In vitro cell response of Treponema pallidum-infected rabbits. III. Impairment in production of lymphocyte mitogenic factor.

Production of mitogenic factor was examined in rabbits infected intratesticularly with T. pallidum and in control animals injected with saline or saline extract of normal rabbits' testes. Lymph nodes and spleen from animals killed 2, 6 and 12 weeks after injection were used as the source of lymphocytes, cultured in serum-free medium in the presence of Reiter antigen. The active supernatants of lymph node cells (LNAS) and spleen cells (SPAS) were examined for the presence of mitogenic factor using normal rabbit peripheral lymphocytes. The LNAS of control animals showed a mitogenic index (MI) between 4 and 6 and the infected animals less than 2. The SPAS of infected and control rabbits showed an MI of less than 2. The lower mitogenicity in LNAS of infected and that of SPAS of infected and control animals seems to be due to the presence of inhibitors of DNA synthesis.     

BCL1, a murine model of prolymphocytic leukemia. II. Morphology and ultrastructure.

The transplantable murine B-cell leukemia, BCL1, was examined by light and electron microscopy. The results show that the BCL1 cell closely resembles the prolymphocyte of human prolymphocytic leukemia (PLL). The spleen of animals transplanted with BCL1 is diffusely infiltrated by BCL1-prolymphocytes. Splenectomized animals given transplants of BCL1 develop a lymphomalike disease with less leukemia and bone marrow involvement than the nonsplenectomized transplant recipients. Ultrastructural features of the BCL1 cell are identical in the splenectomized and nonsplenectomized animals.     

Immune mechanisms to Ascaris suum in inbred guinea-pigs. I. Passive transfer of immunity by cells or serum.

Syngeneic Strain 2 guinea-pigs which received seven s.c. injections of infective eggs of Ascaris suum were shown to harbour less larvae in their lungs than control animals after mesenteric vein challenge with 10,000 infective larvae of A. suum. Serum and cell preparations harvested from these animals were able to transfer protective immunity to normal recipients to varying degrees. Significant protection with serum preparations was obtained with immune IgG2, IgE + IgG1 and whole immune serum. Best protection with cell preparations was obtained with a pool of cells from the mesenteric, hepatic (retropancreatic), and mediastinal nodes of immune animals. Cells from the hepatic nodes of immune animals were more effective than cells from the mediastinal and mesenteric nodes. Immune spleen cells enhanced, rather than reduced, the degree of the infection. Cells or serum preparations from normal animals were not capable of transferring portective immunity to normal recipients.     

Age-dependent gene induction in quail oviduct. VII. Alteration of DNA polymerase activities in response to progesterone treatment.

The changes of DNA synthesis as well as the alterations of DNA polymerase alpha and beta have been determined in oviducts from immature (35 days old), mature (about 300 days old) and senescent (about 3 years old) quails in response to diethylstilbestrol (DES). The DNA synthesis in oviducts from immature quails is strongly stimulated by DES; after 12 days, values equivalent to those determined in mature and senescent animals are reached. The DNA synthesis in immature oviducts can be reversibly blocked by progesterone administration; no influence is observed in the case of DNA synthesis in mature as well as senescent animals. During DNA synthesis in immature oviducts, stimulated with DES, DNA polymerase alpha is strongly induced. Co-administration of progesterone blocks this enzyme induction in a reversible and strong way. The activity of DNA polymerase alpha is identical in mature and in immature animals (after DES treatment for 15 days); the activity of the same enzyme in senescent animals is about 40% lower than the values found in the younger quails. The activity of DNA polymerase beta is not altered if the animals are treated with DES or with DES and progersterone; however, the basic level of the enzyme in senescent animals in 50% lower than in immature or in mature animals.     

Host immune status in uraemia. I. Cell-mediated immune mechanisms.

