Focus on anti-atherosclerotic therapy

Calcium antagonists (CA) exert an anti-atherosclerotic effect in cholesterol-fed rabbits through reduction of cholesterol accumulation in the arterial wall. Further studies in our Institute indicate that verapamil-like compounds and diltiazem stimulate receptor-mediated LDL uptake by human fibroblasts in culture, while nifedipine-like compounds and flunarizine are inactive. Verapamil and diltiazem stimulated LDL-receptor activity also in cells from a heterozygous FH patient, while they were inactive in a receptor defective homozygous FH patient. A basic group needs to be present on the CA molecule to modulate the LDL receptor expression. Preliminary data in our laboratory suggest that some CA can achieve concentrations in the aortic wall likely to exert effects on LDL receptors. This stimulatory activity may improve lipid metabolism in the arterial wall.Corresponding author     

Experimental axonopathy induced by immunization with campylobacter jejuni lipopolysaccharide from a patient with guillain‐barré syndrome

Campylobacter jejuni (C. jejunj) infection is the most common antecedent in the axonal variant of Guillain‐Barré syndrome (GBS). Antibodies against nerve gangliosides found in GBS patients recognize cross‐reactive epitopes in the lipopolysaccharide (LPS) of C. jejuni. This led to the molecular mimicry hypothesis of GBS. We immunized eleven rabbits with a LPS extracted from HS:19 C. jejuni strain isolated from a patient with GBS and complete Freund's adjuvant (CFA)(group I). In a second experiment we immunized seven rabbits with LPS, CFA and keyhole limpet hemocyanin (KLH)(group II). All group I rabbits developed high titers of anti‐LPS, anti‐GM1, anti‐GD1b antibodies and lower titers of anti‐GD1a. One rabbit, 50 days after initial inoculation, showed tremor and weakness. All rabbits of group II developed high titres of antiganglioside antibodies and six animals showed weakness 59–113 days after initial inoculation. Two rabbits died. Pathology showed mild to moderate, tendentially grouped, axonal degeneration in sciatic nerves of four out of five animals. Control rabbits of group I (immunized with CFA only) did not develop antibodies, controls of group II (immunized with CFA + KLH) developed low titers of IgG anti‐GM1. None developed neurological signs or showed axonal degeneration. C. jejuni LPS is a potent B‐cell stimulator capable to induce a strong antiganglioside response in rabbits. However, to induce the neuropathy is crucial to employ KLH, a glycoprotein known to stimulate both humoral and cellular responses. This animal model reproduces the pathogenetic process hypothesized in axonal GBS with antiganglioside antibodies post C. jejuni infection.     

Disorders of perfusion of the anterior segment of the eye

Background: We have investigated the vascular perfusion of a wide variety of conditions of the anterior segment using fluorescein angiography.
Methods: The conditions were classified and findings reported according to the system set out below. Patients underwent full ocular examination. Fluorescein angiography of the anterior segment was carried out when indicated to investigate iris atrophy and neovascularisation. Specular microscopy of the corneal endothelium was used to detect changes in this tissue.
Results: The hypoperfusion was variable in degree and accompanied by varying degrees of iris hypoplasia and atrophy with neovascularisation. The degree of neovascularisation depended upon its rapidity of development, the pre-existing state of vascular perfusion and the underlying pathological condition.
Conclusions: Hypoperfusion with resultant ischaemia and neovascularisation is common in conditions of the anterior segment. An understanding of the changes is valuable in treating many conditions affecting the anterior segment. The changes observed may also occur elsewhere in the physical system and may be a significant part of the ageing process, either as scattered, disparate processes or as part of a general disease process.     

Postoperative radiation therapy in the management of lung cancer

Postoperative radiation therapy for lung cancer is still controversial. In a 9-year period, 69 patients with non-oat-cell carcinoma of the lung (16% stage I, 26% stage II, and 58% stage III) received such therapy. The radiation dose was less than 5,000 cGy in 42 patients, 5,000-5,900 cGy in 16, and 6,000 cGy or more in 11; follow-up ranged from 24 to 64 months. Actuarial survival at 2 and 4 years was 50% and 16%, respectively, for squamous cell carcinoma, and 40% and 26% for adenocarcinoma. The 5-year survival for stages I, II, and III cancer was 29%, 17%, and 19%, respectively. Histologic findings and type of surgery did not affect survival, but the radiation dose apparently did. The 3-year survival for patients who received less than 6,000 cGy was 35%, compared with 73% for patients who received higher doses. In eight patients, treatment failed within the irradiated volume: all had received doses of less than 6,000 cGy, and the volume in three was judged to be inadequate.     

