Biphasic regulation of macrophage attachment by activators of cyclic adenosine monophosphate-dependent kinase and protein kinase C

A method is described that enabled us to study the adhesiveness of J-774 murine macrophages. Cell attachment was stimulated by activators of kinase C (i.e., phorbol esters) as well as kinase A (cyclic adenosine monophosphate; cAMP). This novel effect of cAMP was observed when its levels were increased via receptor triggering (prostaglandin E1, beta-adrenergic agonists), activation of Ns (cholera toxin), or inhibition of phosphodiesterase (Ro 20-1724) or when the kinase was directly activated by Br8-cAMP. The simultaneous treatment with kinase A and kinase C activators at the time of attachment resulted in a partially additive response. On the other hand, preincubation of the cells in suspension with one of the activators rendered them refractory to subsequent stimulation at the onset of the adhesion assay, whatever agent was used. Such a refractoriness was also observed in cells preincubated with oleoyl-acetyl-glycerol (OAG). On the other hand, when added at the time of attachment, this near-physiological activator of kinase C evoked a biphasic response: the early stimulation of cell attachment was followed by an accelerated rate of "detachment." In conclusion, kinase C and kinase A play a role in the sequence of events leading to cell adhesion. The cross desensitization observed is distal and takes place at or beyond the kinase step.

Delayed maturation of skin window macrophages in myelodysplastic syndromes

Blood monocyte differentiation to macrophages was examined in nine patients with primary myelodysplastic syndromes using the skin window technique. Emigrated cells were stained cytochemically for acid phosphatase reaction after 1, 2, 4, 7, 9, 12 and 23 h. Compared to age-matched controls, seven patients showed a significant delay in lysosomal enzyme acquisition, which is associated with macrophage differentiation. Our results with this in-vivo assay demonstrate an involvement of the monocyte/macrophage system in primary myelodysplastic syndromes and show that patients often have a disturbance in macrophage differentiation.

Inflammation of rat molar pulp and periodontium causes increased calcitonin gene-related peptide and axonal sprouting

We have studied the response of nerve fibers containing calcitonin gene-related peptide immunoreactivity (CGRP-IR) to inflammation using a rate dental experimental system. Inflammation was induced by drilling tooth cusps to create pulpal exposures; the induced pulpitis and subsequent periapical lesions were studied 1-35 days later using standard CGRP immunohistochemistry and the avidin-biotin peroxidase method. The injury and resulting inflammation caused a disruption of CGRP-IR nerve fiber location and arborization that varied depending on whether the initial injury was limited to the pulp tip or extended throughout the pulp horn. At shorter survival periods (24 hr, 3 days) nerve fibers were either decreased or bundled into the center of the pulp with sprouting along the wound border. At 6 days necrosis and acute inflammation had advanced to varying degrees, and CGRP-IR fibers were extensively sprouted in the surviving pulp; the pulp also stained specifically for CGRP within 1-2 mm of the inflamed tissue at 6 days. At 35 days, we found total pulp necrosis in most teeth and the development of periapical bone loss, granulomatous tissue, and periapical abscesses. There was also an extensive increase in CGRP-IR nerve fibers in the tissues surrounding sites of severe periodontal inflammation and necrosis. In some cases, macrophage-like cells staining specifically for CGRP were near the abscesses. The results show important interactions between peptidergic nerve fibers and inflammatory cells, and are discussed in terms of the role of nerve fibers containing CGRP in neurogenic inflammation, mechanisms for intensification of CGRP immunoreactivity in affected fibers or neighboring cells, and implications for chronic inflammatory conditions, dental pain, and anesthesia.

