Suppression of the immune system by oral glucocorticoid therapy in bronchial asthma

The effect of systemic glucocorticoid therapy on immune parameters was studied in patients with bronchial asthma. Patients were divided into two groups: 1) those receiving oral glucocorticoid; 2) control patients who did not receive systemic glucocorticoid treatment. The glucocorticoid dose varied between 5 and 70 mg per day. Patients had been taking oral therapy for at least 1 year. Glucocorticoid treatment was associated with an increased frequency of respiratory tract infections. Therefore, we need to define immune parameters which may predict an increased risk of infections. In this study, we analyzed several surface markers on lymphocytes and monocytes by flow cytometry. A significant reduction of the ratio of peripheral blood CD4⁺ to CD8⁺ T cells was associated with the administration of oral glucocorticoids. Furthermore, the expression of the HLA-DR molecule on monocytes was reduced in patients with systemic glucocorticoid therapy compared to control patients. Moreover, the capacity to elaborate cytokines by peripheral blood mononuclear cells upon stimulation was greatly reduced after exposure to glucocorticoids in vivo and in vitro. In addition, the humoral immune response was affected, because reduced IgG, IgM, and IgA levels were observed in patients receiving oral glucocorticoids. These results indicate that systemic glucocorticoid treatment in patients with bronchial asthma is associated with cellular and humoral immunosuppression which results in an increased risk of bacterial and viral infections.     

Double-stranded RNA and bacterial lipopolysaccharide enhance sensitivit to TNF-{alpha}-mediated cell death

The effect of double-stranded RNA (dsRNA) and bacterial lipopolysaccharideon the sensitivity to tumor necrosis factor (TNF)--medlatedcell death was studied In an In vitro system. Since secretionof TNF- Is a part of the early host response to viral and bacterialinfection, we examined whether mimicking the Infection withviral and bacterial products could affect the response of cellsto TNF-. Incubation of WEHI 164 fibrosarcoma cells with dsRNAor lipopolysaccharide (LPS) significantly increased their sensitivityto TNF--mediated lysis and to TNF-secreting inflammatory T cell-mediatedlysis. Thus, these products could induce Increased sensitivityto TNF- In cells In an inflammatory focus, possibly contributingto selective elimination of Infected but not healthy cells bythis non-specific cytokine. Additionally, our data show thatboth dsRNA and LPS, as well as TNF- Itself, rapidly Induce nuclearfactor-xB (NF-*B), a DNA-bindlng protein Implicated In regulationof gene expression. We suggest that NF-xB could regulate genescrucial for the induction of cell death by TNF-.     

Use of a new mixture for embolization of intracranial vascular malformations

Summary The internal carotid artery system in swine has a special anatomic configuration similar to a brain arterial-arterial malformation. The internal carotid artery breaks up into a multitude of fine channels (rete mirabile) situated at the base of the skull on the side of the hypophysis. This anatomic arterial model was used to analyze acute and chronic angiographic and histological changes after occlusion of the rete mirabile with I) avitene, II) avitene, and 50% ethanol, III) avitene, 30% ethanol and Polyvinyl alcohol, IV) avitene 50% ethanol and Polyvinyl alcohol, V) IBCA and VI) silk. Histopathological changes observed in the rete mirabile six weeks following occlusion demonstrated that a mixture of avitene, 30% ethanol and Polyvinyl alcohol and IBCA produced the best anatomic results. Embolization with avitene, PVA and ethanol induced a more bland histological reaction than the one observed with IBCA. Preliminary clinical experience with this mixture is reassuring in those cases in which the AVM was surgically resected. The partially thrombosed AVM was easily depressed and compressed by the neurosurgeon allowing for satisfactory hemostasis in and around the nidus of the AVM.This paper was presented in part at the International Symposium on Cerebral Stroke, Sendai, Japan, 1987     

Combined treatment of pelvic exenterative surgery and intra-operative pelvic hyperthermochemotherapy for locally advanced rectosigmoid cancer: Report of a case

