Allergic disease in 8-year-old children is preceded by delayed B cell maturation.

BACKGROUND: We previously reported that exposure to a farming environment is allergy-protective, while high proportions of neonatal immature/naïve CD5+ B cells and putative regulatory T cells (Tregs) are risk factors for development of allergic disease and sensitization up to 3 years of age. OBJECTIVE: To examine if B and T cell maturation are associated with allergic disease and farming environment over the first 8 years in life. METHODS: In the prospective FARMFLORA study, including both farming and non-farming families, 48 of 65 children took part in the 8-year follow-up study. Various B and T cell maturation variables were examined in blood samples obtained at several occasions from birth to 8 years of age and related to doctors' diagnosed allergic disease and sensitization, and to farming environment. RESULTS: We found that the incidence of allergic disease was lower among farmers' compared to non-farmers' children during the 8-year follow-up period, and that farmers' children had higher proportions of memory B cells at 8 years of age. Moreover, a high proportion of neonatal CD5+ B cells was a risk factor for and may predict development of allergic disease at 8 years of age. A high proportion of Tregs was not protective against development of these conditions. CONCLUSION AND CLINICAL RELEVANCE: High proportions of neonatal naïve B cells remained as a risk factor for allergic disease in school-aged children. Thus, the accelerated B cell maturation observed among farmers' children may be crucial for the allergy-protective effect of a farming environment.

High proportions of FOXP3(+) CD25(high) T cells in neonates are positively associated with allergic sensitization later in childhood.

BACKGROUND: The role of FOXP3(+) regulatory T cells in the prevention against sensitization and allergy development is controversial. OBJECTIVE: We followed 65 newborn Swedish children from farming and non-farming families from birth to 3 years of age and investigated the relation between CD4(+) T cell subsets in blood samples and development of sensitization and allergic disease. METHODS: The proportions of FOXP3(+) CD25(high) , CTLA-4(+) CD25(+) , CD45RO(+) , HLA-DR(+) , CCR4(+) or α4ß7(+) within the CD4(+) T cell population were examined by flow cytometry of blood samples at several time-points. Mononuclear cells were isolated from blood and stimulated with birch allergen, ovalbumin or the mitogen PHA, and the levels of IL-1ß, IL-6, TNF, IFN-γ, IL-5 and IL-13 were measured. A clinical evaluation regarding the presence of allergen-specific IgE and allergy was performed at 18 and 36 months of age. RESULTS: Multivariate discriminant analysis revealed that children who were sensitized at 18 or 36 months of age had higher proportions of FOXP3(+) CD25(high) T cells at birth and at 3 days of life than children who remained non-sensitized, whereas allergy was unrelated to the neonatal proportions of these cells. The proportions of CTLA-4(+) CD25(+) T cells were unrelated to both sensitization and allergy. The association between higher proportions of FOXP3(+) CD25(high) T cells and sensitization persisted after exclusion of farmer's children. Finally, a farming environment was associated with lower proportions of FOXP3(+) CD25(high) T cells in early infancy and to a more prominent T cell memory conversion and cytokine production. CONCLUSION & CLINICAL RELEVANCE: Our results indicate that high proportions of FOXP3(+) CD25(high) T cells in neonates are not protective against later sensitization or development of allergy.

High circulating immunoglobulin A levels in infants are associated with intestinal toxigenic Staphylococcus aureus and a lower frequency of eczema.

BACKGROUND: Intestinal bacteria trigger IgA production and delayed maturation of mucosal IgA response is linked to allergy development. OBJECTIVE: Our aim was to investigate if plasma levels of IgA or APRIL (a proliferation inducing ligand), an important factor for IgA class switch recombination, in infancy correlates with intestinal colonization by any specific bacteria or yeast. We also examined if plasma IgA or APRIL levels are related to sensitization and the development of eczema. METHODS: IgA was quantified in plasma obtained from infants at birth and at 4 and 18 months of age and APRIL was measured at 4 months of age. Colonization by major bacterial groups and yeast was followed in the first 8 weeks of life by quantitative culture of stool samples. A clinical evaluation regarding the presence of allergen-specific IgE or eczema and eosinophil counts in blood was performed at 18 months of age. RESULTS: In multiple linear regression analysis, only colonization by Staphylococcus aureus strains producing toxins with superantigen function (SEA-D or TSST-1) made an independent contribution to plasma IgA levels at 4 months of age. Further, increased levels of APRIL in plasma at 4 months were negatively associated with sensitization while IgA plasma levels were inversely correlated to eczema development and blood eosinophil counts at 18 months of age. CONCLUSION: Early intestinal colonization by toxigenic S. aureus strains seems to promote systemic IgA responses. Furthermore, high levels of APRIL and IgA in the circulation at 4 months of age seem to correlate negatively with allergy development.