Immortalization of cloned mouse splenic macrophages with a retrovirus containing the v-raf/mil and v-myc oncogenes

The recombinant retrovirus J2, which contains the v-raf/mil and v-myc oncogenes, was used to immortalize mouse splenic macrophages that had been cloned in soft agar. When added to freshly harvested colonies, J2 failed to yield cell lines but it immortalized up to 30% of the clones if they had been maintained for at least 4 months in medium containing colony-stimulating factor 1 (CSF-1). All of the cell lines grew in agar in a CSF-1-independent manner, and they produced tumors in nude and syngeneic mice. The cell lines were judged to be macrophage based on morphological criteria and because they secreted lysozyme, were phagocytic for antibody-coated particles, and expressed both the Mac-1 antigen and the CSF-1 receptor. The cell lines could be divided into three groups based on their expression of Ia and their ability to present an antigen to a T-cell hybridoma. The majority of the lines did not constitutively express Ia or present antigen, but a lymphokine did induce Ia in all of the lines, with most of them also acquiring antigen-presenting activity. However, a small proportion of lymphokine-treated lines continued to lack antigen-presenting activity despite their ability to express Ia. The third and smallest group of cell lines constitutively expressed both Ia and antigen-presenting activity. These results show that the J2 recombinant retrovirus is a useful means of immortalizing functionally distinct populations of cloned splenic macrophages.

Isolation and characterization of glomerular macrophages in experimental glomerulonephritis

Adherent cells emigrating from glomeruli of rabbits developing anti-glomerular basement membrane antibody induced glomerulonephritis were isolated and characterized as macrophages. Glomeruli were isolated using a sterile graded sieving technique and cultured in plastic tissue culture flasks. After varying culture times, emigrating adherent cells were harvested by 'cold shock' or trypsin-versene. These cells had the morphological and functional characteristics of macrophages. They were largely mononuclear, esterase-positive, phagocytic cells, which exhibited surface Fc receptors. A mean of 4.8 +/- 2.1 X 10(4) macrophages could be isolated from 2 X 10(4) glomeruli after 1 h in tissue culture. Greater numbers of macrophages could be isolated with further time in culture. After 72 h however, intrinsic glomerular cell contamination occurred. The majority of the cells were viable by fluorescein diacetate hydrolysis, and Trypan Blue exclusion. Further functional studies of these cells may provide some new insights into the cellular basis of macrophage-induced glomerular injury in experimental glomerulonephritis.

Mononuclear cell infiltrate and HLA-DR expression in low grade astrocytomas. An immunohistological study of 23 cases

Frozen samples from 23 low grade (grade I and II) astrocytomas were studied by means of a panel of monoclonal antibodies to macrophages, lymphocytes (and their subsets) and HLA-DR antigens. Macrophages were present in low to moderate numbers in 38%-86% of cases, the variance in figures depending on the antibody used. T lymphocytes, the majority of CD8 phenotype, were detected in low numbers in 78% of tumours. B lymphocytes were scanty in 22% (5/22) and totally absent in the remaining cases. HLA-DR antigen was expressed by tumour cells in 35% (6/17) of cases. These findings indicate that in some low grade astrocytomas there is a mononuclear cell infiltrate with macrophages and secondarily CD8+ lymphocytes playing the major role. The significance of these findings remains speculative at present.

Regulation of 1,25-dihydroxyvitamin D3 production by cultured alveolar macrophages from normal human donors and from patients with pulmonary sarcoidosis

Regulation of the production of the biologically active vitamin D3 sterol 1,25-dihydroxyvitamin D3 [1,25-(OH)2D3] by cultured pulmonary alveolar macrophages (PAM) obtained from 6 patients with pulmonary sarcoidosis and from 9 normal subjects was studied. The sarcoid cells, all collected from patients with normal calcium metabolism, synthesized 1,25-(OH)2-[3H]D3 from the substrate 25-hydroxyvitamin [3H]D3 (25OH-[3H]D3), whereas in vitro incubation with recombinant human interferon-gamma (IFN gamma) or lipopolysaccharide (LPS) was required for induction of synthesis of the hormone by normal PAM. Exogenous 1,25-(OH)2D3 (10-100 nmol/L) decreased endogenous hormone production by normal PAM by approximately 45%. The relative inhibitory effect of 1,25-(OH)2D3 was less pronounced in sarcoid PAM, in which 10-100 nmol/L 1,25-(OH)2D3 inhibited 250HD3-1-hydroxylase by approximately 25%. An accompanying induction of the 250HD3-24-hydroxylase, which is typical for renal cells, was found at low levels in only 3 of 10 experiments; in this regard, no differences between sarcoid and normal PAM were apparent. PTH or forskolin did not influence 250HD3 metabolism by PAM. 1,25-(OH)2D3 production by sarcoid PAM was enhanced by lipopolysaccharide and IFN gamma. Likewise, recombinant human interleukin-2 stimulated 1,25-(OH)2D3 production by sarcoid PAM, suggesting a possible role for both IFN gamma and interleukin-2 in the induction of 1,25-(OH)2D3 synthesis by sarcoid PAM in vivo. Recombinant human IFN alpha, IFN beta, and granulocyte-macrophage colony-stimulating factor had little effect. Dexamethasone and chloroquine, which have in vivo antihypercalcemic activity in sarcoidosis, both inhibited 1,25-(OH)2D3 synthesis by sarcoid PAM; chloroquine simultaneously stimulated the 24-hydroxylase. Our studies suggest that the 250HD3-metabolizing system in PAM is in some respects different from renal metabolism of 250HD3.

