrioles, microtubular sheaves and striated fibrils, the latter two being centriolar derivatives. The observations suggest that the SNB might be formed by the amalgamation of these microtubular sheaves and striated fibrils. In golden hamsters, pinealocytes often have multiple centrioles and centriolar derivatives. The SNB of adult hamsters is seen in the pinealocytes of both sexes, irrespective of the season of the year and the activity of the pineal gland. The functional significance of this body remains to be studied.

Immunocytochemical studies on prolactin cells in the adenohypophysis of the golden hamster

Mammotrophs or prolactin (PRL) cells were identified in the adenohypophysis of adult golden hamsters by immunocytochemical techniques with a polyclonal anti-PRL, that was proved to be specific to PRL by the dot immunoblotting test. Postembedding immunostaining was performed on Araldite thin sections by immunoperoxidase and immunogold methods. PRL cells were classified into three types according to the different size of the secretory granules. The Type A cells were usually small and angular or oval in shape, and had secretory granules ranging in diameter from 100-230 nm, and showed poorly developed organelles. The Type B and C cells were larger and round or ovoid in shape, contained larger granules, 230-280 nm and 280-570 nm, respectively, and displayed well developed organelles. Immunoreactive PRL cells in the male pituitaries were far less numerous than in the nonpregnant female glands, and were mostly of the Type A and B, whereas in the female the Type C and B cells predominated. In pregnant females, Type C cells became activated and increased in number, while the other two types decreased in proportion. In lactating females, Type A and B cells significantly increased in number at the expense of the Type C cells; meanwhile, the exocytosis of secretory granules was frequently found in all types of PRL cells. The present findings suggest that Type C and B PRL cells, especially the former, are potent in producing and releasing PRL and highly responsive to various physiological stimuli, while Type A cells are probably relatively inert in synthetic activity.

Brain L-glutamate decarboxylase: purification and subunit structure

Glutamate decarboxylase (GDCase; L-glutamate-1-carboxy-lyase, EC 4.1.1.15) was purified from whole rat brain approximately equal to 1300-fold to apparent homogeneity with a specific activity of 2.4 units per mg of protein by a combination of column chromatographies on DEAE-cellulose, hydroxylapatite, and gel filtration, and preparative nondenaturing polyacrylamide gel electrophoresis. The purified preparation contained a single protein band that comigrated with GDCase activity in three diverse analyses: nondenaturing regular (5%) and gradient (3.6-25%) polyacrylamide gel electrophoresis and isoelectric focusing at pH 4-7. The native molecular mass was calculated to be 120 +/- 10 kDa from gradient polyacrylamide gel electrophoresis and 110 +/- 10 kDa from gel filtration. Under the treatment with NaDodSO4 and 2-mercaptoethanol, GDCase dissociated into two subunits of 40 +/- 2 and 80 +/- 4 kDa, as estimated from NaDodSO4 gel electrophoresis. However, only a 40-kDa subunit was detected when GDCase was treated with 4 M urea plus NaDodSO4 and 2-mercaptoethanol, suggesting that the 80-kDa subunit is the dimer of the 40-kDa subunit. In immunoblotting, polyclonal antibodies against GDCase reacted with both 40- and 80-kDa subunits, while monoclonal antibody reacted with only 80-kDa subunits. The isoelectric point of the native enzyme was 5.4. The Km for glutamate was 1.59 X 10(-3) M. In addition to L-glutamate, cysteine sulfinic acid was also decarboxylated at approximately equal to 10% of the rate of glutamate. The pH optimum was fairly broad, with a maximum at approximately equal to 7.3. The enzyme was strongly inhibited by carbonyl-trapping agents, sulfhydryl reagents, thiol compounds, and beta-methylene-DL-aspartate.

Modulation of tissue mononuclear phagocyte clonal growth by oxygen and antioxidant enzymes

We have investigated the effects both of oxygen concentrations below that of ambient air in the gas phase and antioxidant enzymes on the clonal growth of various tissue mononuclear phagocyte colony-forming cells in vitro. The degree of enhancement in growth is dependent on the source of these colony-forming cells. Clonal growth of colony-forming cells from peritoneal exudate was enhanced both by lowering the oxygen tension and using three antioxidant enzymes (superoxide dismutase, catalase, and glutathione peroxidase). The optimal concentration of oxygen was 6%. Colony-forming cells from alveolar spaces failed to respond to either the reduction in oxygen tension or the addition of antioxidant enzymes to the culture dishes. The optimal concentration of oxygen for the clonal growth of blood monocytes was 6%. However, clonal growth was enhanced more in soft agar than in liquid culture. Our data also suggest that at least part of the growth-enhancing effect of hemolysate may be attributable to its ability to decrease oxygen toxicity.