Can duplex arterial ultrasonography reduce unnecessary angiography?

OBJECTIVE: To assess the value of arterial duplex ultrasound, which assesses the location and severity of arterial disease, in determining whether invasive vascular intervention is required. METHOD: A total of 166 consecutive diabetic patients presenting at a multidisciplinary foot clinic with severe peripheral vascular disease, with or without a foot ulcer, were included in this prospective study. The choice of vascular intervention was based on the results of a duplex ultrasound examination. Subjects were followed up for two years, and their clinical management, vascular assessments and interventions given, and patient outcomes were recorded in a specially designed protocol. RESULTS: Based on findings of the duplex ultrasound, it was recommended that 55 patients (33%) should undergo angioplasty (percutaneous transluminal angioplasty [PTA] and/or subintimal recanalisation), 64 patients (39%) diagnostic angiography and 47 patients (28%) medical treatment only, thereby avoiding unnecessary angiography and its potential complications. Diagnostic angiography was recommended when the duplex ultrasound results were inconclusive. Fifty-two of the 55 patients recommended angiography with simultaneous angioplasty had an angiography; of these, 42 (81%) then had an angioplasty. Fifty-seven of the 64 patients with inconclusive results had an angiography. Of these, 23 (40%) subsequently had angioplasty, only 10 (18%) had reconstructive surgery and 24 (42%) had a diagnostic angiography only. CONCLUSION: Arterial duplex ultrasound may assist evaluations of the need for and type of invasive vascular intervention in patients with an ischaemic diabetic foot. It can thus help avoid diagnostic angiographies that do not result in vascular intervention. However, such decision-making remains at the discretion of the vascular surgeon and radiologist.

Reduction in vascular lesion formation by hirudin secreted from retrovirus-transduced confluent endothelial cells on vascular grafts in baboons.

BACKGROUND: The hypothesis that thrombin mediates the formation of neointimal vascular lesions at sites of mechanical vascular injury has been tested in baboons by measurement of the effects of hirudin delivered by retrovirus-transduced hirudin-secreting vascular endothelial cells (ECs) lining surgically implanted arterial vascular grafts (AVGs). METHODS AND RESULTS: The antithrombotic efficacy of baboon ECs transduced with cDNA encoding hirudin was assessed in vitro and in vivo on thrombogenic segments in chronically exteriorized femoral arteriovenous (AV) shunts. Bilateral brachial AVGs lined with hirudin-transduced versus nonhirudin control ECs at confluent density were surgically implanted, and vascular lesion formations at distal graft-vessel anastomoses were compared after 30 days. Hirudin-transduced ECs secreted 20+/-6 ng x 10(6) cells(-1) x 24 h(-1) (range, 14 to 24 ng x 10(6) cells(-1) x 24 h(-1)) hirudin in supernatants of static cultures. Hirudin-secreting ECs on segments of collagen-coated graft interposed in chronic AV shunts decreased the accumulation of (111)In-labeled platelets to 0.52+/-0.34 x 10(9) platelets, compared with 0.82+/-0.49 x 10(9) platelets in controls (P = 0.03) and reduced platelet deposition in propagated thrombotic tails extending downstream from segments of vascular graft from 1.38+/-0.41 x 10(9) platelets in controls to 0.59+/-0.22 x 10(9) platelets (P = 0.04). ECs recovered from 30-day AVG implants generated 17+/-9 ng x 10(6) cells(-1) x 24 h(-1) (range, 9 to 25 ng x 10(6) cells(-1) x 24 h(-1)) hirudin. Hirudin-secreting ECs reduced neointimal lesion formation at distal graft-vessel anastomoses, ie, 1.02 mm(2) (range, 0.88 to 1.95 mm(2)) versus 1.82 mm(2) (range, 0.88 to 2.56 mm(2)) in contralateral AVGs bearing nonhirudin control ECs (P<0.01). CONCLUSIONS: Viral vector-directed secretion of hirudin from ECs lining implanted AVGs significantly reduces the formation of thrombus and neointimal vascular lesions.