Cryptogenic abscess of the liver. Evidence of underlying reticuloendothelial cell dysfunction

Evidence of underlying liver disease and reticuloendothelial system dysfunction was sought in five adults with histories of idiopathic or "cryptogenic" liver abscess. Although no evidence of underlying liver disease was obtained (median follow-up, 3.4 years; range, 2.1 to 4.8 years), four of five individuals demonstrated a marked impairment in their ability to clear antibody-tagged erythrocytes from the systemic circulation. The results of this study suggest that patients who develop cryptogenic abscesses of the liver have an underlying reticuloendothelial cell defect that may predispose them to liver abscess formation.

Isolation and characterization of macrophages from scrapie-infected mouse brain

We have isolated and characterized a population of brain macrophages from normal and scrapie-infected mice. The cells are phagocytic, possess Fc-IgG receptors, Mac-1 surface antigen and proliferate in the presence of macrophage colony stimulating factor. They resemble microglia in that they have a plasmalemmal distribution of the enzyme nucleoside diphosphatase, a property tht is characteristic of microglia in situ. In two of the three combinations of scrapie agent and mouse strain examined, the number of brain macrophages was several fold higher than in normal control mice. The increase was not observed in mice infected intraperitoneally or in control mice inoculated with normal brain homogenate. The increase is detectable as early as 3-5 weeks postinoculation. The agent/host combination that failed to show an increase in brain macrophages is one that develops large numbers of amyloid plaques. These observations suggest that these cells are closely associated with the scrapie pathogenic process in the CNS. The failure of these cells to increase in the plaque forming model of scrapie disease also suggests that they play a role in the control of CNS amyloidogenesis.

Total parenteral nutrition in mice bearing a metastatic carcinoma: tumor growth, metastasis and immunologic parameters

The role of dietary manipulation of tumor growth, metastasis and immunologic parameters was studied in mice bearing Lewis lung carcinoma. Fourteen days following subcutaneous tumor implant, groups with tumor and their non-tumor bearing counterparts were assigned to one of the following feeding protocols: total parenteral nutrition (TPN), per oral (PO) intake of the parenteral diet, an oral casein diet (CAS), or electrolyte infusion plus the casein diet (ELECT). Intakes of energy and nitrogen were similar among all groups. Mice were killed 12 days later and peritoneal macrophages were tested for phagocytic activity. Tumor growth and metastasis were decreased from both infusion regimens with minimal loss of body weight as compared with casein fed mice. PO mice also showed lower tumor weight but metastasis was as great as in the casein group. Non-tumor-bearing infused mice showed depressed thymic weight, but thymic weight was not further reduced in tumor-bearing infused mice. PO feeding afforded no such protection in the presence of the carcinoma. Splenomegaly was observed in tumor-bearing mice on all regimens, but mice maintained on the parenteral diet demonstrated the largest proportion of macrophages containing nuclear debris. Analysis of free macrophages indicated no effect of diet regimen on non-immune phagocytic activity in both tumor-free and tumor-bearing mice. Possible alteration of splenic macrophage intracellular digestive capacity or phagocytic activity was suggested as a result of TPN.

Hematogenous origin of brain macrophages: a case report

Del Río-Hortega believed that phagocytic cells in the CNS arise from microglia; however, recent autoradiographic studies have suggested a hematogenous origin for brain macrophages. To clarify this issue, we studied a young man with acute lymphoblastic leukemia and a peripheral white blood cell count of 22/mm3 who had an embolic brain infarct 2 weeks before he died. Macrophages were scarce within the lesion, suggesting that the principal phagocytic cell is hematogenous.