Implications for adolescent sex education in Taiwan

This first Taiwan-wide sample survey of adolescent sexual awareness, knowledge, attitude, and behavior shows that secondary school students there: lack basic knowledge about contraception and reproduction, are often not being taught adequately about these subjects in school, have fairly permissive attitudes about sexual relationships, particularly males, are sexually active, particularly males and those in the private vocational high schools (although less so than their US counterparts), want to learn more about the nature of intimate relationships between males and females, and look to school and public health agencies to be more active sources of information and education.

Production and characterization of polyclonal and monoclonal antibodies to rat brain L-glutamate decarboxylase

Specific monoclonal and polyclonal antibodies to rat brain glutamate decarboxylase (GAD) were produced and characterized. Polyclonal antibodies against GAD were raised in rabbits by injecting a total of 70-210 micrograms of purified GAD i.m. The specificity of anti-GAD serum was established from a variety of tests including Ouchterlony immunodiffusion, immunoelectrophoresis, immunoprecipitation, dot immunoassay, ELISA tests and Western immunoblottings. In immunodiffusion and immunoelectrophoresis tests using partially purified GAD preparations and anti-GAD serum a single, sharp precipitin line corresponding to GAD activity was obtained. Quantitative immunoprecipitation of GAD activity was achieved using anti-GAD IgG and Staphylococcus aureus. Specificity of the antiserum was further indicated from a dot immunoassay and ELISA tests in which the intensity of the reaction product was proportional to the amount of GAD protein present. In the Western immunoblotting experiments using partially purified GAD preparations only two protein bands corresponding to the position of the two subunits of GAD were stained by anti-GAD IgG, further supporting the specificity of polyclonal antibodies against GAD. In addition to polyclonal antibodies, several specific GAD-antibodies-producing clones were also obtained by the hybridoma technique. The specificity of monoclonal antibodies against GAD were established from the following criteria: positive on ELISA test using homogeneous GAD as antigen; formation of GAD--anti-GAD IgG complex as indicated from gel filtration chromatography and sodium dodecyl sulfate polyacrylamide gel electrophoresis; and specific recognition of GAD subunit in a partially purified GAD preparation in Western immunoblotting test. Monoclonal antibodies were further characterized by immunohistochemical localization of known GABAergic neurons and their processes in the cerebellum and retina.

Effects of dose rate and dose fractionation of irradiation on pulmonary alveolar macrophage colony-forming cells

We have studied the effects of dose rate and dose fractionation on murine pulmonary alveolar macrophage colony-forming cells (AL-CFC). The dose-response curve of AL-CFC to ionizing irradiation has a Dq of about 100 rad, reflecting the cells' ability to repair sublethal damage. For comparison, we investigated the effect of dose schedule on the committed bone marrow stem cells for both granulocytes and monocytes (GM-CFC) since their dose-response curve has a very small shoulder. We compared the results of dose rates of 3 and 10 rad/min to those obtained with a dose rate of 85 rad/min. We determined survival after giving 100, 300, and 500 rad either in vivo or in vitro. A significant dose rate effect was observed. To study the effect of dose fractionation, a total of 600 rad was given either as a single fraction, three fractions of 200 rad on 3 consecutive days, or six fractions of 100 rad in 3 days. The most dramatic effect was seen in the group that received six 100-rad fractions. No reduction in the number of AL-CFC was seen in this group. In sharp contrast, only a minimal dose schedule effect was observed with GM-CFC.

Biosynthesis of prostaglandins and hydroxy fatty acids in primary squamous carcinomas of head and neck in humans

The metabolism of [14C]arachidonic acid into cyclooxygenase and lipoxygenase products by homogenates of primary squamous carcinomas of head and neck in 12 patients was studied in vitro. The lipoxygenase pathway was predominant in all samples. The major metabolites were 12-hydroxy-5,8,11-14-eicosatetraenoic acid, (12-HETE) and 15-HETE. 5-HETE, 5,12-diHETE, 8-HETE and 9-HETE were also detected. The cyclooxygenase products detected were in the following order: PGE2 greater than PGF2 alpha greater than TxB2 greater than 15-keto-PGE2 greater than 6-keto-PGF1 alpha greater than PGD2. Literature review of the biological activities of these oxygenated metabolites of arachidonic acid suggest important modulatory roles in the pathophysiology of head and neck cancer.