An experimental model of stable uraemia has been used to determine the effect of uraemia on cell-mediated immune mechanisms in the rat. Controlled resection of renal tissue allowed the establishment of a 'moderate' (blood urea 100-200 mg/100 ml) and 'severe' grade of uraemia (BU > 200 mg/100 ml). The immune responsiveness of isolated lymphocyte suspensions from uraemic animals was similar to that of sham-operated animals but lymphocyte function in both groups was suppressed compared with control non-manipulated animals. This was particularly evident in the graft vs host reaction. The host vs graft which assumes the cell-mediated immune status in the live animals, was also depressed in the uraemic animals but in contrast to the previous results sham-operated animals exhibited normal responses. The results underscore the importance of surgically induced anergy as a factor complicating the assessment of immune function in uraemia and may explain some of the inconsistencies observed in the evaluation of cell-mediated immunity by in vitro analysis of lymphocyte suspensions and tests of immune function in the intact host.     

Host defence mechanisms in the bladder. I. Role of mechanical factors.

This study evaluated the contribution of host defence mechanisms to bacterial clearance from the urinary bladder using an animal model in which rats were infected with Escherichia coli. Factors studied included the effect of hydration status, induced ultrastructural changes to the surface of the bladder mucosa, and the relevance of bacterial replication. Clearance was divided into two phases, primary (0-4 h), and secondary (4-24 h). Ninety-nine per cent of Escherichia coli 075 was cleared during the primary phase from normal, dehydrated and polyuric animals and 93% from anuric animals. Clearance was shown to be dependent on the presence of viable tissue. Bacterial numbers continued to decrease during the secondary phase in normal and dehydrated animals but increased in polyuric and anuric groups. No such rise occurred when rats were inoculated with Escherichia coli E/2/64, a non-replicating mutant. Evidence of ultrastructural changes to the bladder associated with impaired antibacterial properties was found in polyuric and anuric animals. Clearance of particulate matter (killed Candida albicans) however was unaffected by mucus disruption. The study has shown that the clearance of microorganisms from the bladder was unrelated to the voided volume, but is closely associated with the antibacterial activity of the mucosal surface.     

Influence of some antidepressant drugs on the circulatory system. I. Imipramine.

Imipramine exerts various, dose-related, effects on arterial blood pressure. A distinct hypotensive effect occurs at dosses of at least 0-5 mg/kg body weight. At lower dosage, the action of the drug is biphasic. In experiments in situ with animals, imipramine diminished amplitude of the heart's contractions. Controlled respiration during experiments with imipramine reduced its toxicity. In decapitated animals the action of imipramine was the same as in animals with intact central nervous system. At all dosage levels its effect on blood pressure was biphasic. Blockade of the sympathetic, parasympathetic system and vegetative ganglia had no significant effect on the circulatory response to imipramine. Low doses of imipramine potentiated the hypertensive effect of noradrenaline, and high doses weakened it.     

Pulmonary hemodynamics modify the rat pulmonary artery response to injury. A neointimal model of pulmonary hypertension.

Hemodynamic factors have profound influences on blood vessels. To test the hypothesis that hemodynamic conditions modify the pattern of remodeling in response to injury, monocrotaline (MCT) injury in Sprague-Dawley rats was followed 1 week later by left pneumonectomy to increase blood flow to the right lung. Right pulmonary artery remodeling in these MCT plus pneumonectomy animals was compared with animals receiving MCT or pneumonectomy alone. Neointimal changes developed in more than 90% of all right lung intra-acinar vessels 5 weeks after MCT injury (4 weeks after pneumonectomy). Neointimal lesions did not develop in untreated animals or in animals receiving MCT or pneumonectomy only. Animals with a neointimal pattern of remodeling developed severe right ventricular hypertrophy (RVH) whereas animals with a medial hypertrophy pattern of remodeling (MCT only) developed moderate RVH compared with control animals. Neointimal lesions and RVH were similar whether injury preceded pneumonectomy or vice versa. To exclude the possibility that neointimal lesions resulted from injury plus post-pneumonectomy compensatory lung growth, rather than injury plus increased flow, a left subclavian-pulmonary artery anastomosis was substituted for pneumonectomy. Neointimal lesions and severe RVH developed in these animals but were not seen in animals receiving either MCT or anastomosis only. These studies demonstrate an important role for hemodynamics in determining the pattern of pulmonary vascular remodeling after injury.     

Kinetics of acute inflammation induced by Escherichia coli in rabbits. II. The effect of hyperimmunization, complement depletion, and depletion of leukocytes.

