Adenoviras-mediated expression of human CD59 on xenogeneic endothelial cells: Protection against human complement-mediated lysis and induction of cellular activation by adenoviral transduction

Abstract: The expression of human regulators of complement activation in endothelium of a transplanted organ is an approach to overcoming the complement (C)-mediated rejection of a xenograft. We designed a replication-deficient adenovirus (Ad) containing the human CD59 cDNA (AdCD59) in order to induce expression of human CD59 on xenogeneic endothelial cells (EC) and confer protection against human C-mediated lysis. In vitro transduction of rat EC with AdCD59 led to consistent levels of CD59 expression in all cells and significantly reduced EC lysis induced by human xenogeneic natural antibodies (XNA) binding and C activation. In addition, we analyzed whether Ad transduction had modified the phenotype of EC and the xenogeneic recognition of EC by human serum. For this, we first demonstrated that transduction of rat EC with AdCD59 or an Ad carrying the lacZ gene (AdlacZ) markedly enhanced the expression of some cell-membrane markers of EC activation, including class I MHC antigens and rat CD59, to levels comparable to those obtained with TNFα Up-regulation of class I MHC antigens was observed for both mRNA and protein expression. In contrast, AdCD59-mediated gene transfer slightly increase intercellular adhesion molecule-1 (ICAM-1) and did not modify the expression of Crry, a rat complement regulatory molecule. Second, we showed that these phenotypic modifications of EC did not affect the expression of the Galαl-3Gal epitope and the binding of human XNA. In addition, neither AdlacZ-mediated transduction, nor TNFα treatment, modified the sensitivity of xenogeneic EC to human serum-mediated lysis. In conclusion, this study demonstrated that transduction of human CD59 with an adenoviral vector conferred resistance to xenogeneic cultured EC against human C-mediated lysis but is associated with cellular activation of transduced EC. This finding may have important implications for the in vivo protocols and strategies intended to generate safer Ad vectors.     

Helicobacter species and liver diseases: association or causation?

The discovery of Helicobacter hepaticus as a causal agent of hepatitis and hepatocarcinoma in mice has stimulated interest in looking for Helicobacter spp in human liver samples. These bacteria could be a risk factor for the progression of liver disease to cirrhosis and hepatocellular carcinoma, especially among patients chronically infected with hepatitis C virus. We reviewed the studies done on this topic, and, with the exception of one, all studies reported an association between the presence of Helicobacter spp and liver disease. However, these data are weakened by the fact that Helicobacter spp DNA was detected but no bacteria could be grown, and by the difficulties in identifying the Helicobacter spp involved. More studies are therefore needed to confirm whether a causal association exits between the presence of Helicobacter spp in the liver and the development of cirrhosis and hepatocellular carcinoma.     

Differential responses of olfactory neurons to axotomy at embryonic and postnatal stages.

In the nervous system, apoptosis is a major process during embryonic and postnatal stages. In chick, experimental cell death can be obtained by axotomy. We have compared the responses of olfactory neurons to axotomy at embryonic stage E17 and postnatal stages.Forty-three chicken embryos and 32 young chickens less than 3 weeks old were used. We combined optic microscopy, electronic microscopy, terminal (TdT)-mediated dUTP-nick end labeling (TUNEL) method and gel electrophoresis of genomic DNA to analyze cell death. Cells in synthetic phase were labeled by bromodeoxyuridine injected i.p. and detected by immunohistochemistry. Apoptotic index and 5-bromo-2'-deoxyuridine (BrdU) labeling index were calculated for each stage. The Wilcoxon test was used for statistical analysis. A P value <0.05 was considered significant.Within 3 days following axotomy in E17 chicken embryos, there was no significant increase of apoptosis on the lesion side analyzed 3, 6, 12, 18, 24, 48 or 56 h later. A slight increase of bromodeoxyuridine incorporation appeared at 3 h, was weakly significant at 24 h (P=0.045) and the return to basal rate took place at 48 h. In postnatal stages, an apoptotic wave appeared 12 h after axotomy, reached a maximum at 24 h, and then decreased between 48 h and 72 h. A significant elevation of bromodeoxyuridine incorporation occurred on 48 h with a 24 h delay after the peak of apoptotic death.This differential response to axotomy in embryos and postnatal chickens might be due to a less complete maturation and higher plasticity of embryonic olfactory neurons corresponding to different requirement for survival and differentiation factors. Thus the embryonic or immature neurons would depend more on local epithelial environment and mature or postnatal neurons would require target-derived survival factors and die from apoptosis after their shortage resulting from axotomy.     

Lymph node dissection in non-medullary differentiated thyroid carcinoma

Papillary and follicular thyroid carcinomas are the most common form of endocrine carcinomas. Lymph node involvement seems to be a low risk factor for death, but it increases the risk for loco-regional recurrences and distant metastasis. The limits and the key points of the cervical lymph node dissection are described. The sentinel lymph node is used to rarely, so it could limit the lymph dissection. Node-picking has to be avoided. Central lymph node resection is recommended for high-risk patients, as male, patients more than 45 or less than 21 years old, papillary carcinomas greater than 1 cm or follicular carcinoma more than 2 cm in diameter. Lateral lymph node resection is performed when the lymph nodes of the central compartment are involved, more than 3 cm in diameter, and bulked. Prophylactic lymphadenectomy is useless. When thyroid carcinoma is known postoperatively, re-operation depends of the cervical mass and of the results of the radioactive iodine treatment.     