An analysis of invasive airway management in a suburban emergency medical services system

INTRODUCTION: Airway management is the most critical and potentially life-saving intervention performed by emergency medical service (EMS) providers. Invasive airway management often is required in non-cardiac-arrest patients who are combative or otherwise uncooperative. The success of prehospital invasive airway management in this patient population was evaluated. METHODS: A retrospective review was undertaken of the records of all such patients requiring endotracheal intubation over a three-year period (1987-1989). The study population included 278 patients enrolled by five advanced life support (ALS) units serving a suburban population of 425,000. Field trip sheets were reviewed for diagnosis, intubation method and success, number of intubation attempts, provider experience, reasons for unsuccessful intubations, and complications. RESULTS: A total of 394 invasive airway management attempts were performed on 278 patients. The overall successful intubation rate was 75% (41% orotracheal, 52% nasotracheal, 7% other or unknown). The most common diagnoses were COPD and pulmonary edema (30%) and trauma (24%). Experienced providers were successful on the first attempt in 57% of cases compared to 50% by inexperienced providers (p=.24). Multiple intubation attempts were required in 33% of the patients. There was no statistically significant difference in success rates between the orotracheal and nasotracheal methods (p=.51). The most common reason for unsuccessful intubation was altered level of consciousness. Complications occurred with 7% of successful attempts and in 18% of unsuccessful attempts (p less than .001). Forty-six percent of the patients who were not intubated successfully in the field and required intubation in the emergency department (ED) received a neuromuscular blocking agent prior to successful intubation. CONCLUSION: Prehospital providers can intubate a high but improvable proportion of non-cardiac-arrested patients by both the orotracheal and nasotracheal routes. The use of pharmacologic adjuncts to facilitate the prehospital intubation of selected, non-cardiac-arrested patients is a promising adjunct that needs further evaluation.     

Normal human IgG prevents endothelial cell activation induced by TNFalpha and oxidized low-density lipoprotein atherogenic stimuli

Normal human immunoglobulin G (IgG) has anti-inflammatory and immuno-regulatory properties, which are exploited in the therapy of selected diseases. A putative mechanisms of action is the direct regulation of endothelial cell function by natural antiendothelial cell antibodies. Endothelium activation is a critical event in atherosclerosis. We have verified the ability of normal human IgG to modulate endothelial responses to the atherogenic stimuli tumour necrosis factor-alpha (TNFalpha) and oxidized low-density lipoproteins (oxLDL) in vitro. Confocal microscopy was used to visualize vascular cell adhesion molecule-1 (CD106) expression on endothelial cells, cytoplasmic free calcium ([Ca++]i) modifications and fluorescein-coupled oxLDL internalization. Cytokine secretion was measured by ELISA on cell supernatants. IgG prevented TNFalpha induced CD106 membrane expression and an increase in [Ca++]i, and inhibited the secretion of interleukin-6 (IL-6) and macrophage-colony-stimulating factor (M-CSF). IgG also inhibited CD106 expression induced by oxLDL and one pathway of their internalization, but were ineffective on oxLDL induced [Ca++]i rise and apoptosis. F(ab)'2 fragments from IgG, but not monoclonal IgG, reproduce IgG effects. These findings point to a regulatory role for specific antibodies included in circulating normal IgG towards proinflammatory responses of endothelial cells in atherogenesis and suggest possible development of new therapeutic strategies.     

Dendritic cell number is related to IL-4 expression in the airways of atopic asthmatic subjects

BACKGROUND: Airway dendritic cells are essential for stimulating naive T cells in response to inhaled antigen and for the development of allergic sensitization. IL-4 in vitro can distinguish dendritic cell lines from peripheral blood mononuclear cells. Our study had the following aims: 1) to compare the distribution of CD1a+ dendritic cells and IL-4+ cells, in the bronchial mucosa of asthmatics and controls 2) to determine the relationship between the numbers of CD1a+ dendritic cells and IL-4+ cells in the bronchial mucosa of asthmatics 3) to determine whether CD1a+ cells express the IL-4 receptor. METHODS: Twenty atopic asthmatic and eight normal subjects were studied. In each subject, bronchoscopy with bronchial biopsies was performed. CD1a, IL-4, and IL-4 receptor expressions were evaluated by immunohistochemistry. RESULTS: The number of CD1a+ and IL-4+ cells was significantly higher in asthmatics than controls. The number of CD1a+ cells was positively correlated to the number of IL-4 + cells. Bronchial biopsy serial section studies showed that CD1a+ cells express the receptor for IL-4. CONCLUSIONS: These results suggest that an increased amount of IL-4 may play a physiopathologic role in maintaining the dendritic cell pool in vivo. Therefore, because of possible IL-4 activity on antigen-presenting cells in T-cell immune responses to allergens, an important new role of IL-4 in asthma inflammation can be envisaged.