The inflammatory response to Escherichia coli was quantitated in the skin of normal rabbits and the kinetics established as described previously. Hyperemia, measured with radiolabeled microspheres; vascular permeability, estimated with 125 I-albumin; and leukocyte infiltration, quantitated with 51Cr-labeled autologous leukocytes, reached maximal values 3 hours after the injection of bacteria and subsided almost completely by 6 hours. Hemorrhage, measured with homologous 59Fe-erythrocytes, continued to increase between 1 and 6 hours after injection and then reached plateau levels. The lesions were studied up to 8 hours, since in the previous study no changes were observed beyond that time. In the study described in this paper, the host mediation systems were manipulated in various groups of rabbits in order to elucidate the mechanisms underlying the development of the inflammatory reaction. One group of animals was hyperimmunized with the E coli organisms, another was partially depleted of hemolytic complement with cobra venom factor, and yet another was rendered leukopenic with nitrogen mustard. In hyperimmunized animals hyperemia in the dermal lesions induced by the microorganisms was significantly more intense than in normal rabbits. Vascular permeability increase occurred earlier in hyperimmunized rabbits and at 1 hour was significantly greater than in normals. Decomplemented rabbits had significantly less vascular permeability than normal animals, whereas in leukopenic rabbits no increase in vascular permeability could be elicited. Leukocyte accumulation was increased over the normal animals in the lesions of hyperimmunized rabbits. Hemorrhage was significantly decreased in leukopenic rabbits. Histologic examination of the lesions revealed that whereas in normal animals the infiltrating neutrophils ingested most of the bacteria and formed definite abscesses by 6-8 hours, these abscesses were absent in leukopenic animals, and free-lying bacteria were demonstrable in lesions. Histologically more neutrophils were present in the hyperimmunized than in the normal rabbits, but this difference was striking when normal animals were compared with leukopenic animals, in some of which only very occasional small accumulations of neutrophils were present.     

Effect of glucocorticosteroids on phagosome-lysosome interaction.

The effects of hydrocortisone on fusion of thorotrast-labeled lysosomes with phagosomes containing killed toxoplasmas was studied. Mouse peritoneal macrophages from glucocorticosteroid-treated animals fromed phagolysosomes just as effectively as macrophages from untreated animals (72% thorotrast-positive vacuoles in hydrocortisone-treated animals; 78% in controls). The electron microscopic appearence of macrophages from treated or untreated animals was similar. This observation complements studies which show no change in intracellular microbicidal activity in macrophages treated with glucocorticosteriods.     

Pathology of Clostridium welchii type D enterotoxaemia. 3. Basis of the hyperglycaemic response

It has been demonstrated that the hyperglycaemia, which is a prominent feature of Clostridium welchii type D epsilon toxin intoxication, results from rapid mobilization of hepatic glycogen.Liver glycogen stores are rapidly depleted in intoxicated animals and no elevation of blood glucose level occurs in animals in which hepatic glycogen has been depleted prior to intoxication.No detectable interference with tissue respiration could be demonstrated in tissues from intoxicated animals, suggesting that the hyperglycaemia is not the result of interference with glycolysis.     

Behaviorally conditioned immunosuppression.

An illness-induced taste aversion was conditioned in rats by pairing saccharin with cyclophosphamide, an immunosuppressive agent. Three days after conditioning, all animals were injected with sheep erythrocytes. Hemagglutinating antibody titers measured 6 days after antigen administration were high in placebo-treated rats. High titers were also observed in nonconditioned animals and in conditioned animals that were nor subsequently exposed to saccharin. No agglutinating antibody was detected in conditioned animals treated with cyclophosphamide at the time of antigen administration. Conditioned animals exposed to saccharin at the time of or following the injection of antigen were significantly immunosuppressed. An illness-induced taste aversion was also conditioned using LiCl, a nonimmunosuppressive agent. In this instance, however, there was no attenuation of hemagglutinating antibody titers in response to injection with antigen.     

Seroepidemiological studies of Borrelia burgdorferi infection in sheep in Norway.