Localizing antithrombotic and vasodilatory activity with a novel, ultrafast nitric oxide donor.

Reaction of nitric oxide (NO) with L-proline in methanolic sodium methoxide yields a diazeniumdiolate product, C5H7N3O4Na2.CH3OH (PROLI/NO), that can be stabilized in basic solution but that dissociates to proline (1 mol) and NO (2 mol) with a half-life of only 1.8 s at pH 7.4 and 37 degrees C. This kinetic behavior has allowed the generation of highly localized antiplatelet and vasodilatory effects. By infusing solutions containing 4 microM PROLI/NO in 0.1 M sodium hydroxide at the rate of 1 nmol.min-1 immediately upstream from a polyester vascular graft in the unheparinized baboon circulatory system, for example, platelet deposition at the normally thrombogenic graft surface was substantially reduced relative to controls receiving only 0.1 M sodium hydroxide. In a second study, infusion of PROLI/NO into the right atrium of sheep with induced pulmonary hypertension selectively dilalated the lung vasculature, dose-dependently reducing the pulmonary arterial pressure by as much as 9 mmHg with no observable effect on the systemic arterial pressure at an infusion rate of up to 24 nmol.kg-1.min-1. PROLI/NO could also be formulated as an insoluble polymer blend that released NO smoothly for prolonged periods. The results suggest that localized delivery of diazeniumdiolates such as PROLI/NO which generate NO with extreme rapidity on entering the blood stream may hold considerable promise for inhibition of thrombus formation, selective dilation of the vasculature, and other research and clinical applications.

Isolated straight sinus and deep cerebral venous thrombosis: successful treatment with local infusion of urokinase. Case report.

A 23-year-old woman presented with headache and progressive lethargy. The diagnosis of isolated thrombosis of the straight sinus and of the deep cerebral venous system was established using cranial computerized tomography, magnetic resonance imaging, phase-contrast magnetic resonance venography, and cerebral angiography. Because of the rapid deterioration in the patient's clinical condition, the authors used direct transcatheter infusion of urokinase into the straight sinus. This treatment resulted in a successful outcome.

[Ruptured abdominal aortic aneurysm. Endovascular treatment under local anesthesia]. / Rupturerat bukaortaaneurysm. Endovaskulär behandling i lokalanestesi.

We report on endovascular repair of a ruptured abdominal aortic aneurysm. A bifurcated stent graft was inserted under local anesthesia. Aortic clamping is rapidly provided by percutaneous placement of an aortic occlusion balloon catheter. Carbon dioxide can usually replace conventional contrast in patients with renal insufficiency. This minimally invasive procedure may reduce perioperative morbidity and mortality in patients with ruptured aortic aneurysms. The advantages and limitations of this novel technique are discussed.

Increased levels of circulating soluble CD14 but not CD83 in infants are associated with early intestinal colonization with Staphylococcus aureus.

BACKGROUND: Soluble forms of the monocyte marker CD14 and the mature dendritic cell marker CD83 are plasma proteins with immunoregulatory functions. The physiological stimulus for their production is unclear and their possible role in allergy development is unknown. METHODS: We measured the plasma levels of soluble CD14 (sCD14) and soluble CD83 (sCD83) in 64 Swedish children in relation to intestinal bacterial colonization pattern in a prospective birth cohort. Soluble CD14 and sCD83 levels were quantified by enzyme linked immunosorbent assay in plasma obtained at birth and at 4, 18 and 36 months of age. All major aerobic and anaerobic bacteria were quantified in faecal samples obtained regularly over the first 8 weeks of life. Clinical allergy and IgE levels were evaluated at 18 months of age. RESULTS: Soluble CD14 in plasma increased during the first 18 months of life while sCD83 peaked at 4 months of age. Children who were perinatally colonized with Staphylococcus aureus had significantly higher levels of sCD14 in plasma at 4 months of age relative to non-colonized children. The levels of sCD14 were unrelated to colonization with Escherichia coli, other enterobacteria, enterococci, clostridia, Bacteroides, bifidobacteria or lactobacilli. Further, children with food allergy by 18 months tended to have lower levels of sCD14 than healthy children. Plasma levels of sCD83 were not related to either bacterial colonization pattern or allergy development. CONCLUSIONS: Perinatal colonization with S. aureus may trigger the occurrence of sCD14 in plasma, which may influence development of the infantile immune system and risk of allergy development.

