Inhibitory Fc Gamma Receptors: From Gene to Disease

Multiple lines of evidence have revealed a key role for inhibitory Fc gamma receptors class IIb (FcgammaRIIb) as negative modulators of innate and adaptive immune responses. Acquired and genetic factors regulate the expression of FcgammaRIIb receptors and modify their inhibitory potential. Recent advances have highlighted the importance of FcgammaRIIb receptors in influencing the development of cancer and autoimmunity. The association of increased FcgammaRIIb expression with tumor development is believed to operate at effector cell level resulting in inhibition of antitumor cytotoxicity. In autoimmune diseases, FcgammaRIIb receptors play a major role in controlling the amplitude of antibody- and immune complex-mediated reactions. Generally, FcgammaRIIb deficiency is associated with increased susceptibility and severity to organ-specific and systemic autoimmunity. This article discusses the proposed mechanisms for FcgammaRIIb deregulation associated with malignant and autoimmune pathology in animal models and human diseases.     

An unusual origin of the celiac trunk and the superior mesenteric artery in the thorax

The authors report a case of a 44‐year‐old male found to have unusual origins of the celiac trunk (CT) and superior mesernteric artrery (SMA) as revealed by routine multidetector computed tomograph (MDCT) angiography. The CT and SMA originate from the thoracic aorta (TA) 21 mm and 9 mm above the aortic hiatus, respectively. The median arcuate ligament (MAL) is located at the level of the L1–L2 intervertebral disc. The course of the CT descends in the thoracic cavity making a 14° acute downward angle in front of the TA; below the level of the MAL, the CT descends, making an angle of 47°. The course of the SMA descends at both the thoracic and abdominal level making an angle of 17°, and having an aortomesenteric distance of 9 mm at the level of the third part of the duodenum. In the present case, the supradiaphragmatic origin of the CT and the SMA was determined by their incomplete caudal descent, associated with a pronounced apparent descent of the diaphragm. A thoracic origin of the CT and SMA and the acute downward aortomesenteric angle (17°) associated with a reduced aortomesenteric distance at the level of the third part of the duodenum (9 mm), although no clinical signs are present, may predispose the patient to develop simultaneously a triple syndrome: the compression of CT by MAL (celiac axis compression syndrome), the compression of SMA by MAL (superior mesenteric artery compression syndrome), and the compression of the duodenum by the SMA (superior mesenteric artery syndrome). Clin. Anat. 26:975–979, 2013. © 2013 Wiley Periodicals, Inc.     

Complications hépatobiliaires associées à l’insuffisance intestinale chez l’adulte et l’enfant

The treatment of chronic intestinal failure, of which the main cause is the short bowel syndrome, is based on parenteral nutrition. Intestinal failure-associated liver disease, which may worsen toward cirrhosis, is the most threatening intestinal failure-associated complication. Risk factors for intestinal failure-associated liver disease are related to parenteral nutrition modalities and to the underlying disease. Bowel rest and short bowel syndrome are risk factors for biliary lithiasis. Steatosis is mainly secondary to nutritional factors (excess of glucose and/or lipids, continuous parenteral nutrition). The main risk factors of cholestasis are intestinal resection, intestinal bacterial overgrowth, excess of long-chain polyunsaturated ω6 fatty acids and phytosterols from some lipid emulsions. Liver chronic inflammation, another risk factor for intestinal failure-associated liver disease, is related to recurrent infections, bacterial or toxinic translocation, high intake of long-chain polyunsaturated ω6 fatty acids as precursors of inflammatory mediators. Fibrosis, secondary to any lesions, could progress toward cirrhosis with portal hypertension and liver failure. In such condition, the only life-saving treatment is a combined liver-intestinal transplantation. The prevention is based on the identification of patients with high risk of complicated liver disease, and on the optimal management of both underlying disease and parenteral nutrition. Routine surveillance is based on biological markers of variable sensitivity and specificity, and ultrasonography. Liver biopsy is required to diagnose fibrosis, especially prior to decide for an isolated intestinal transplantation or combined intestine-liver transplantation.     

Challenges of acute phase neuroimaging in VA-ECMO,pitfalls and alternative imaging options

Large vessel occlusion in patients on ECMO is challenging to appreciate clinically secondary to sedation or induced paralysis, thus placing more emphasis on neurovascular imaging. However, emergent CTA and CTP are both inaccurate and unreliable in ECMO patients due to altered circuitry and interference with normal physiologic hemodynamics. In this review, the utility of DSA is discussed in evaluating the altered hemodynamics of VA-ECMO circuits and patency of major vasculature. In addition, the potential use of TCD in ECMO patients is discussed.     

Common Limb Length Does Not Influence Weight Loss After Standard Laparoscopic Roux-En-Y Gastric Bypass

Background

Although Roux-en-Y gastric bypass (RYGBP) has proven its reliability over time in terms of weight loss and resolution of comorbidities, there continues to be a significant controversy in terms of used limb lengths. In the classical RYGBP, most surgeons have reported an alimentary limb length (ALL) of 100 to 150 cm and a bilio-pancreatic limb length (BPLL) of 50 to 75 cm. On the other hand, the common limb length (CLL) remains unknown in all the patients. As it is theoretically related to the level of malabsorption, CLL could influence weight loss after RYGBP.

Materials and Methods

We performed a laparoscopic RYGBP in 90 patients with a mean preoperative body mass index (BMI) of 44.8. ALL and BPLL were respectively fixed at 150 and 75 cm. A systematic intraoperative measurement of CLL was performed.

Results

As expected, we found a great variation of the jejuno-ileal length and also of the CLL. We created three subgroups of patients: one with the entire population, one excluding the super-obese patients (BMI?>?50) and the third one excluding the revisions. There was no statistically significant correlation between CLL and excess BMI loss (EBMIL) at 1, 3, 6 and 12 months of follow-up in each group. We also found a linear correlation between the jejuno-ileal length and the height of individuals.

Conclusion

With a fixed 150-cm ALL and a 75-cm BPLL, there is no evidence that the anatomical variations of CLL could influence weight loss after classical RYGBP.

     

Wettability and Surface Roughness Analysis of Laser Surface Texturing of AISI 430 Stainless Steel

Due to its wide applicability in industry, devising microstructures on the surface of materials can be easily implemented and automated in technological processes. Laser Surface Texturing (LST) is applied to modify the chemical composition, morphology, and roughness of surfaces (wettability), cleaning (remove contaminants), reducing internal stresses of metals (hardening, tempering), surface energy (polymers, metals), increasing the adhesion (hybrid joining, bioengineering) and decreasing the growth of pathogenic bacteria (bioengineering). This paper is a continuation and extension of our previous studies in laser-assisted texturing of surfaces. Three different patterns (crater array-type C, two ellipses at 90° overlapping with its mirror-type B and 3 concentric octagons-type A) were applied with a nanosecond pulsed laser (active medium Nd: Fiber Diode-pumped) on the surface of a ferritic stainless steel (AISI 430). Micro texturing the surface of a material can modify its wettability behavior. A hydrophobic surface (contact angle greater than 90°) was obtained with different variations depending on the parameters. The analysis performed in this research (surface roughness, wettability) is critical for assessing the surface functionality, characteristics and properties of the stainless steel surface after the LST process. The values of the surface roughness and the contact angle are directly proportional to the number of repetitions and inversely proportional to the speed. Recommendations for the use of different texturing pattern designs are also made.