Arachidonic acid metabolism in inflamed gingiva and its inhibition by anti-inflammatory drugs

Prostaglandin (PG) synthetase inhibitors are tissue-selective. Therefore, the action of four nonsteroidal anti-inflammatory drugs (NSAID) was tested against PG synthesis from 14C-arachidonic acid by gingival homogenate. Suprofen and tolmetin sodium did not significantly inhibit PGs at any of the three concentration levels used (10(-7), 10(-5), 10(-3) M), whereas flurbiprofen and zomepirac sodium did significantly inhibit PG formation at millimolar concentration. The results, coupled with our previous study on indomethacin, piroxicam and ibuprofen open the way for future tests of NSAIDs in treatment of gingival inflammation and periodontal disease.

Receptor-mediated binding and internalization of colony-stimulating factor (CSF-1) by mouse peritoneal exudate macrophages

Colony-stimulating factor (CSF-1) purified from L-cell-conditioned medium is a haemopoietic growth factor that specifically stimulates the proliferation and differentiation of mononuclear phagocytes. Using radioactively labelled CSF-1 [(125I]CSF-1), the presence of specific CSF-1 receptor has been identified in the cells of the mononuclear phagocytic series and their precursors only. To determine the fate of [125I]CSF-1 bound to peritoneal exudate macrophages (PEM) at 37 degrees C, we have examined the distribution of radioactivity as a function of time by quantitative electron microscopic autoradiography. At 0 degrees C, we have localized the initial step in the binding of [125I]CSF-1 to the plasma membrane and its invaginations of the mouse PEM. Approximately 16% of the macrophages were not labelled at this time point. When the temperature was raised to 37 degrees C, the labelled CSF-1 was internalized progressively by the cells in a time-dependent fashion. The proportion of grains associated with the phagolysosome compartment increased progressively, reaching a plateau by 40 min after warming up, while the relative areas of the surface membrane and its invaginations decreased in invaginated membrane. At 37 degrees C, incubation with unlabelled CSF-1 resulted in a “down-regulation' of the subsequent [125I]CSF-1-binding activity by PEM in a time- and dose-dependent fashion. The restoration of CSF-1-binding activity after CSF-1 induced down-regulation was inhibited by cycloheximide, a potent protein synthesis inhibitor. These data provide direct evidence that at 37 degrees C, saturable binding of CSF-1 to PEM is followed by internalization and cellular degradation of the ligand and possibly its receptor by phagolysosomes.

Colony-stimulating factor (CSF-1): its enhancement of plasminogen activator production and inhibition of cell growth in a mouse macrophage cell line

CSF-1 is a hemopoietic growth factor that specifically causes the proliferation and differentiation of mononuclear phagocytic cells. J774 cells are a monocyte precursor-like macrophage cell line. This transformed macrophage cell line exhibits specific 125I-CSF-I-binding activity similar to that of normal murine macrophages, although its survival and growth is independent of CSF-1. At 0 degrees C, saturation of binding sites was achieved at 240 pM 125I-CSF-1. At 37 degrees C, the bound 125I-CSF-1 was rapidly internalized and degraded by the target cells with a T1/2 of approximately 30 min; degradation was inhibited by the addition of NH4Cl. The addition of CSF-1 to cultures caused dose-dependent inhibition rather than stimulation of [3H]thymidine uptake by J774 cells. Whereas CSF-1 stimulated the clonal growth of normal mouse peritoneal exudate macrophages, it inhibited the clonal growth of J774 cells in agar cultures. Furthermore, CSF-1 exhibited a concentration-dependent enhancement of the production of plasminogen activator (PA) by J774 cells. The enhanced production of PA was detected 6 hr after the addition of CSF-1 and was inhibited by the simultaneous addition of the anti-inflammatory drug. It appears that the effects of CSF-1 on cell proliferation and PA production by CSF-1 receptor-bearing cells are mediated by distinct intracellular pathways albeit through the same receptor.

