Human antibody against C domain of tenascin-C visualizes murine atherosclerotic plaques ex vivo.

Targeting proteins that are overexpressed in atherosclerotic plaques may open novel diagnostic applications. The C domain of tenascin-C is absent from normal adult tissues but can be inserted during tumor progression or tissue repair into the molecule by alternative splicing. We tested the ability of the human antibody G11, specific to this antigen, to reveal murine atherosclerotic plaques ex vivo. The antibody directed against the extra domain B of fibronectin (L19) was used as a reference. METHODS: We intravenously injected (125)I-labeled G11 or L19 antibodies into apolipoprotein E-deficient (ApoE(-/-)) mice and harvested the aortae 4 or 24 h later. En face analyses of distal aortae and longitudinal sections of the aortic arch were performed to compare antibody uptake using autoradiography with plaque staining using oil red O. Plaque macrophages were detected by immunohistochemistry (anti-CD68 staining). Biodistribution of injected antibodies was investigated in aortae and blood at 4 and 24 h. RESULTS: En face analyses revealed a significant correlation between radiolabeled G11 and fat-stained areas, increasing from 4 to 24 h, with a correlation coefficient of 0.92 (P < 0.0001) and an average signal-to-noise ratio of 104:1 at 24 h. Plaque imaging using L19 showed similar results (r = 0.86; P < 0.0001; signal-to-noise ratio, 72:1 at 24 h). Uptake of radiolabeled antibodies in histologic sections colocalized with fat staining and activated macrophages in aortic plaques. Biodistribution analyses confirmed specific accumulation in aortic plaques as well as rapid blood pool clearance of the antibodies 24 h after injection. Immunofluorescence analyses revealed increased expression of tenascin and fibronectin isoforms in macrophage-rich plaques. CONCLUSION: The antibody G11, specific to the C domain of tenascin-C, visualizes murine atherosclerotic plaques ex vivo. In conjunction with the increased expression of the C domain of tenascin-C in macrophage-rich plaques, the colocalization of G11 uptake with activated macrophages, and the favorable target-to-blood ratio at 24 h, this antibody may be useful for molecular imaging of advanced atherosclerotic plaques in the intact organism.     

Preoperative pulmonary rehabilitation in patients undergoing lung resection for non-small cell lung cancer.

BACKGROUND: The impact of short-term preoperative pulmonary rehabilitation on exercise capacity of patients with chronic obstructive pulmonary disease undergoing lobectomy for non-small cell lung cancer is evaluated. METHODS: A prospective observational study was designed. Inclusion criteria consisted of an indication to lung resection because of a clinical stage I or II non-small cell lung cancer and a chronic obstructive disease on preoperative pulmonary function test. In such conditions, maximal oxygen consumption by a cardio-pulmonary exercise test was evaluated; when this resulted as being < or =15 ml/kg/min a pulmonary rehabilitation programme lasting 4 weeks was considered. Twelve patients fulfilled inclusion criteria, completed the preoperative rehabilitation programme and underwent a new functional evaluation prior to surgery. The postoperative record of these patients was collected. RESULTS: On completion of pulmonary rehabilitation, the resting pulmonary function test and diffuse lung capacity of patients was unchanged, whereas the exercise performance was found to have significantly improved; the mean increase in maximal oxygen consumption proved to be at 2.8 ml/kg/min (p<0.01). Eleven patients underwent lobectomy; no postoperative mortality was noted and mean hospital stay was 17 days. Postoperative pulmonary complication was recorded in 8 patients. CONCLUSIONS: Short-term preoperative pulmonary rehabilitation could improve the exercise capacity of patients with chronic obstructive pulmonary disease who are candidates for lung resection for non-small cell lung cancer.     

A-alpha-nerve-fiber: number of neurotubules in the stem fibre and in the terminal branches

Summary Cross sections of A--motor stem fibres of the rat accessory nerve and of one of its branches, the N. musculi sternomastoidei were compared with cross sections of terminal branches of the same nerve, with respect to the axonal cross sectional areas and the number of neurotubules. The absolute number of neurotubules in a stem fibre was found to be on average five times that of one of its terminal branches, corresponding to the ratio of their axonal cross-sectional areas. Thus no significant differences could be found in the tubular density of large stem fibres and of small final branches. Taking into account that in the course of the terminal ramification the total axonal cross-sectional area increases (Zenker and Hohberg, 1973), the combined total of the numbers of neurotubules in all terminal branches of a single A--fibre of the nerve innervating the sternomastoid muscle surpasses the amount of tubules in the stem fibre on average about 11 times. These findings are incompatible with the idea of a constant number of neurotubules within a given axon and its branches. In accordance with recent biochemical studies of microtubular protein, our results indicate that neurotubules may be formed in axon branches far from the perikaryon.     