Stimulation of neovascularization by human rheumatoid synovial tissue macrophages

Synovial tissue from patients with rheumatoid arthritis was enzymatically dissociated, and single cell suspensions were fractionated into subpopulations by centrifugation on continuous Percoll gradients. Five fractions (F1-F5) with densities of 0.991-0.998 gm/ml, 0.998-1.042 gm/ml, 1.042-1.062 gm/ml, 1.062-1.082 gm/ml, and 1.082-1.180 gm/ml, respectively, were prepared. F3 consistently contained the highest number of macrophages, while F2 and F4 contained substantially fewer macrophages. Macrophages present in F2, F3, and F4 were enriched by differential adherence to fibronectin-coated collagen gels. These macrophage-enriched cell preparations were found to be Fc and C3 positive, esterase positive, and peroxidase negative, to stain positively with anti-HLA-DR, anti-Leu-M3, OKM1, and OKM5 monoclonal antibodies, and to show characteristic features of macrophages by electron microscopy. Macrophages from F3 consistently induced neovascularization in rat corneas, while equal numbers of macrophages from F2 and F4 did not. Fibroblastic synovial cells and cells that did not adhere to fibronectin-coated collagen gels did not induce neovascularization. Within the rheumatoid synovium, there appears to be a major subpopulation of macrophages capable of inducing neovascularization, a process vital to the development of the rheumatoid synovial pannus.

Ectopic hematopoiesis in peritoneal tumor nodules induced by the myeloproliferative sarcoma virus in DBA/2 mice

Tumor nodules composed of fibroblasts, large undifferentiated cells, granulocytes, and small lymphocytes develop in the spleens of adult DBA/2 mice infected with the myeloproliferative sarcoma virus (MPSV). They spread thereafter in the organism, and at the terminal stage of the disease they are especially numerous on the peritoneal membrane. The present study, performed on those tumor nodules to avoid contamination by exogenous hematopoietic cells, demonstrated that they were sites of granulopoiesis, which may have occurred via the local differentiation of granulomacrophage precursor cells (GM-CFC) and perhaps also from pluripotent hematopoietic stem cells, since these two populations were present in the tumor nodules (25 +/- 11 and 13 +/- 10, respectively, per 5-10(5) cells). Almost all (88%) those GM-CFC were able to clone in vitro without added colony-stimulating factor. A comparative study with the Moloney murine sarcoma virus-induced tumor indicated that the local production of hematopoiesis-stimulating factors was not sufficient to allow such ectopic granulopoiesis. These results imply the presence of a specific hematopoietic microenvironment in the MPSV-induced tumor nodules.

Pulmonary macrophage mobilization in cigarette smoke-exposed mice after halothane anesthesia

The effects of halothane anesthesia on pulmonary tissue and lung macrophage population were evaluated in normal and in C57BL/6 mice exposed to cigarette smoke twice daily for one year. Morphologic assessment of pulmonary tissue revealed no lung abnormalities that could be attributed solely to halothane anesthesia. However, in animals that were exposed to smoke and subsequently halothane anesthesia, airways cilia were shorter in stature and fewer in number. Disorientation of ciliary basal bodies was also observed. Airway macrophages in smoke-exposed animals subjected to halothane anesthesia were, for the most part, larger in size and contained more lysosomes and inclusions than phagocytes in airways of all other animals. Smoke inhalation alone caused a significant increase in number of lung parenchymal macrophages when compared to the number of these cells in sham-treated and control animals. However, the total macrophage population was significantly greater in lungs of smoke-exposed mice 48 hr after anesthesia than in lungs of smoke-exposed mice not subjected to halothane anesthesia and to those of sham-treated and control animals that were or were not exposed to the anesthetic. Airway macrophage numbers were significantly elevated in smoke-exposed mice 48 hr after halothane when compared to those of all other groups. Conversely, the number of parenchymal macrophages decreased in lungs of these mice. It was proposed that in smoke-exposed mice subjected to halothane anesthesia, ciliary function is impaired and phagocytes are mobilized from alveoli into the airways.