Colony-stimulating factor (CSF-1): its enhancement of plasminogen activator production and inhibition of cell growth in a mouse macrophage cell line

CSF-1 is a hemopoietic growth factor that specifically causes the proliferation and differentiation of mononuclear phagocytic cells. J774 cells are a monocyte precursor-like macrophage cell line. This transformed macrophage cell line exhibits specific 125I-CSF-I-binding activity similar to that of normal murine macrophages, although its survival and growth is independent of CSF-1. At 0 degrees C, saturation of binding sites was achieved at 240 pM 125I-CSF-1. At 37 degrees C, the bound 125I-CSF-1 was rapidly internalized and degraded by the target cells with a T1/2 of approximately 30 min; degradation was inhibited by the addition of NH4Cl. The addition of CSF-1 to cultures caused dose-dependent inhibition rather than stimulation of [3H]thymidine uptake by J774 cells. Whereas CSF-1 stimulated the clonal growth of normal mouse peritoneal exudate macrophages, it inhibited the clonal growth of J774 cells in agar cultures. Furthermore, CSF-1 exhibited a concentration-dependent enhancement of the production of plasminogen activator (PA) by J774 cells. The enhanced production of PA was detected 6 hr after the addition of CSF-1 and was inhibited by the simultaneous addition of the anti-inflammatory drug. It appears that the effects of CSF-1 on cell proliferation and PA production by CSF-1 receptor-bearing cells are mediated by distinct intracellular pathways albeit through the same receptor.

Synaptic junctions between the adrenergic axon varicosity and the pinealocyte in the rat

Intercellular relationships of sympathetic nerve fibers and cells in pineal glands of Long-Evans rats and yellow-bellied country rats (Rattus losea Swinhoe) were studied with conventional electron microscopy. Typical synapses were found between adrenergic axon varicosities and pinealocytes. The synaptic cleft was 20-30 nm thick and contained granular or filamentous material of moderate electron density. Some small granulated vesicles attached to, or fused with, the presynaptic axolemma, a feature suggesting an exocytotic release of the vesicle content. The occurrence of membranous cisternae or tubules in the synaptic nerve ending may connote the phenomenon of synaptic vesicle recycling. Beneath the postsynaptic pinealocyte plasmalemma there was a dense plaque corresponding to the postsynaptic density of neurons. Possible origins and functional significance of the synapse-making nerve fibers are also discussed.

Pharmacokinetic profile of a new anticonvulsant, stiripentol, in the rhesus monkey

Stiripentol is a new anticonvulsant drug derived from phenyl-l-pentene-ol. One of its metabolites resulting from opening of the methylenedioxy ring also possesses anticonvulsant activity. This study undertook to define the overall pharmacokinetic profile of stiripentol in rhesus monkey prior to its efficacy evaluation. The experimental design included six treatments (three intravenous doses of 40, 80, and 120 mg; one oral dose of 80 mg; and two intraperitoneal doses of 80 and 120 mg) administered to five chaired rhesus monkeys in a randomized fashion. Sixteen plasma samples were obtained over 7 h and urine was collected for 24 h. A high-performance liquid chromatography assay was developed for the determination of stiripentol in plasma and urine (C8 reverse phase column and UV detection, lambda = 254 nm). The intravenous data revealed multiexponential behavior and therefore noncompartmental methods were used to describe the pharmacokinetics of stiripentol. Values for plasma clearances (L/h/kg) were 1.10 +/- 0.07 (40 mg), 0.92 +/- 0.08 (80 mg), and 0.86 +/- 0.15 (120 mg). The decrease in clearance with dose provided evidence of nonlinearity. The average mean residence time was 1.09 +/- 0.03 h. The average volume of distribution at steady state was 1.03 +/- 0.3 L/kg. The bioavailabilities obtained for the oral and intraperitoneal doses were consistent with first-pass effect predictions: 0.3 (oral), 0.32 (i.p. 80 mg), and 0.34 (i.p. 120 mg). The free fraction determined by equilibrium dialysis was less than 1%. The fraction of dose excreted unchanged in urine ranged between 0 and 3%. The metabolite with anticonvulsant activity could not be detected in plasma with any of the modes of administration. However, it was found in urine and accounted for 2% of the dose. The fraction metabolized by glucuronidation was 34.8 +/- 9.1%. The percentages of total amount of glucuronide excreted in the intervals 0-2, 2-4, 4-8, and 8-24 h were 70.6 +/- 6.2, 10.1 +/- 5.4, 13.6 +/- 5.1, and 5.7 +/- 3.1%. These findings suggested that the terminal phase was not associated with elimination but rather with drug distribution.