An enzyme-linked immunosorbent assay for antibodies to Borrelia burgdorferi in sheep was established. The assay was used in a seroepidemiological survey in which serum samples from 327 Norwegian rams were screened for antibodies to B. burgdorferi. These rams were randomly chosen, clinically healthy animals from all parts of Norway. They came both from areas where Ixodes ricinus is common and from areas where the tick has not been found. The age of the animals varied from 0.5 to 7.5 years. Sera from 10% of the animals tested were seropositive by the enzyme-linked immunosorbent assay, with the percentage of positive animals varying from 0 to 20% between counties. The distribution of seropositive animals was generally in good agreement with the known distribution of I. ricinus, with the highest proportion of seropositive animals being in southern coastal areas of Norway. There were some exceptions, however, because seropositive animals were also found in areas where the tick has not been recorded. The majority of animals appeared to become infected during the first 2 years of life, with 12% of animals that were 1.5 years old being seropositive. The animals were all healthy at the time of serum sampling, and the clinical significance of B. burgdorferi in sheep is still uncertain.     

Lung lymphatics increase after hyperoxic injury. An ultrastructural study of casts.

The microscopic lymphatics of the lung can be cast and studied with scanning electron microscopy. This technique shows several different forms of lymphatics and the interstitial space that leads into lymphatics as no other method can. To study changes in lymphatic forms, rats were placed in 85% oxygen for 7 days to produce pulmonary edema. Methyl methacrylate resin was injected into the lung vasculature at various times after the animals were removed from hyperoxia. In the animals not exposed to hyperoxia, no artery, vein, or airway was surrounded by a lymphatic cast. However, in rats that were in the hyperoxic chamber, 22% of arteries, 30% of veins, and 51% of indeterminate blood vessels (which could be arteries or veins) were encompassed by saccular lymphatic casts. These lymphatics were still observed 7 days after recovery from hyperoxia. Fourteen days after hyperoxia, the lymphatics returned to control values. Only 9% of the pleural surface of the animals not exposed to hyperoxia had initial lymphatics. Fifty-two percent of the hyperoxia-exposed animals had initial lymphatics, measured 3 days after exposure. This decreased to 14% 14 days after exposure to hyperoxia (P < 0.01). Conduit lymphatics were found on the pleural surfaces of 33% of animals exposed to ambient air and 100% of animals exposed to the high-oxygen environment (P < 0.05). The median percentage of the pleural surface covered with lymphatics was 0 in the animals exposed to ambient air. It was 65% in animals exposed to hyperoxia, 3 days after returning to room air. It was again 0 in animals exposed to hyperoxia, 14 days after returning to room air (P < 0.001). The lymphatics around veins expanded more than around arteries (P < 0.0001). These results indicate that in the rat all compartments of the lung lymphatics expand after the injury and edema caused by oxygen and return to normal with the resolution of the edema.     

Antibasement membrane disease. II. Mechanism of glomerular injury in an accelerated model of Masugi nephritis.

Rabbits were given injections of preformed complexes of purified goat antirabbit glomerular basement membrane antibody and rabbit antigoat immunoglobulin. When the animals were killed 24 hours later, examination of their kidneys revealed diffuse glomerulonephritis with widespread areas of localized loop necrosis, associated with extensive accumulations of polymorphonuclear leukocytes. By electron microscopy, accumulations of polymorphonuclear leukocytes in various degrees of disintegration were associated with areas of the basement membrane that appeared to be losing their structural integrity, suggesting that the damage to the membrane was brought about by the action of lysosomal enzymes. Reduction of the number of circulating polymorphonuclear leukocytes by pretreatment of the animals with nitrogen mustard completely prevented the lesions. Reduction of circulating complement levels by pretreatment of the animals with cobra venom factor prevented the occurrence of localized necrosis but allowed the development of the diffuse lesion.     

The development of bleomycin-induced pulmonary fibrosis in neutrophil-depleted and complement-depleted rats.