Studies of macrophage function in murine systemic lupus erythematosus. 4. Failure to reverse the defect in Fc-mediated phagocytosis and binding by in vitro stimulants or prostaglandins

Previous studies have shown that resident peritoneal macrophages from mice with systemic lupus erythematosus (SLE) show defective Fc-mediated phagocytosis and binding of opsonized sheep erythrocytes (EA) in vitro. Possible causes of this defect in (NZB X NZW)F1 (B/W) mice were investigated. These included a maturational block in peritoneal macrophage differentiation, the production by peritoneal cells of a factor which inhibits Fc receptor expression and phagocytosis, and an abnormal response by macrophages of autoimmune mice to prostaglandins. Resident peritoneal macrophages of B/W mice did not show a maturational block since incubation with either (a) differentiating agents such as 4 beta-phorbol 12 beta-myristate 13 alpha acetate or retinoic acid, or (b) lymphokine (LK), prepared by Con A stimulation of mouse spleen cells, failed to enhance Fc-mediated phagocytosis and binding by B/W cells relative to controls. However, LK from B/W and B6AF1 cells stimulated Fc-mediated phagocytosis and binding by bone-marrow (BM)-derived macrophages of CBA/H mice; B/W LK also stimulated BM cells from B/W mice. Peritoneal cell supernatants did not inhibit phagocytosis of Fc receptor expression by BM-derived macrophages in vitro. Prostaglandin E treatment of peritoneal or BM-derived macrophages in vitro failed to restore decreased phagocytosis and binding of EA induced by culture in indomethacin and failed to stimulate phagocytosis by untreated cultures. The reason for the observed defect remains obscure.

Early cellular events in pulmonary fibrosis

In this review we have surveyed recent investigations of early cellular events in pulmonary fibrosis both in animal models and in human diseases. Analysis of the interactions of the numerous cell types in the lung following injury is an almost overwhelmingly complex enterprise. In the animal models experimental design has a profound effect on results, making it difficult to compare studies when species, fibrogenic agent, dose, route of exposure, schedule of administration, time course, and analytical methods may not be equivalent. In human diseases we are rarely able to obtain data at precisely the same time point in the course of the disease even among patients in the same study, and possible confounding variables present are legion. Transcending these difficulties for the moment, can we draw any conclusions from our current knowledge of early cellular interactions in pulmonary fibrosis? What is striking is not that there are so many agents that can potentially induce pulmonary fibrosis, but that the lung has such capabilities for recovery. Although the major effector cells may all initially participate in damaging the lung and initiating fibrosis, there is evidence that they may also have the capacity to participate in subsequent repair. Macrophages may initially recruit fibroblasts and stimulate them to proliferate, only to suppress them subsequently. Macrophage production of prostaglandins can lead to suppression of macrophage, neutrophil and lymphocyte responses, thus attenuating tissue injury and the development of fibrosis. Neutrophils may initially release toxic metabolites and enzymes that damage parenchyma. However, there is evidence that they may later play a role in attenuating fibrosis, perhaps through collagenase secretion, or through as yet unknown mechanisms. Lymphocytes may initially participate in a number of damaging ways by secreting chemoattractants for other cells and participating in destructive autoimmune processes. However, there is evidence that subpopulations of T cells may dramatically shift during the course of fibrosis, leading to attenuation of the process. It may thus be useful to consider irreversible pulmonary fibrosis as the end result of a process in which the balance of normal injury/repair mechanisms is disrupted. There is clearly no single "fibrogenic event." Rather, there seem to be a number of places where disruption of balance/repair processes may begin. In diseases of unknown etiology such as sarcoidosis or IPF, loss of control may occur at the genetic level, leading to the destructive alveolitis that is the apparent precursor of fibrosis.(ABSTRACT TRUNCATED AT 400 WORDS)

Studies of macrophage function in murine systemic lupus erythematosus. 3. The nature, anatomical location, and reversibility of the phagocytic defect