Pharmacokinetics of stiripentol in normal man: evidence of nonlinearity

The pharmacokinetics and metabolism of stiripentol, a new antiepileptic drug, were investigated in normal male subjects after single-dose and multiple-dose administration. Each of six subjects received single doses of 300, 600, and 1200 mg of stiripentol in powder form and another 600 mg in solution. In the multiple-dose study, each of six subjects received a 300-mg dose on day 1 and multiple doses (1200 mg/day) from day 2 to day 8. Five of these six subjects participated also in the single-dose study. Stiripentol and several of its metabolites, namely, stiripentol conjugate, DiOH, P-OH, and M-OH, were analyzed in plasma and urine. After single doses, the elimination curve of stiripentol appeared multiphasic. The oral clearance was 1.3 to 1.8 liter/hr/kg. The average mean residence time was 4 hours. There were no statistically significant differences in clearance or mean residence time among the three doses. However, dose dependence was found in all the four pathways when formation clearances were compared. Only trace amounts of the drug were excreted unchanged in urine. The active metabolite, P-OH, was not detectable in plasma. Stiripentol was very highly bound to plasma proteins in plasma from dosed subjects as well as spiked human plasma (free fraction of 1 per cent). In the multiple-dose study, there was a decrease (nearly eightfold) in oral clearance of stiripentol between day 1 and day 8. The fractions of dose metabolized through conjugation and methylenedioxy ring opening increased 183 and 49 per cent, respectively, but the formation clearances for all the pathways were decreased. These findings suggest that the steady-state plasma level/dose ratio of stiripentol will increase with the daily dose.

The effect of non-steroidal anti-inflammatory drugs on the metabolism of 14C-arachidonic acid by human gingival tissue in vitro

We investigated the effect of non-steroidal anti-inflammatory drugs on prostaglandins (PGs) and 12-hydroxyeicosatetraenoic acid (12-HETE) formation by inflamed human gingival tissues. Gingival tissue homogenates were incubated with 14C-arachidonic acid in the presence of indomethacin, piroxicam, or ibuprofen, and the organic solvent extracts were chromatographed on silica gel plates with standards for radiometric assay. There was a significant negative trend between the doses (10(-7)-10(-3) M) of each of indomethacin, piroxicam, and ibuprofen, and the amounts of PGF2 alpha, PGE2, PGD2, and 15-keto-PGE2 produced. All three drugs have a significant inhibitory effect on PGs and 12-HETE production at 10(-3) M when compared with the control. The rank order effectiveness of the drugs, at 10(-3) M, on PG inhibition was indomethacin greater than piroxicam greater than ibuprofen, and on 12-HETE inhibition was indomethacin greater than ibuprofen greater than piroxicam.

Tumor-promoting phorbol esters inhibit the binding of colony-stimulating factor (CSF-1) to murine peritoneal exudate macrophages

L-cell colony-stimulating factor (CSF-1) is a sialoglycoprotein of molecular weight 70,000 daltons that specifically stimulates macrophage colony formation by single committed cells from normal mouse bone marrow and by various classes of more differentiated tissue-derived mononuclear phagocyte colony-forming cells (Stanley et al., 1978). CSF-1 interacts with target cells by direct and specific binding to membrane receptors (CSF-1 receptors) that are present only on cells of the mononuclear phagocyte series and their precursors. We studied the effect of tumor-promoting phorbol esters on the binding of 125I-labeled CSF-1 (125I-CSF-1) to murine peritoneal exudate macrophages (PEM). Biologically active TPA (12-O-tetradecanoyl phorbol-13-acetate) inhibits the binding of 125I-CSF-1 to its receptor on PEM. This inhibition exhibits temperature, time, and concentration dependence. At 37 degrees C, maximum inhibition occurred at about 10(-7) M; inhibition was 50% at 5 X 10(-9) M. At 0 degrees C, the inhibitory activity of TPA is diminished. The action of TPA on PEM is transient. Treated cells recover their 125I-CSF-1-binding activity whether TPA is later removed or not. The process of recovering CSF-1-binding activity is completely blocked by the addition of cycloheximide. When several phorbol derivatives were tested for their inhibitory activities, only biologically active phorbol esters were found to possess such activities. Furthermore, the inhibitory activities of various phorbol esters are proportional to their tumor-promoting activities. Inhibition appears to be due to a reduction in the total number of available CSF-1 receptors rather than a decrease in receptor affinity.

