Does Early Feeding Promote Development of Oral Tolerance?

The prevalence of food allergy has continued to rise over the last 10-15 years, with building concern over the underlying causes and the best strategies to reverse this. Although it is still not clear if infant feeding practices play any significant role in either the aetiology of this epidemic or in its prevention, these have nonetheless been core to many previous prevention strategies. Early 'allergen avoidance' strategies have not only failed, but have instead been increasingly associated with increased risk of allergic disease. Together with other observations in humans and animals, this suggests that earlier introduction of allergenic foods may be a more logical preventive strategy. Based on this, there are several randomised controlled trials world-wide assessing the merits of early introduction of complementary feeding and/or allergenic foods. Until the results of these studies are available it is difficult to provide definitive recommendations regarding the role of early feeding in the induction of oral tolerance and prevention of food allergy.     

Does Choice of Antidiabetes Therapy Influence Macrovascular Outcomes?

Despite a clear epidemiologic relationship between hemoglobin A_1c levels and the risk of cardiovascular (CV) disease in patients with type 2 diabetes mellitus (T2DM), prospective studies examining the benefit of intensive glucose lowering in reducing CV events have yielded conflicting results. Controversy over the choice of antidiabetic therapy for lowering macrovascular events has existed for nearly four decades, beginning with the potential risk of increased CV mortality with sulfonylurea use. Although sulfonylureas were subsequently felt to be safe, a more recent controversy was raised as to whether rosiglitazone use was associated with an increased risk of CV events. Additionally, early positive results for metformin in reducing macrovascular events have not been clearly substantiated. Because a typical patient with T2DM may live 20 to 40 years with the disease, long-term prevention of CV events is very important. An evidenced-based review of choice of antidiabetic therapy to reduce CV events in T2DM is discussed below.     

Endoscopy or surgery for malignant GI outlet obstruction?

BACKGROUND: The treatment of gastroduodenal outflow obstruction (GOO) caused by malignant diseases represents a significant challenge. Open surgical gastrojejunostomy (GJ) has been the treatment of choice, but it has high morbidity and mortality rates. More recently, endoscopic placement of self-expanding metallic stents (SEMS) has been proposed and the results of small, preliminary studies are encouraging. This study compared technical and clinical success, morbidity, mortality, and hospital stay in patients undergoing endoscopic and surgical treatment of GOO. METHODS: Medical records of 60 consecutive patients with GOO seen between April 1997 and November 2002 were retrospectively reviewed. Because of extremely short life expectancy, 13 patients were treated by insertion of a double-lumen nasogastric-jejunal tube. The remaining 47 patients (28 men, 19 women; mean age 73.5 years, range 48-92 years) with unresectable pancreatic (33), gastric (7), metastatic lymph nodal (4), papillary (2), and biliary (1) tumors were treated by placement of a SEMS (24) or open surgical GJ (23). RESULTS: The technical success rates were similar, but clinical success was lower in the GJ group (92% vs. 56%, p = 0.0067). The SEMS group had a shorter length of hospital stay (3.0 [1.4] days vs. 24.1 [10.3], p < 0.001). Thirty-day mortality was 30% in the GJ group, and 0% in the SEMS group ( p = 0.004). Morbidity was higher in the GJ compared with the SEMS group (61% vs. 17%, p = 0.0021). Mean survival was longer in the SEMS group (96.1 [9.6] days vs. 70.2 [36.2] days, p = 0.0165 for a single test of hypothesis; Bonferroni correction for a multiple testing removes this significance), consequently, out-of-hospital survival was longer for the SEMS group (93.2 [9.3] days vs. 46.0 [31.5] days, p < 0.001). None of the endoscopic procedures required the assistance of an anesthesiologist or the use of an operating room. CONCLUSIONS: The results of this retrospective study suggest that SEMS insertion is better than surgical GJ for palliation of patients with GOO in terms of clinical success, morbidity, and mortality. Technical success rates were similar. SEMS placement should be proposed as the first-line treatment for relief of GOO. However, a randomized, comparative, prospective study of SEMS vs. laparoscopic GJ is needed.     

The SHAPE Guideline: Ahead of Its Time or Just in Time?

In 2006, a grass roots movement called SHAPE (Screening for Heart Attack Prevention and Education) published a novel practice guideline for cardiovascular screening in the asymptomatic at-risk population. It suggested the use of noninvasive tests for subclinical atherosclerosis in cardiovascular risk assessment to target intensified preventive care to those at highest risk. The SHAPE guideline received much attention but not as much support from the “official” medical societies. However, subsequent studies published since 2006 have now provided strong supportive evidence for the strategy spearheaded by the SHAPE guideline. Indeed, the latest guidelines issued jointly by the American Heart Association and the American College of Cardiology have elevated recommendation levels for noninvasive imaging of subclinical atherosclerosis. This change is widely viewed as a significant step toward the SHAPE guidelines. The background for SHAPE and the evidence behind the recommendation to use coronary artery calcium score measured by computed tomography, carotid intima-media thickness and plaque measured by ultrasound, and ankle-brachial index in cardiovascular risk assessment is reviewed in this article.     