The defect in phagocytosis and binding of antibody-coated sheep erythrocytes (EA) by peritoneal macrophages of (NZB X NZW)F1 or B/W mice is not intrinsic, but is related to the development of the autoimmune disease process. The defect appears to be confined to peritoneal macrophages, since bone marrow (BM)-derived macrophages have normal to elevated activities in vitro. The peritoneal macrophage defect is not due to blockade of Fc receptors in vivo, as shown by long-term culture or recovery of phagocytic and binding activities after removal of Fc receptors by pronase, but represents a reduced number of receptors with slightly delayed turnover. The defect can be reversed by elicitation of activated macrophages with Corynebacterium parvum, thioglycollate, or proteose peptone in vivo. Normal Fc-mediated phagocytosis and binding by BM-derived macrophages cultured from untreated autoimmune mice is enhanced by pretreatment of mice with C. parvum, thioglycollate, or proteose peptone. The cause of the defect in Fc-mediated phagocytosis by resident peritoneal macrophages of autoimmune mice was not ascertained; it may be due to abnormal macrophage kinetics or to the local effects of lymphokines released as a result of other autoimmune changes.

Leukokinesis in bovine ostertagiasis: stimulation of leukocyte migration by Ostertagia

A blind-well chemotaxis chamber method was used to indicate migration stimulation of bovine neutrophil and eosinophil polymorphonuclear leukocytes and macrophages as related to ostertagiasis. Live exsheathed Ostertagia ostertagi 3rd-stage larvae (L3) and soluble L3 antigen (SLA), prepared by freeze thawing and sonic disruption of L3, enhanced cellular migration for eosinophils, but not for neutrophils and macrophages. Products of lymphocytes cultured with SLA for 3 to 6 hours were also examined, using lymphocytes from peripheral blood of helminth-free cattle and cattle infected with O ostertagi or Trichostrongylus axei. Lymphokines that enhanced cellular migration of neutrophils, eosinophils, and macrophages were present in culture supernatants of SLA-stimulated lymphocytes from O ostertagi-infected cattle, but not from cattle infected with T axei or helminth-free cattle. Seemingly, L3 and SLA were stimulants of eosinophil migration. Further, neutrophil, eosinophil, and macrophage migration was modulated by lymphokines produced by SLA-stimulated lymphocytes from cattle with ostertagiasis.

[Micro and macrophage function test in patients with lichen ruber planus]

Various micro- and macrophage functions were studied in vitro in 21 patients suffering from lichen ruber planus and in 100 healthy individuals. A slight impairment of chemotactic activity of microphages (12/21) and a reduced capacity of intracellular inactivation of microorganisms in both systems (14/21; 3/12) were found.

Alveolar macrophage mediated pulmonary clearance suppressed by drug-induced phospholipidosis

Drug-induced phospholipidosis in rats treated with chlorphentermine (CP) for 4-7 days suppressed totally alveolar pulmonary clearance in the first days after a TiO2 aerosol exposure. Reversing phospholipidosis by treatment interruption led to a recovery of particle clearance. Morphological observations indicated that "foam cells" contained less TiO2 particles than alveolar macrophages (AM) of control rats. Clearance of ZnO particles which seems not to be mediated by AM was not affected by CP treatment. A grand average retention curve based on data from control groups of past experiments suggests that alveolar clearance of TiO2 particles has a phase 1 (T 1/2 = 7 days) lasting about 2 weeks and a phase 2 (T 1/2 = 69 days). The results with drug-induced phospholipidosis suggest that phase 1 is practically totally AM-mediated. Drug-induced phospholipidosis is a promising method for the study of AM involvement in defensive functions.

[Growth stimulation in a Ewing sarcoma after "macrophage blockade" in athymic (nude) mice]

Inoculation of cell suspensions of a Ewing sarcoma (1.5 to 2.0 x 10(8) viable cells/mouse) into thymus less nude mice bred under conventional conditions gave a 90% take rate after subcutaneous injection and 35% after intraperitoneal. Intraperitoneal take rate is raised to 90% by intraperitoneal pretreatment with India ink. The same pretreatment shortens the tumor doubling time after subcutaneous inoculation. Both events are probably caused by inhibition of macrophages and/or natural killer cells.