Lipopolysaccharide inhibits the binding of colony-stimulating factor (CSF-1) to murine peritoneal exudate macrophages

These studies demonstrate the potent effect of bacterial endotoxin (LPS) on the inhibition of iodinated colony-stimulating factor- (125I-CSF-1) binding by murine peritoneal exudate macrophages (PEM) from C3H/An and C57BL/6 mice. As small an amount as 0.1 ng/ml LPS is sufficient to cause a significant inhibitory effect; this effect is temperature-, time- and concentration-dependent. LPS, however, causes minimal or no inhibition of 125I-CSF-1-binding by PEM from LPS-resistant C3H/HeJ mice. Inhibition of 125I-CSF-1-binding does not appear to be a result of a direct occupancy by LPS of CSF-1 receptors present on the cell membrane and is most likely due to a progressive loss of available CSF-1-binding sites. The effect can be neutralized by the addition of the antibiotic polymyxin B, which binds to the lipid A portion of LPS. The action of LPS on PEM is transient; treated cells recover their 125I-CSF-1-binding activity whether or not LPS is later removed. The restoration of 125I-CSF-1-binding activity can be blocked completely by the addition of cyclohexamide. These findings suggest the rapid, LPS-induced disappearance of CSF-1 receptors from the cell surface may be related to the activation of macrophages by LPS.

Lipopolysaccharide inhibits the binding of colony-stimulating factor (CSF-1) to murine peritoneal exudate macrophages

These studies demonstrate the potent effect of bacterial endotoxin (LPS) on the inhibition of iodinated colony-stimulating factor- (125I-CSF-1) binding by murine peritoneal exudate macrophages (PEM) from C3H/An and C57BL/6 mice. As small an amount as 0.1 ng/ml LPS is sufficient to cause a significant inhibitory effect; this effect is temperature-, time- and concentration-dependent. LPS, however, causes minimal or no inhibition of 125I-CSF-1-binding by PEM from LPS-resistant C3H/HeJ mice. Inhibition of 125I-CSF-1-binding does not appear to be a result of a direct occupancy by LPS of CSF-1 receptors present on the cell membrane and is most likely due to a progressive loss of available CSF-1-binding sites. The effect can be neutralized by the addition of the antibiotic polymyxin B, which binds to the lipid A portion of LPS. The action of LPS on PEM is transient; treated cells recover their 125I-CSF-1-binding activity whether or not LPS is later removed. The restoration of 125I-CSF-1-binding activity can be blocked completely by the addition of cyclohexamide. These findings suggest the rapid, LPS-induced disappearance of CSF-1 receptors from the cell surface may be related to the activation of macrophages by LPS.

Enzyme-linked immunoadsorbent assay for detection of colony-stimulating factor (CSF-1)

An enzyme-linked immunoadsorbent assay (ELISA) has been developed for the quantitative measurement of L-cell colony-stimulating factor (CSF-1). According to this method, purified antigen (CSF-1) was allowed to adsorb to polystyrene or polyvinyl microtiter wells, which were then incubated with specific rat anti-CSF-1 antiserum with or without standard antigen or unknown test samples. The amount of antibody bound to the solid phase was then quantitated by enzyme (horseradish peroxidase)-conjugated rabbit anti-rat immunoglobulin antibody. This assay has a sensitivity comparable to that of the bioassay (approximately 5 U) and can be carried out in a single day.

Relative conversion of arachidonic acid through lipoxygenase and cyclooxygenase pathways by homogenates of diseased periodontal tissues

The present study shows that 14C-arachidonic acid metabolism in gingiva of patients with periodontal disease is mainly via the lipoxygenase pathway. In two pools of gingival tissue homogenates, the lipoxygenase products contained 22.65% and 23.38%, while the prostaglandins (PGs), products of the cyclooxygenase pathway, contained only 4.85% and 3.98% of the total radioactivity incubated. 12-hydroxy-eicosatetraenoic acid (12-HETE), a lipoxygenase product, was detected as a major metabolite of arachidonic acid in gingiva.