A huge rectosigmoidal cancer which extended into the urinary bladder in a 64-year-old man is herein described. The tumor occupied the pelvic and lower abdominal cavities, while the rectosigmoid was totally obstructed. No hepatic or pulmonary metastasis was evident. The ventral and flank sides of the peritoneum in the right lower abdomen, right common iliac vessels, bilateral ureters, terminal ileum, cecum, ascending colon, and urinary bladder were all directly invaded by the tumor, but the aorta, sacrum, and lower rectum were free of cancer. Consequently, an anterior pelvic exenteration was carried out along with an ileal conduit and a right hemicolectomy. Immediately after the exenteration, intra-pelvic hyperthermochemotherapy was performed using a 46–47°C perfusate containing 40 g/ml of mitomycin C (MMC) and 200 g/ml of cisplatin (CDDP), for 90 min, in an attempt to prevent any further local recurrence. A right hemicolectomy and a permanent colostomy were done simultaneously with the hyperthermia treatment. After an uneventful postoperative course, the patient was prescribed adjuvant chemotherapy, i.e., two administrations of 17 mg/m² and 21 mg/m² of MMC, and ten doses of 710 mg/m² of 5-fluorouracil (5-FU) followed by five doses of 535 mg/m² of 5-FU. At the time of this writing, the patient is still alive without recurrence at 21 months after surgery.     

A Clinicopathologic Series of 22 Cases of Tonsillar Granulomas

Objectives Tonsils are uncommonly affected by granulomatous inflammation, often with an obscure cause. This study attempts to elucidate the nature of tonsillar granulomatous inflammation. Design Retrospective clinicopathologic review. Methods Twenty‐two cases of tonsillar granulomas diagnosed between 1940 and 1999 were retrieved from the files of the Armed Forces Institute of Pathology. H&E slides and a series of histochemical stains were reviewed, and patient follow‐up was obtained. Results There were 11 males and 11 females, aged 7 to 64 years (mean, 29.9 y). Most of the cases presented bilaterally (n = 19) with sore throat, dysphagia, and/or nasal obstruction. The clinical differential included chronic tonsillitis, tuberculosis, nonspecific infection, sarcoidosis, and a neoplasm. Histologically, the granulomas were focal and scattered, or diffuse, identified in the interfollicular zones (n = 16) and/or the germinal centers (n = 13), and occasionally associated with necrosis (n = 6). Based on histochemical and clinical follow‐up information, the etiology of the granulomas included sarcoidosis (n = 8), tuberculosis (n = 3), Hodgkin's lymphoma (n = 2), toxoplasmosis (n = 1), squamous cell carcinoma (n = 1), and no specific known cause (n = 7). Twelve patients were either alive at last follow‐up or had died with no evidence of disease (mean, 12.4 y), and 9 were either alive at last follow‐up or had died with disease (mean, 24.9 y). One patient was alive with unknown disease status (lost to follow‐up after 13.3 y). Conclusions Although a cause for tonsillar granulomas is frequently identified, a number may not develop an identifiable etiology, with the granulomas probably representing an exaggerated immune response to chronic tonsillitis. However, a careful work‐up must be conducted to exclude specific causes and avoid clinical mismanagement.     

The effect of the selectin binding polysaccharide fucoidin on eosinophil recruitment in vivo

1. In order to accumulate at sites of inflammation, leukocytes initially roll on endothelial cells of post-capillary venules before becoming firmly attached. This process of rolling is mediated by selectins which bind to carbohydrate counter-ligands present on the surface of both leukocytes and endothelial cells. The polysaccharide fucoidin has been previously shown to inhibit leukocyte rolling in the mesenteric circulation and to reduce neutrophil accumulation in the skin and meninges in experimental inflammation.
2. In the present study we have assessed the effects of fucoidin on eosinophil function in vitro and eosinophil accumulation at sites of inflammation in guinea-pig skin.
3. At concentrations of up to 1200 μg ml⁻¹, fucoidin inhibited phorbol myristate acetate (PMA)-induced eosinophil homotypic aggregation by up to 60% but had no inhibitory effect on PMA-induced eosinophil adhesion to serum-coated plates.
4. Fucoidin effectively reduced the binding of the anti-L-selectin mAb MEL-14 to guinea-pig eosinophils. Binding of a P-selectin-IgG chimera to eosinophils was also partially inhibited by fucoidin, but binding of an anti-CD18 or an anti-VLA-4 mAb were unaffected.
5. When given systemically to guinea-pigs, fucoidin suppressed ¹¹¹In-labelled eosinophil recruitment to sites of allergic inflammation. ¹¹¹In-labelled eosinophil accumulation induced by platelet-activating factor (PAF) and zymosan-activated plasma (as a source of C5a des Arg) was also inhibited.
6. These results demonstrate a role for fucoidin-sensitive selectins in mediating eosinophil recruitment in vivo.