Immunological regulation of experimental cutaneous leishmaniasis. 2. Studies with Biozzi high and low responder lines of mice

Susceptibility to Leishmania tropica was studied in Biozzi 'high' (Ab/H) and 'low' (Ab/L) responder mice of Selections I and III which, although originally selected with heterologous erythrocytes and Salmonella flagellar antigens respectively, both show non-specific separation of antibody responses. Ab/H Sel I produce only small lesions, even with the largest infecting dose, which heal after 2 months with minimal antibody responses. Specific delayed-type hypersensitivity (DTH) levels found in both are normal and equivalent. (Ab/H x Ab/L)F1 mice behave intermediately. A smaller inter-line difference is only detectable in Sel III with lower infecting doses. Both Ab/L and Ab/H mice given high doses develop chronic non-healing disease. These results imply that spontaneous resolution of cutaneous L. tropica lesions during the immune phase is independent of humoral antibody. While the great resistance and slower development of lesions found in Ab/L Sel I are entirely consistent with the macrophage 'hyperactivity' characteristic of the line, attempts to demonstrate this in vitro with comparisons of infected peritoneal exudate have been inconclusive so far.

Effect of hyperthermia on rabbit macrophages

The effect of water-bath hyperthermia on rabbit peritoneal macrophages was studied in vitro. The cells were exposed to hyperthermia for 30 min to 4 hours and membrane transport of ions as measured by total and ouabain-inhibited 86Rb influx as well as membrane permeability for 86Rb and 51Cr-labelled intracellular proteins were investigated. Heat-treated macrophages were tested for their ability to phagocyte staphylococci and for reduction of nitroblue-tetrazolium. Moreover the effect of microwave whole-body hyperthermia on rabbit phogocytic cells was studied in vivo. Ion transport to macrophages was stimulated by both intensive (43 degrees C) and moderate (40 degrees C) hyperthermia. On the other hand exposition of the cells to 43 degrees C led to pronounced release of 86Rb and 51Cr from prelabelled cells. NBT reduction was generally decreased in macrophages exposed to 43 degrees C and increased in macrophages kept at 40 degrees C. Clearance of 32P-labelled staphylococci from peripheral blood of microwave-irradiated rabbits diminished when animals were exposed to microwave hyperthermia for f or 7 days (2 hours daily).

Lymphocyte-macrophage-fibroblast co-operation in the inflammatory degradation of cartilage and connective tissue

In tissue culture models of cartilage and connective tissue degradation, rabbit macrophages and fibroblasts are both independently capable to degrade cartilage proteoglycan due to the secretion of a metal-dependent neutral proteinase. However, only the fibroblasts significantly degrade the collagen due to a sufficient production of collagenase. Macrophages produce factor(s) that stimulate the secretion of collagenase and the degradation of collagen by fibroblasts. Soluble products released by stimulated lymphocytes increase that production and also markedly enhance the secretion of proteoglycan-degrading proteinase and of collagenase by the macrophages. These data support the view that macrophages and fibroblasts are among the main effector cells of cartilage degradation in rheumatoid arthritis and that they are regulated in this function by secretory products of nearby lymphocytes.

Tobacco smoke and the pulmonary alveolar macrophage

Our results indicate that tobacco smoke exposure to varying duration causes morphological, biochemical and functional alterations in pulmonary alveolar macrophages. The results of these changes is a population of alveolar macrophages made up of larger cells, with a reduced nucleus-cytoplasmic ratio, which are heavily loaded with heterolysosomes containing lipid. Though their fractional complement of mitochondria remains the same, an increase in the inner mitochondrial membrane surface area may be related to an enhanced oxidative metabolism. The cell is biochemically activated particularly following chronic exposure and is functionally impaired with respect to phagocytosis.

Morphogenesis and pathogenesis of chronic lung diseases. XVI. The influence of drugs on the stereotyped development and cellular kinetics of experimental lung granulomas

The stereotyped development and the cellular kinetics of lung granulomas experimentally-induced in rabbits by an intravenous injection of the complete Freund adjuvant with addition of human gammaglobulin, were studied under the influence of hydrocortisone acetate, rifampicin, heparin and phenobarbital. As in a previous study using actinomycin and puromycin, the analysed drugs delayed up to inhibition (hydrocortisone) the development of lung granulomas which remained small, unfused, without epithelioidosis; the primary and secondary immune responses were more or less influenced up to their suppression. The delivery of macrophages was reduced by hydrocortisone, but enhanced by heparin and phenobarbital. The latter induced a persistent intragranulomatous granulocytosis, expressing the repair of decreased activities of dehydrogenases and especially of NADP-NADPH-oxidases. The action of these drugs was phasic, their intervention being active only during the cellular phase of granulomas; fibrillogenesis was influenced only indirectly. Extrapolation to humans of these results suggests the use of these drugs during the cellular phase of chronic pneumonitic lesions and suppression of the immune component of the inflammatory processes.