Binding, internalization and degradation of colony-stimulating factor by peritoneal exudate macrophages

Iodinated colony-stimulating factor produced by L-cells (125I-CSF-1) binds specifically to murine peritoneal exudate macrophages. At 37 degrees C, the cell-bound 125I-CSF-1 was internalized and degraded very rapidly, with the appearance of radioactive iodotyrosine in the medium. At 0 degree C, the cell-bound 125I-CSF-1 was not internalized and degraded, nor did it dissociate from the membrane. The internalization and degradation at 37 degrees C could be blocked or reduced by the presence of phenylglyoxal, methylamine and NH4Cl. The chemical nature of the CSF-1 binding site is polypeptide as judged by its sensitivity to trypsin treatment. After the binding and degradation of unlabeled CSF-1, the exudate cells were no longer able to rebind freshly added 125I-CSF-1, indicating the removal of CSF-1 binding site. The binding capacity of these cells, however, could be restored by prolonged incubation at 37 degrees C but not at 0 degrees C in culture medium containing fetal calf serum.

Testosterone inhibits prostaglandin formation by human gingival connective tissue: relationship to 14C-arachidonic acid metabolism

The relationship between various concentrations of the male sex steroid, testosterone, and the formation of radioactive prostaglandins (PGs) from 14C-arachidonic acid by human gingival homogenate has been investigated. There were statistically significant (combined) linear and quadratic trends between hormone treatment at concentrations of 10(-9), 10(-7), 10(-5) and 10(-3)M and the amounts of PGF2, PGE2, PGD2 and 15-keto-PGE2 formed. The mean amount of each PG formed at the various concentrations of testosterone was statistically significantly less than the corresponding control level. The results indicate that testosterone, at the dose levels tested, is inhibitory to the cyclooxygenase pathway of arachidonic acid metabolism in gingiva.

Differentiation of various mononuclear phagocyte colony-forming cells by hypotonic lysis

Various classes of murine mononuclear phagocyte colony-forming cells (CFU) present in peritoneal exudate, alveolar spaces, and blood are capable of extensive proliferation and form colonies in vitro. In this study, the sensitivity to hypotonic lysis of the proliferative capacity of various classes of mononuclear phagocyte CFC as well as three cell lines was investigated. The results showed that alveolar CFC (AL-CFC) and a macrophage cell line J774 are most resistant to hypotonic conditions, and the committed stem cells for both granulocytes and macrophages (GM-CFC) and blood monocytes (BL-CFC) are most sensitive to hypotonic conditions. Within 7 min all GM-CFC and BL-CFC are killed but less than 5% of AL-CFC are killed. Peritoneal exudate CFC (PE-CFC) displayed intermediate sensitivity since 50% of them were killed within 7 min in the hypotonic conditions. These data suggest that various classes of mononuclear phagocyte CFC can be distinguished from each other by their ability to resist hypotonic lysis.

Effects of hydrocortisone acetate on pulmonary alveolar macrophage colony-forming cells

We investigated the effect of prolonged monocytopenia induced by daily injections of hydrocortisone acetate on the number of alveolar cells and alveolar macrophage colony-forming cells (AL-CFC) in mice. We did not observe an appreciable reduction in the number of either alveolar macrophages of AL-CFC under this experimental condition, which markedly inhibited the blood monocyte concentration over 10 days. These results suggest the existence of a mechanism by which the number of alveolar macrophages, including AL-CFC, can be maintained without a continuous migration of blood monocytes into alveolar spaces.

The relationship between the concentration of female sex steroids and prostaglandins production by human gingiva in vitro

The relationship between various concentrations of estradiol-17 beta and progesterone, alone and in combination, and the formation of radioactive prostaglandins (PGs) from 14C-arachidonic acid by gingival homogenate has been investigated. There was a statistically significant negative linear trend between each of the hormone treatments at concentrations of 10(-9), 10(-7), 10(-5) and 10(-3)M and the amounts of 6-keto-PGF1a, PGF2a, PGE2, PGD2 and 15-keto-PGE2 formed. Each of estradiol-17 beta and progesterone at 10(-9) and 10(-7)M exerted stimulatory effect, whereas at higher concentrations they had an inhibitory effect on all PGs tested. These observations suggest that the concentration of female sex hormones is an important factor in regulating PG biosynthesis by gingival tissue.