     

Inhibition of neutrophil and monocyte recruitment by endogenous and exogenous lipocortin 1

1. The role played by endogenous lipocortin 1 in the anti-migratory action exerted by dexamethasone (Dex) on monocyte recruitment in an in vivo model of acute inflammation was investigated by use of several neutralizing polyclonal antibodies raised against lipocortin 1 or a lipocortin 1-derived N-terminus peptide (peptide Ac2-26). The efficacy of peptide Ac2-26 in inhibiting monocyte and polymorphonuclear leucocyte (PMN) recruitment was also tested.
2. Intraperitoneal (i.p.) injection of zymosan A (1 mg) produced a time-dependent cell accumulation into mouse peritoneal cavities which followed a typical profile of acute inflammation: PMN influx was maximal at 4 h post-zymosan (between 15 and 20×10⁶ cells per mouse), and this was followed by an accumulation of monocytes which peaked at the 24 h time-point (between 10 and 15×10⁶ cells per mouse).
3. Dex administration to mice reduced zymosan-induced 4 h PMN infiltration and 24 h monocyte accumulation with similar efficacy: approximately 50% of inhibition of recruitment of both cell types was achieved at the dose of 30 μg per mouse (∼1 mg kg⁻¹, subcutaneously (s.c.)). Maximal inhibitions of 64% and 67% on PMN and monocyte recruitment, respectively, were measured after a dose of 100 μg per mouse (∼3 mg kg⁻¹, s.c.).
4. Dex (30 μg s.c.) inhibited monocyte (53%) and PMN (69%) accumulation in response to zymosan application in mice which had been treated with a non-immune sheep serum (50 μl s.c.). In contrast, the steroid was no longer active in reducing cell accumulation in mice which had been passively immunized against full length human recombinant lipocortin 1 (serum LCS3), or against lipocortin 1 N-terminus peptide.
5. Treatment of mice with vinblastine (1 mg kg⁻¹, intravenously (i.v.)) produced a remarkable leucopenia as assessed 24 h after administration. This was accompanied by a 60% reduction in 4 h-PMN influx, and by a 27% reduction in 24 h-monocyte accumulation, measured after zymosan administration. The inhibitory effect of Dex on monocyte recruitment was not significantly modified in vinblastine-treated mice, with 36% and 57% of inhibition calculated at the dose of 30 μg Dex, and 70% and 60% of inhibition at 100 μg Dex, in vehicle- and vinblastine-treated mice, respectively.
6. Treatment of mice with peptide Ac2-26 dose-dependently attenuated PMN influx at 4 h post-zymosan with a significant effect at 100 μg per mouse (45% of inhibition, n=9, P<0.05) and a maximal effect of 61% inhibition at the highest dose tested of 200 μg s.c. (n=14, P<0.05). No effect of peptide Ac2-26 (200 μg s.c.) was seen on zymosan-induced 24 h monocyte recruitment. In contrast, administration of 200 μg peptide Ac2-26 every 6 h was effective in reducing the number of monocytes harvested from the inflamed peritoneal cavities at 24 h post-zymosan: 9.40±0.58×10⁶ monocytes per mouse (n=13) and 5.74±0.34 monocytes per mouse (n=14) in vehicle- and peptide Ac2-26-treated mice, respectively (P<0.05).
7. Finally, peptide Ac2-26 produced a concentration-dependent inhibition of the rate of phagocytosis of mouse resident peritoneal macrophages as measured by flow cytometry, with a maximal reduction of 34% at the highest concentration tested of 100 μg ml⁻¹ (n=8 experiments performed in duplicate; P<0.05).
8. In conclusion, this study suggests that in vivo monocyte recruitment during acute inflammation is, at least in part, under the negative modulatory control of endogenous lipocortin 1 (as seen after administration of Dex by using the specific antisera) and exogenous lipocortin 1 mimetics (as observed with peptide Ac2-26). In addition to the neutrophil, we can now propose that the monocyte also can be a target for the in vivo anti-inflammatory action of lipocortin 1.

     

Differential roles of neurokinin 1 and neurokinin 2 receptors in the development and maintenance of heat hyperalgesia induced by acute inflammation