Sporadic primary hyperparathyroidism

Primary hyperparathyroidism (HPT1) is a common endocrine disorder, which is asymptomatic in 80% of cases. The diagnosis is ordinarily easily made, based on an inappropriately elevated parathormone level (PTH) in the face of hypercalcemia. In 85% of cases, HPT1 is due to hormone secretion from a single parathyroid gland (uniglandular disease) and the remaining patients have multiglandular disease. The best localization study is MIBI scintigraphy (methoxy isobutyl isonitrile) coupled with the results of a neck ultrasound exam (sensitivity >95%). Other investigations are reserved for patients with persistent or recurrent HPT1 post-surgery. Surgery is the only cure. The surgical approach may include a bilateral cervical exploration, a unilateral approach under local anesthesia, or focused minimally invasive (video-assisted or totally endoscopic) approaches. A decrease in PTH level measured intraoperatively of greater than 50% is predictive of cure in more than 97% of cases. Surgery is recommended even for moderate HPT1 and for very elderly patients because improvement in both the quality of life and bone density have been proven in these situations. The role of medical treatment is limited. Persistent or recurrent HPT1 requires a meticulous diagnostic approach and management in surgical centers with expertise. Persistent elevation of PTH postoperatively without hypercalcemia does not mandate further exploration. The prognosis of normocalcemic patients with elevated postoperative PTH levels remains uncertain.     

Gastrointestinal carcinoid tumors: a multi-technique diagnostic approach

Carcinoid tumors account for less than 1% of all malignancies. The majority arise in the gastrointestinal system (GI carcinoids). The diagnosis of GI carcinoids is often made late, the protean symptoms are easy to overlook. Diagnosis, prognosis and treatment options are based on biochemical markers and imaging investigations. A high concentration of urinary 5-HIAA or an elevated serotonin level in plasma help to establish the diagnosis of GI carcinoid. Plasma chromogranin A has poor specificity (68%); its level depends on disease involvement and therapeutic response. Octreoscan is the best imaging technique to detect GI carcinoids, but CT scan and MRI are superior for the detection of metastasis. 18F-DOPA or 11C-5-HTP/PET, imaging fusion as of octreoscan or PET scan with CT or MRI, improve the results of metabolic imaging. Coronal contrast-enhanced CT or MRI angiogram can evaluate mesenteric vessel spread before surgery. Upper endoscopy or colonoscopy, can be performed to detect foregut carcinoid in MEN, or hindgut carcinoid. Echoendoscopy visualizes abdominal wall and local node involvement. Enteroscopy and capsule endoscopy localize 66% of midgut carcinoids. Although there have been considerable advances in diagnostic modalities, the diagnosis of carcinoid tumors is still, all too often, late.     

Primary vertebral osteosarcoma: Five cases

Primary vertebral osteosarcoma is a rare type of osteosarcoma, differing from the appendicular forms by an incidence peak occurring at a higher age and a poorer prognosis, due to the difficulties of the surgical treatment. We present five cases of histologically proven primary vertebral osteosarcomas followed in our institution between 2004 and 2012. They allow to illustrate some essential radiologic features, useful to evoke this rare entity.     

Efficiency of [<Superscript>18</Superscript>F]FDG PET in characterising renal cancer and detecting distant metastases: a comparison with CT

The purpose of this study was to assess the efficiency of fluorine-18 fluoro-2-deoxyglucose (FDG) positron emission tomography (PET) in the characterisation and primary staging of suspicious renal masses, in comparison with computed tomography, the current standard imaging modality. Fifty-three FDG PET studies were performed within the framework of a prospective study: 35 for both characterisation and staging of a suspicious mass, and 18 for staging early after surgical removal of a renal cancer. In the characterisation of renal masses, a high rate of false negative results was observed, leading to a sensitivity, specificity and accuracy of 47%, 80% and 51% respectively, versus 97%, 0/5 and 83% respectively for CT. FDG PET detected all the sites of distant metastasis revealed by CT, as well as eight additional metastatic sites, leading to an accuracy of 94% versus 89% for CT. However, 36/53 patients (68%) did not have any distant metastasis on either CT or on PET. All but one of these patients had a low Fuhrman histological grade and a limited local stage (pT2). We conclude that FDG PET does not offer any advantage over CT for the characterisation of renal masses but that it appears to be an efficient tool for the detection of distant metastasis in renal cancer. However, our data suggest that a selection process could be implemented to determine which patients should undergo PET. FDG PET could be performed in the event of a solitary metastasis or doubtful images on CT. Selection could also be based on adverse histological findings from nephrectomy specimens in order to perform staging early after nephrectomy.