MARS—Does It Stand the Test of Time?

Artificial liver support systems have been tested for decades in the management of liver failure. Generally, after some promising results published as case series, the device either disappears or fails to show significant benefit in controlled trials. Recently, the molecular absorbent recycling systems (MARS) or extracorporeal albumin dialysis (ECAD) technique appears to have broken this trend. Responding to the title one could summarize by saying this technique so far has stood the test of time. Data in support of its use in acute liver failure (ALF) is still scant and difficult to assess. However, in a well known but not very well defined entity of acute on chronic liver failure (AOCLF) the ECAD technique has been shown to improve survival compared to a similar randomized control group receiving standard supportive therapy. This well tolerated liver support system has real potential for widespread application if further well designed multicenter clinical trials continue to support its effectiveness. Its future lies probably in the management of the moribund hospitalized patient on the transplant list awaiting a donor liver.     

Does Sulfation of Gastrin Influence Gastric Acid Secretion in Man?

To assess the physiologic significance of tyrosine o-sulfation of gastrin in humans, the gastric acid stimulatory potencies of sulfated and non-sulfated human gastrin-17 were compared in six normal young subjects. Sulfated and non-sulfated forms of synthetic human gastrin-17 were infused intravenously in doses from 12.7 to 478 pmol/ kg/h. Similar acid secretory responses were observed. The calculated maximal acid response for sulfated gastrin-17 was 35.7 ± 4.3mmol/h, and that for non-sulfated gastrin-17 was 39.8 ± 7.5 mmol/h (mean ± SEM, NS). The 50% effective dose of sulfated gastrin-17 was 22.2 ± 6.7pmol/kg/h, whereas it was 29.3 ± 5.8pmol/kg/h for non-sulfated gastrin-17 (NS). Finally, the 50% effective concentration of gastrin in serum was 34.7 ± 5.0 pmol sulfated gastrin-17/1 and 42.5 ± 11.8 pmol non-sulfated gastrin-17/1 (NS). The results show that tyrosine o-sulfation is without significant influence on the gastric acid secretory potency of gastrin in man. Moreover, the results also suggest that sulfated and non-sulfated gastrin-17 in man have similar rates of metabolism.     

Does Backgrounds Color Influence the Appearance of Gingiva-Colored Resin-Based Composites?

Dental materials are mainly tested in vitro, so laboratory conditions must reproduce the oral environment to ensure the validity of their results. This study aimed to evaluate the influence of backgrounds on the color of gingiva-colored resin-based composites (GCRBC). Three discs of each of 20 shades of GCRBCs and each thickness (1 and 2 mm) were prepared. Diffuse reflectance was measured on-air and over three natural teeth (0M3/B1, 3M3/B3, and 5M3/B4 shades of Vita 3D Master/Vita Classical guides, respectively) using a calibrated spectroradiometer, CIE D65 illuminant and the CIE 45°/0° geometry. CIEDE2000 color difference formula and its 50:50% perceptibility and acceptability thresholds have been used to calculate and interpret the results. It can be stated that the background influences the color of all GCRBCs tested, although the effect is more pronounced for 1 mm thick samples. L*, a* and b* coordinates values of GCRBCs on air were significantly different from those obtained on natural teeth backgrounds, and the total color differences were greater than the acceptability thresholds. Since GCRBCs are placed on a dental substrate in clinical conditions, it is not advisable to perform color measurements of GCRBCs on-air because of the high color differences found. This recommendation is especially relevant for thin specimens.     

Asymptomatic Carotid Stenosis: Immediate Revascularization or Watchful Waiting?

Based on several randomized clinical trials, carotid revascularization has been shown to reduce future stroke risk among individuals with severe asymptomatic carotid stenosis. However, a well-recognized problem with such prophylactic intervention is the risk of periprocedural stroke, death, or myocardial infarction. If actual stroke risk with asymptomatic carotid stenosis can be reduced significantly by aggressive medical management, carotid revascularization may yield marginal benefit or even cause harm especially in those with limited life expectancy. Based on recent observational data, it is becoming apparent that the stroke risk in this population has been declining with better medical management alone. This has prompted a few to avoid carotid revascularization for asymptomatic carotid stenosis altogether. Others feel such conclusions cannot be made with observational data alone. In the midst of this controversy, it is important that clinicians perform carotid revascularization on a case by case basis while ensuring optimal medical management in all patients. An algorithmic approach to decision making based on available evidence will enable clinicians to personalize patient management with efficiency.