1. Following induction of acute inflammation by intraarticular injection of kaolin and carrageenan into the knee joint in rats, there was a significant decrease in the withdrawal latency to radiant heat applied to the paw (i.e. heat hyperalgesia), an increased joint circumference and increased joint temperature.
2. A neurokinin₁ (NK₁) receptor antagonist (CP-99,994, 10 mM) had no effect on the paw withdrawal latency when it was administered spinally through a microdialysis fibre before the induction of inflammation. Pretreatment with a NK₂ receptor antagonist (SR48968, 1 mM) administered spinally through the microdialysis fibre prevented the heat hyperalgesia from developing in the early stages of the inflammation.
3. Post-treatment through the microdialysis fibre with the NK₁ receptor antagonist (0.0110 mM) was effective in reversing the heat hyperalgesia. In contrast, post-treatment spinally with the NK₂ receptor antagonist (0.011 mM) had no effect on the heat hyperalgesia. The inactive stereoisomers of the NK₁ receptor antagonist, CP100,263, or the NK₂ receptor antagonist, SR48965, administered at the same doses, had no effect on the joint inflammation or the heat hyperalgesia.
4. Pretreatment systemically with the NK₁ receptor antagonist (30 mg kg⁻¹) had no effect on the heat hyperalgesia or pain-related behaviour ratings where 0 is none and 5 is non weight bearing and complete avoidance of limb contact. Pretreatment with a NK₂ receptor antagonist (10 mg kg⁻¹) systemically prevented the heat hyperalgesia and pain-related behaviour ratings from developing in the early stages of the inflammation. The inactive stereoisomers of NK₁ receptor antagonist, CP100,263, or the NK₂ receptor antagonist, SR48965, administered at the same doses, had no effect on the joint inflammation or the heat hyperalgesia.
5. Post-treatment systemically with either the NK₁ (0.130 mg kg⁻¹) or the NK₂ (0.110 mg kg⁻¹) receptor antagonist resulted in a dose-dependent reversal of the heat hyperalgesia. Pain-related behaviour ratings were reduced by post-treatment only with the NK₁ receptor antagonist. The inactive stereoisomers of the NK₁ receptor antagonist, CP100,263, or the NK₂ receptor antagonist, SR48965, administered at the same doses, had no effect on the behavioural responses.
6. Direct pretreatment of the knee joint with either the NK₁ (30 mg) or the NK₂ (10 mg) receptor antagonist prevented the heat hyperalgesia from developing without affecting joint swelling. The inactive stereoisomers of the NK₁ receptor antagonist, CP100,263, or the NK₂ receptor antagonist, SR48965, administered at the same doses, had no effect on the joint inflammation or the heat hyperalgesia.
7. There appears to be a differential role for the spinal tachykinin receptors in the development and maintenance of the heat hyperalgesia associated with acute joint inflammation. The NK₂ receptors appear to be activated early in the development of the heat hyperalgesia and NK₁ receptors are involved in the maintenance of the heat hyperalgesia.
8. Peripherally, both NK₁ and NK₂ receptors are involved in the development of heat hyperalgesia and pain-related behaviour ratings induced by acute inflammation.

     

The inflammatory lesion of T cell line transferred experimental autoimmune encephalomyelitis of the Lewis rat: distinct nature of parenchymal and perivascular infiltrates

We have investigated the T cell receptor (TCR) repertoire in the inflammatory infiltrates of T line-transferred experimental autoimmune encephalomyelitis (EAE) of the Lewis rats. Using a panel of TCR V-specific monoclonal antibodies (mAbs) and immunocytochemistry, we studied the nature of the T cells entering the central nervous system (CNS) after transfer of either myelin basic protein (MBP)-reactive, or MBP-reactive but non-encephalitogenic T cell lines. All the MBP-specific T cell lines predominantely used the V8.2 TCR chain. T cell lines specific for the tuberculin purified protein derivative (PPD), using TCR V genes different from V8.2, served as controls. We first studied the time course of T cells entering the CNS. In all recipient rats, small, but significant numbers of -TCR-expressing infiltrate cells appeared in the CNS within the first 24 h after T cell transfer. In animals injected with either type of MBP-reactive T cells, the early infiltrate cells were preferentially located within the parenchyma of the spinal cord, while in PPD T lineinjected rats, the lymphocytes were mostly found in the meninges. TCR V gene usage was examined on the peak of clinical disease. Six days after T cell transfer, the TCR repertoire used by infiltrating lymphocytes in general seemed to be highly diverse. None of the V isotypes examined (i.e. V8.2, V8.5 or V10) was used by a major population of the -TCR-positive T cells. A more detailed, quantitative analysis of individual infiltrate compartments revealed, however, a preferential accumulation of V8.2-positive T cells within the parenchyma. In contrast, perivascular infiltrating cells used V genes randomly. Our results confirm first that activated T lymphocytes enter the brain rapidly irrespective of their antigen specificity. Second, the data show that most of the perivascular infiltrate T cells in the acute EAE lesion are host-derived, recruited presumably from the recirculating T cell pool, while the encephalitogenic, V8.2-positive T cells preferentially persist within the parenchyma.Abbreviations EAE experimental autoimmune encephalomyelitis - MBP myelin basic protein - TCL T cell line Supported by the Brazilian Research Council (CNPq)