Cat allergen induces proinflammatory responses by human monocyte-derived macrophages but not by dendritic cells.

BACKGROUND: The upper airway mucosa of healthy humans contains a dense network of cells with dendritic morphology of which the majority express a macrophage-like phenotype (CD14+CD64+CD68+), whereas the smaller population are immature dendritic cells (DC; CD11c+CD14-). Our aim was to study the proinflammatory response of human monocytes and in vitro-generated macrophages and DC after contact with cat allergens. METHODS: Monocyte-derived DC and monocyte-derived macrophages were exposed to cat allergen extract or Escherichia coli. Purified monocytes were stimulated with allergen extracts from cat or house dust mite (HDM) or the major allergenic protein Fel d 1 and induction of proinflammatory cytokines by monocytes was analyzed before and after blocking CD14. RESULTS: We show that cat allergen extract induced tumor necrosis factor (TNF) and interleukin (IL)-6 production by CD14-positive macrophages but not by CD14-negative DC. Moreover, monocytes produced significantly higher levels of TNF in response to cat allergens than in response to HDM allergens. We observed no differences in levels of TNF and IL-6 from either macrophages or monocytes after exposure to cat allergen when comparing healthy and cat-allergic individuals. Finally, the proinflammatory cytokine production from monocytes in response to cat allergen extract but not to HDM allergen was significantly reduced by blocking CD14. CONCLUSION: These results indicate that closely related innate immune cells from the myeloid lineage respond differentially to cat allergen extract and that the pattern-recognition receptor CD14 might be one of the mediators involved in the inflammatory responses to inhalant allergens.

Prediction of early graft occlusion in femoropopliteal and femorodistal reconstruction by measurement of volume flow with a transit time flowmeter and calculation of peripheral resistance.

A transit time flowmeter (Transonic TC101DTM, Transonic Inc., U.S.A.) was used for flow measurements and calculation of peripheral resistance in 48 primary femoropopliteal and femorodistal reconstructions. The results were correlated with primary graft occlusions during the first 90 postoperative days. There were 25 men and 23 women with a median age of 75 years (67-83). Eight were diabetic. Indications for surgery were rest pain (n = 23), ischaemic ulcer (n = 16), gangrene (n = 8) and popliteal aneurysm (n = 1). Measurements were made before reconstruction on the artery at the site of the distal anastomosis. After reconstruction flow measurements were made on the graft near the proximal and distal anastomoses together with a proximal graft pressure measurement. The peripheral resistance was calculated. Eleven grafts occluded and six patients died, four with patient grafts. Patients with graft occlusions had a significantly lower flow before (4 vs. 20 ml/min) and after (60 vs. 110 ml/min) reconstruction and a higher peripheral resistance, (1238 vs. 625 mPRU) than patients with patent grafts. The most significant differences were found in the femorodistal bypass grafts. The transit time flowmeter was easy to use. The flow before and after reconstruction as well as the peripheral resistance could be used for the prediction of graft function within 90 days of surgery.

Do residual arteriovenous fistulae after in situ saphenous vein bypass grafting influence patency?

PURPOSE: The purpose of this study was to evaluate the influence on patency of residual arteriovenous fistulae (AVF) after in situ saphenous vein bypass grafting. METHODS: Between January 1, 1994, and December 31, 1996, 98 in situ saphenous vein bypass grafting procedures were performed in 94 patients. Patency was evaluated with duplex scanning after operation and at 1, 3, 6, 9, and 12 months. RESULTS: The indications for operation were intermittent claudication in two patients and critical leg ischemia in 92 patients. Two above-knee and 48 below-knee femoropopliteal and 48 femorocrural in situ saphenous vein bypass grafting procedures were performed. The median follow-up period was 9 months (range, 1.5 to 12.5 months). There were no residual AVF in 45 veins (44%; group 1), but 110 residual AVF were found in 53 veins (56%; group 2). In group 2, 36 AVF in 18 veins were surgically or radiologically occluded mainly as a result of a flow velocity decrease distal to the AVF, but the remaining 74 AVF were treated conservatively. The 1-year cumulative primary patency rates were 68% in group 1 and 74% in group 2 (log-rank test, 0.47; degree of freedom = 1; P =.52). The 1-year cumulative assisted primary patency rates were 68% in group 1 and 81% in group 2 (log-rank test, 2.19; degree of freedom = 1; P =. 14). CONCLUSION: Residual AVF after in situ bypass grafting without influence on bypass graft hemodynamics do not compromise patency and thrombose spontaneously.