The development of bleomycin-induced pulmonary fibrosis was studied in rats depleted of neutrophils for 1 week and in rats depleted of complement for 1 week. Lung injury was assessed by histologic evaluation and by the biochemical measurement of total lung collagen. Qualitatively, histologic evidence of damage induced by bleomycin showed that damage progressed in a similar manner in neutropenic and complement-depleted animals when compared with normal animals. However, analysis of total lung collagen at 1 week after bleomycin administration revealed that collagen deposition was increased in neutropenic animals and decreased in animals depleted of complement when compared with untreated animals that received bleomycin. There were no significant differences in lung collagen levels at 1 month after bleomycin treatment in neutrophil-depleted or complement-depleted animals when compared with animals that received bleomycin alone.     

Experimental Salmonella typhimurium infections in rats. III. Transfer of immunity with primed lymphocyte subpopulations

The protective effect of primed lymphocytes against a lethal dose of Salmonella typhimurium was studied in athymic and euthymic LEW rats. Primed lymphocytes were obtained by inoculating euthymic and thymus-grafted animals with a non-lethal dose of Salmonella typhimurium. Four weeks after the infection, spleen lymphocytes were separated by panning technique and antibody-coated magnetic microsphere separation using antibodies to pan T and pan B lymphocytes and subsequent sorting in a fluorescence activated cell sorter by means of monoclonal antibodies against CD4+ and CD8+ cells. Euthymic and athymic rats were injected with different doses of primed pan B, pan T, CD4+ and CD8+ T lymphocytes before inoculation with a lethal bacterial dose. Most of the animals treated with pan B, pan T or CD8+ cells died within two weeks. After treatment with primed CD4+ cells, only six of 39 animals died. Doses as low as 10(4) cells from both euthymic or thymus-grafted animals were effective, and athymic and euthymic recipients survived equally well. Four weeks after the infection both athymic and euthymic animals housed very few bacteria and had high antibacterial antibody titres. The percentages of splenic and lymph node CD4+ cells in the athymic rats were comparable to those found in the euthymic animals. The study shows that primed CD4+ lymphocytes even in very low doses are able to induce immunity against a Salmonella typhimurium infection.     

Age-dependent gene induction in quail oviduct. IX. Age-dependent alterations of DNA-bound amino acids.

DNA-amino acids (and DNA-protein) complexes were isolated from oviducts of immature, mature and senescent quails by a procedure which does not involve proteolytic enzymes. The content of DNA-amino acids in the complexes, isolated from animals belonging to three different age classes is almost identical and it amounts to about 10 micrograms/mg DNA. However, the fraction of DNA-amino acids which is resistant to pronase is twice as high in lysates from senescent quails as in those from immature and mature animals. The amount of DNA-bound amino acids is strongly dependent on hormone-induced physiological effects in immature quails. If immature animals were treated with estrogen hormone, which causes in induction both of DNA and RNA synthesis, the level of DNA-bound amino acids increases by 220%. This material has been found to be pronase sensitive which might indicate that the amino acids are present as peptides. Treatment of estrogen-stimulated animals with progesterone or inhibitors of DNA and RNA synthesis antagonizes the estrogen-envoked formation of DNA-associated amino acids. From the data we propose that the amount of proteins and/or amino acids, bound to DNA,is not only age-related but also correlated with the physiological state of DNA in immature and mature animals.     

Jos virus infection in domestic animals and primates. Pathogenicity and immunological studies.

Three species of domestic animals (rabbits, sheep and goats) and two species of primates Erythrocebus patas monkeys and baboon (Papio anubis) were infected with Jos virus. None of the infected animals developed viraemia or overt clinical disease. Complement-fixing and neutralising antibodies were demonstrated in sera of infected animals.     

Antibiotics in acrylic bone cement. In vivo studies.

In vivo experiments were performed to study elution rates of antibiotics combined with Surgical implex bone cement and efficacy in controlling bacterial infections. Cylinders of bone cement were implanted in animals and at the same time the surgical areas were infected with large numbers of bacteria. Gentamicin and Keflin were eluted from the cylinders in sufficient quantities to completely eliminate or markedly reduce the number of bacteria recovered from infected areas. Animals were also treated with an anti-inflammatory drug, hydrocortisone, prior to implantation of cylinders and infection. The antibiotics in the bone cement effectively destroyed the bacteria in these animals with impaired inflammatory responses as compared with control animals.