Lung dendritic cells are primed by inhaled particulate antigens, and retain MHC class II/antigenic peptide complexes in hilar lymph nodes for a prolonged period of time

Intratracheal (IT) administration of heat-killed Listeria monocytogenes (HKL) results in an influx of macrophage and dendritic cell (DC) precursors into the lung interstitium. Low-density, FcR+, interstitial lung cells isolated from rats instilled 24 hr before with HKL or vehicle alone, were > 90% Mar1+. After culturing with granulocyte-macrophage colony-stimulating factor (GM-CSF) for 3 days, up to 24% of the loosely adherent cells were DC that stimulated allogeneic T-cell proliferation in an mixed lymphocyte reaction (MLR) assay. After only an overnight incubation with GM-CSF, however, the capacity of interstitial Mar1+ cells to stimulate HKL immune T-cell proliferation without exogenous antigen was low. By contrast, when DC were isolated as major histocompatibility complex (MHC) class II+ cells from rat lungs at 1, 3, 7 and 14 days after HKL instillation and cultured overnight with GM-CSF, their antigen presentation capacity without added exogenous antigen was robust, but declined over the 2-week period. Interestingly, hilar lymph node DC maintained their HKL antigen-presenting capacity for up to 2 weeks after instillation of HKL. Following IT administration of PKH-26 labelled HKL, fluorescent or immunolabelled organisms were detected in OX62+ DC in airway epithelium, lung interstitium and hilar lymph nodes in situ and in MHC class II+ DC isolated from these sites. We conclude that newly immigrated Mar1+ lung DC precursors, while efficient in endocytosing particulate antigens, are incapable of eliciting a significant proliferative response from HKL-sensitized T cells. By contrast, MHC class II+ DC isolated from lungs and incubated overnight with GM-CSF induce vigorous antigen-specific T-cell proliferation. Antigen-loaded lung DC in hilar lymph nodes maintain their antigen presentation capacity for up to 2 weeks.     

Disability-Adjusted Life Years Averted Versus Quality-Adjusted Life Years Gained: A Model Analysis for Breast Cancer Screening

ObjectivesTo quantify the impact of mammography-based screening on the quality of life, disability-adjusted life years (DALYs) averted or quality-adjusted life years (QALYs) gained can be used. We aimed to assess whether the use of DALYs averted or QALYs gained will lead to different cost-effective screening strategies.MethodsUsing the microsimulation model MISCAN, we simulated different breast cancer screening strategies varying in starting age (starting at 45, 47, and 50 years), stopping age (stopping at 69, 72, and 74 years), and frequency (annual [A], biennial [B], combination of both [A + B], and triennial [T]). In total, we defined 24 different breast cancer screening strategies, including no screening as a reference strategy. We calculated incremental cost-effectiveness ratios (ICERs) and compared which strategies were on the efficiency frontiers for DALYs and QALYs.ResultsBreast cancer screening averted between 46.00 and 105.58 DALYs and gained between 28.69 and 64.50 QALYs per 1000 women. For DALYs there were 5 strategies on the efficiency frontier (T50-69, T50-74, T45-74, B45-74, and A45-74). The same strategies plus one (B45-72) were on the efficiency frontier for QALYs.ConclusionsUsing DALYs averted instead of QALYs gained to assess the effects on quality of life from breast cancer screening in the Dutch population yields differences in ICERs, but almost the same strategies were on the efficiency frontiers. Whether the choice in outcome measure leads to a difference in optimal policy depends on the cost-effectiveness threshold.     

Bilateral cystoid macular edema following successful treatment of AIDS-associated CMV retinitis

Background: Cystoid macular edema (CME) in AIDS patients with inactive cytomegalovirus (CMV) retinitis is an uncommon but potentially sight-threatening complication. The pathogenesis of CME in these patients is unclear. This study tries to identify possible risk factors by analyzing the charts of five patients. Methods: Ten eyes of 5 patients that finally developed CME were followed for an average of 18 months. The initial retinal lesions, their response to antiviral treatment, the development of CME, and the patients' immune status were prospectively monitored. Results: CMV retinitis was diagnosed at a median CD4+ count of 3 cells/mm³ (range 0–11). All eyes responded to the initial systemic anti-viral treatment. At the onset of CME, CMV retinitis was controlled by antiviral maintenance therapy in all patients [ganciclovir (n = 2), cidofovir (n = 2), foscarnet (n = 1)]. The median time between diagnosis of CMV retinitis and onset of CME was 11.5 months (range 5–24). Development of CME was associated with significant visual loss: acuity ranged from 0.05 to 0.7 when CME was first noticed, compared to 0.8–1.25 at diagnosis of CMV retinitis. Duration of inflammation, size or zone of retinal necrosis did not favor the development of CME, neither did the antiviral therapy. A weak correlation of CME development and immune status (expressed as increase of CD4+ cells) was found. Due to systemic corticosteroids CME resolved. Conclusions: CME is a new visual threat to AIDS-patients with CMV retinitis whose immune status improved under the latest combined antiretroviral therapy. Therapy with oral corticosteroids may positively influence this condition.      