Patency of the plantar arch as a prognostic indicator in patients with critical leg ischaemia; a retrospective study.

OBJECTIVE: To find out if patency of the plantar arch on the preoperative angiogram was an accurate indicator of prognosis of vascular intervention, of leg salvage and of survival in patients with critical ischaemia of the leg. DESIGN: Retrospective study. SETTING: University Hospital. SUBJECTS: 302 patients who underwent femoral angiography for critical ischaemia of the leg in 1985-1986. INTERVENTIONS: Examination of aortofemoral angiograms and scoring of the radiological changes according to a suggested scoring system. MAIN OUTCOME MEASURES: Correlation of scores with outcome. RESULTS: Patients with patent plantar arches had a significantly higher cumulative patency after vascular intervention (logrank chi 2 4.2, p < 0.05), leg salvage (logrank chi 2 11.9, p < 0.01) and significantly longer survival (logrank chi 2 7.8 p < 0.01) than patients with partly or completely occluded plantar arches. CONCLUSION: It is important to see the plantar arch on the preoperative angiogram. The scoring system is valuable in predicting patency after vascular intervention, leg salvage and survival.

The uptake of platelets, fibrinogen and leucocytes in ePTFE vascular grafts in relation to blood flow--an experimental study in sheep.

The uptake of platelets, fibrinogen and leucocytes in relation to blood flow was studied in ePTFE arterial grafts inserted in both common carotid arteries of 10 adult sheep. Autologous platelets labelled with In-111, autologous leucocytes labelled with Tc-99m and homologous fibrinogen labelled with I-125 were used. The leucocyte uptake was studied in five of the animals. The uptake was measured with a gamma scintillation technique. The blood flow in the graft on one side was restricted to 25 ml/mm, and in the other graft the blood flow was unrestricted (median 170 ml/min). One out of 10 grafts in the reduced flow group occluded but none of the grafts in the unrestricted flow group. The mean thrombus weight was significantly higher in the reduced unrestricted flow (0.28 vs. 0.19 g). At the proximal anastomosis the uptake of platelets, fibrinogen and leucocytes was higher in the reduced than unrestricted flow. The differences were significantly higher for fibrinogen for the whole duration of the experiments and for platelets and leucocytes during the last 48 min. Distally the platelet and fibrinogen uptake were higher in the reduced than in unrestricted flow. The leucocyte uptake did not differ distally. The differences were significant for fibrinogen for the whole duration of the experiments and for platelets during the last 120 min. A comparison between the proximal and distal anastomosis showed a higher uptake distally.

Volume blood flow measurements with a transit time flowmeter: an in vivo and in vitro variability and validation study.

A transit time flowmeter, Transonic TC101 (Transonic Inc., USA) has been evaluated to study volume flow. Two flow probes, 4 and 6 mm, were used. The experiments were carried out in vivo on the carotid arteries (n = 16) in sheep and in vitro against a pre calibrated rotational pump. Exsanguination measurements, n = 32, were used for the calculation of the error of measurement in vivo. The error of measurement in vitro was calculated on 11 different flow rates from 0 to 150 ml min-1. The variability in vivo was evaluated using data from 10, 30 s measurement periods with a 30 s pause between measurements. The variability in vitro was evaluated at three flow rates (46, 78, and 113 ml min-1). Five 1-min measurements with a 1-min pause between measurements were made. The error of measurement in vivo was 12.05% and in vitro 5.50% (4 mm probe) and 14.90% (6 mm probe). In vivo the variability was between 1.1 and 4.4% and in vitro between 1.5 and 11.2%. The correlation coefficients between the flowmeter on the one hand and exsanguination and the rotational pump on the other were 0.99, 0.99 (4 mm probe) and 0.98 (6 mm probe). It is concluded that the flowmeter has a small variability and error of measurement both in vivo and in vitro.