Reversal of impaired splenic function in patients with nephritis or vasculitis (or both) by plasma exchange

By studying the clearance of autologous labeled antibody-coated or heat-damaged erythrocytes, we showed that reversible blockade of the splenic component of reticuloendothelial function existed in 14 of 15 patients referred for treatment of nephritis or vasculitis. In 10 patients treated by plasma exchange--alone in three and combined with steroids and cytotoxic drugs in six--reversal of splenic blockade followed in nine, and in the three patients treated solely by plasma exchange this reversal was demonstrated to occur within 48 hours of the procedure. Only gradual reversal of splenic blockade was found in three of five patients treated by steroids with or without cytotoxic drugs; no change in splenic function was observed in two. When circulating immune complexes were detected by a C1q-binding assay, there was, in serial studies, an approximate inverse correlation between splenic function and the level of C1q-binding material, though hyposplenism was also a feature of patients in whom the C1q-binding assay was negative.

[The influence of cyclophosphane and phenthyrine and their combination with zymosan and serotonin on the functional features distingusihing peritoneal macrophages in mice]

Radiometric analysis into phagocytic activity of macrophages in intact and tumourous mice following introduction to them of phenthyrine and cyclophosphane showed the former to suppress to a greater extent the absorption function and the latter--that of digestion. A combined application of phenthyrine and cyclophosphane together with serotonin helps re-establish the microphages function in tumourous animals and to heighten the antineplastic activity of these compounds. Zymosan and its combination with phenthyrine and cyclophosphane do not produce any positive effect on the peritoneal cells.

Bone volume and mineral density of iliac crest spongiosa in uremia

Bone mass and bone mineral content were measured in non-dialyzed and dialyzed uremic patients. Bone mass, measured by micromorphometry and a gas displacement method, was higher in uremic than in age and sex matched control subjects (micromorphometry-U:25.8 +/- 8.24%; Co:15.6 +/- 4.38; gas displacement-U:211 +/- 66 mm3/cm3; Co:191 +/- 45). In hemodialyzed patients, bone mass was lower the longer the patients had been on dialysis (r = 0.38; P 0.05). Bone mineral content (specific weight) was diminished in uremia (1.82 +/- 0.095 g/ml; controls 1.854 +/- 0.0173). In hemodialyzed patients, specific weight was higher, as was Ca content of bone assessed by neutron activation analysis. It is concluded, that negative Ca balance was the major cause of bone loss and that bone loss is thus preventable.

Activation of alveolar macrophages after lower respiratory tract infection

Alveolar macrophage function has been studied in relation to bacterial infection of the lower respiratory tract. First, LRT macrophages were examined after exposure of rabbits to Listeria monocytogenes aerosols. Macrophages obtained from the LRT of animals 10 to 48 days after infection were activated, as evidenced by greater adherence to culture dishes and increased ability to ingest and kill both the original infecting organism and unrelated organisms, when compared to normal alveolar macrophages. Next, the in vitro effects on normal alveolar macrophages of incubation supernatants of control and antigen-stimulated lymphocytes (LRT and lymph node) from animals infected with L. monocytogenes or Streptococcus pneumoniae were evaluated. As manifested by increased adherence and phagocytosis, and an enhanced nonspecific bactericidal activity, alveolar macrophages were activated by the antigen-stimulated supernatants. These stimulated lymphocyte supernatants contain lymphokines (MIF), but the exact nature of the alveolar macrophage activating factor(s) remains to be determined. These observations, together with recent evidence that alveolar macrophages respond to lymphokines (MIF), suggest that the effector mechanism for cell-mediated immunity in the LRT is intact.

The proliferation of astrocytes around a needle wound in the rat brain

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