Proceedings of the Symposium ‘Angiotensin AT1 Receptors: From Molecular Physiology to Therapeutics’: REGULATION OF RENAL TUBULAR SODIUM TRANSPORT BY ANGIOTENSIN II AND ATRIAL NATRIURETIC FACTOR

• 1 The effects of angiotensin II (AngII) on water and electrolyte transport are biphasic and dose-dependent, such that low concentrations (10^?12 to 10^?9 mol/L) stimulate reabsorption and high concentrations (10^?7 to 10^?6 mol/L) inhibit reabsorption. Similar dose-response relationships have been obtained for luminal and peritubular addition of AngII.
• 2 The cellular responses to AngII are mediated via AT₁ receptors coupled via G-regulatory proteins to several possible signal transduction pathways. These include the inhibition of adenylyl cyclase, activation of phospholipases A₂, C or D and Ca²⁺ release in response to inositol-1,4,5,-triphosphate or following Ca²⁺ channel opening induced by the arachidonic acid metabolite 5,6,-epoxy-eicosatrienoic acid. In the brush border membrane, transduction of the AngII signal involves phospholipase A₂, but does not require second messengers.
• 3 Angiotensin II affects transepithelial sodium transport by modulation of Na⁺/H⁺ exchange at the luminal membrane and Na⁺/HCO₃ cotransport, Na⁺/K⁺-ATPase activity and K⁺ conductance at the basolateral membrane.
• 4 Atrial natriuretic factor (ANF) does not appear to affect proximal tubular sodium transport directly, but acts via specific receptors on the basolateral and brush border membranes to raise intracellular cGMP levels and inhibit AngII-stimulated transport.
• 5 It is concluded that there is a receptor-mediated action of ANF on proximal tubule reabsorption acting via elevation of cGMP to inhibit AngII-stimulated sodium transport. This effect is exerted by peptides delivered at both luminal and peritubular sides of the epithelium and provides a basis for the modulation by ANF of proximal glomerulotubular balance. The evidence reviewed supports the concept that in the proximal tubule, AngII and ANF act antagonistically in their roles as regulators of extracellular fluid volume.

     

Glycemic Control after Sleeve Gastrectomy and Roux-En-Y Gastric Bypass in Obese Subjects with Type 2 Diabetes Mellitus

Background

Roux-en-Y gastric bypass (LRYGB) has weight-independent effects on glycemia in obese type 2 diabetic patients, whereas sleeve gastrectomy (LSG) is less well characterized. This study aims to compare early weight-independent and later weight-dependent glycemic effects of LRYGB and LSG.

Methods

Eighteen LRYGB and 15 LSG patients were included in the study. Glucose, insulin, GLP-1, and GIP levels were monitored during a modified 30 g oral glucose tolerance test before surgery and 2 days, 3 weeks, and 12 months after surgery. Patients self-monitored glucose levels 2 weeks before and after surgery.

Results

Postoperative fasting blood glucose decreased similarly in both groups (LRYGB vs. SG; baseline—8.1?±?0.6 vs. 8.2?±?0.4 mmol/l, 2 days—7.8?±?0.5 vs. 7.4?±?0.3 mmol/l, 3 weeks—6.6?±?0.4 vs. 6.6?±?0.3 mmol/l, respectively, P <?0.01 vs. baseline for both groups; 12 months—6.6?±?0.4 vs. 5.9?±?0.4, respectively, P <?0.05 for LRYGB and P <?0.001 for LSG vs. baseline, P =?ns between the groups at all times). LSG, but not LRYGB, showed increased peak insulin levels 2 days postoperatively (mean?±?SEM; LSG +?58?±?14%, P <?0.01; LRYGB ??8?±?17%, P =?ns). GLP-1 levels increased similarly at 2 days, but were higher in LRYGB at 3 weeks (AUC; 7525?±?1258 vs. 4779?±?712 pmol?×?min, respectively, P <?0.05). GIP levels did not differ. Body mass index (BMI) decreased more after LRYGB than LSG (??10.1?±?0.9 vs. ??7.9?±?0.5 kg/m², respectively, P <?0.05).

Conclusion

LRYGB and LSG show very similar effects on glycemic control, despite lower GLP-1 levels and inferior BMI decrease after LSG.