Femoropopliteal-crural graft patency is improved by an intensive surveillance program: a prospective randomized study.

PURPOSE: The purpose of this study was to evaluate whether intensive surveillance compared with routine follow-up examinations improves femoropopliteal/crural graft patency. METHODS: After operation the patients were randomized to intensive (n = 79) or routine surveillance (n = 77). The groups were matched with regard to sex, diabetes, indication for surgical procedure, surgical procedure, and graft material. Intensive surveillance was clinical examination, ankle/brachial index measurements, and duplex scans 1, 3, 6, 9, 12, 15, 18, 21, 24, and 36 months after operation. Routine surveillance was clinical examination and ankle/brachial index measurements without duplex scanning 1, 12, 24, and 36 months after operation. Grafts with a decrease in ankle/brachial index of more than 0.15 compared with the initial postoperative ankle/brachial index or a duplex scan showing a graft or anastomotic stenosis of more than 50% underwent angiography and if necessary, a revision or repeat procedure. Occluded grafts were reopened with thrombectomy or thrombolysis or were replaced with a new graft. RESULTS: Assisted primary cumulative vein graft patency in the intensive group (n = 56) compared with that in the routine surveillance group (n = 50) after 3 years was 78% versus 53% (chi square analysis, 4.51; one degree of freedom; p < 0.05). Secondary patency was 82% versus 56% (chi square analysis, 5.62; one degree of freedom; p < 0.05). Assisted primary cumulative e-polytetrafluoroethylene and composite graft patency after 1 year in the intensive group (n = 23) compared with that of the routine surveillance group (n = 20) was 57% vs 50% (chi square analysis, 2.17; one degree of freedom; p > 0.1). Secondary patency was 67% vs 54% (chi square analysis, 1.85; one degree of freedom; p > 0.1). Revisions were made on 14 patent and 10 thrombosed grafts in the intensive group and on four patent and 15 thrombosed grafts in the routine surveillance group. All except eight were made during the first postoperative year. CONCLUSIONS: Intensive surveillance identified failing vein grafts leading to a significantly higher cumulative assisted primary and secondary patency compared with cumulative assisted primary and secondary patency after routine follow-up examination. The patency of e-polytetrafluoroethylene and composite grafts was not influenced by intensive surveillance.

Effect of dextran and enoxaparin on early ePTFE graft thrombogenicity in sheep.

OBJECTIVES: To evaluate the effect of low molecular weight heparin (LMWH), dextran 70 and their combination on platelet adhesion and fibrinogen uptake in ePTFE grafts in an experimental sheep model. DESIGN: Prospective open study. SETTING: Animal Laboratory of a University Hospital. MATERIALS: Early thrombogenicity of ePTFE grafts was studied after interposition in the two common carotid arteries of 40 adult sheep. The animals received one of four different treatment regimens in a double blind randomised way: enoxaparin and polygeline, saline and dextran 70, enoxaparin and dextran 70 or saline and polygeline (control). The substances were administered i.v. with a total dose of 73 antifactor-Xa U/kg for enoxaparin and 1.0 g/kg for dextran 70. Polygeline and saline were used as placebo substances in equivalent volumes. On one side (random allocation) the carotid blood flow was restricted to 25 ml/min, on the other side it was left unrestricted. CHIEF OUTCOME MEASURES: The following variables were studied: 1) fibrinogen uptake; 2) platelet uptake; 3) early graft patency; 4) blood flow in patient grafts; 5) visible presence of graft thrombus; 6) thrombus weight. MAIN RESULTS: The results verified the importance of adequate blood flow as only 30% of grafts with restricted blood flow in the control group were patent compared with 80% of those with unrestricted blood flow (p = 0.038). Dextran 70, enoxaparin and the combination of the two increased early graft patency (p < 0.05) and reduced thrombus weights (p < 0.05) in grafts with restricted blood flow. The relative number of grafts with thrombus free surface was increased in the unrestricted blood flow situation. CONCLUSIONS: Dextran 70 and enoxaparin appeared to be equally effective in decreasing fibrinogen and platelet uptake in the grafts. Their combination was not significantly more effective although there was a favourable trend.