Improved survival after retrieval of 12 or more regional lymph nodes in appendiceal cancer.

BACKGROUND: To evaluate the role of regional lymph node (RLN) retrieval on stage migration, overall (OS), and cancer-specific survival (CSS) in appendiceal cancer. METHODS: Between 2004 and 2012, 1046 patients with primary stage I-III carcinoma of the appendix were identified in the Surveillance, Epidemiology and End Results database. The impact of the number of RLN removed on OS and CSS was assessed using joinpoint regression, Cox regression, and propensity score methods. RESULTS: The rate of node-positive cancer increased with the number of retrieved RLN from 10.5% in patients with one RLN removed to 30.6% in patients with 10 RLNs removed. This leveling off at 10 RLN was confirmed by joinpoint regression analysis (p = 0.023). Despite the finding that retrieval of 10 RLN should be sufficient for appendiceal cancer, for the survival analysis the somewhat higher cutoff of 12 RLN was applied, since this cutoff is recommended by the guidelines for colorectal cancer. Retrieval of 12 or more RLN was beneficial compared to less than 12 RLN retrieved for OS (HR = 0.60, p < 0.001) and CSS (HR = 0.67, p = 0.020) in multivariable analysis, as well as in propensity score matched analysis (OS: HR = 0.58, p = 0.001, CSS: HR = 0.61, p = 0.005). CONCLUSION: The rate of node-positive cancer increased with the number of retrieved RLN up to about 10 RLN (95%CI: 3.6-16.3, p = 0.023). Over 10 retrieved RLN, the node-positive cancer rate no longer increased. This correlates with the recommended number of 12 RLN to be retrieved in colorectal cancer, but differs from the guideline for neuroendocrine tumors.

Meta-analysis of the predictive value of C-reactive protein for infectious complications in abdominal surgery.

BACKGROUND: The aim of this analysis was to assess the predictive value of C-reactive protein (CRP) for the early detection of postoperative infectious complications after a variety of abdominal operations. METHODS: A meta-analysis of seven cohort studies from a single institution was performed. Laparoscopic gastric bypass and colectomies, as well as open resections of cancer of the colon, rectum, pancreas, stomach and oesophagus, were included. The predictive value of CRP was assessed by the area under the curve (AUC) of the receiver operating characteristic (ROC) curve. RESULTS: Of 1986 patients, 577 (29·1 (95 per cent c.i. 27·1 to 31·3) per cent) had at least one postoperative infectious complication. Patients undergoing laparoscopic gastric bypass (383 patients) or colectomy (285), and those having open gastric (97) or colorectal (934) resections were combined in a meta-analysis. Patients who had resection for cancer of the oesophagus (41) or pancreas (246) were analysed separately owing to heterogeneity. CRP levels 4 days after surgery had the highest diagnostic accuracy (AUC 0·76, 95 per cent c.i. 0·73 to 0·78). Sensitivity and specificity were 68·5 (60·6 to 75·5) and 71·6 (66·6 to 76·0) per cent respectively. Positive and negative predictive values were 50·4 (46·0 to 54·8) and 84·3 (80·8 to 87·3) per cent. The threshold CRP varied according to the procedure performed. CONCLUSION: The negative predictive value of serum CRP concentration on day 4 after surgery facilitates reliable exclusion of postoperative infectious complications.

Diagnosis and treatment of small follicular thyroid carcinomas.

BACKGROUND: Follicular thyroid microcarcinomas (mFTCs) of 10 mm or less in size rarely manifest clinically and their clinical significance is controversial. This study assessed their characteristics and incidence, and analysed treatment modalities used for mFTC. METHODS: Members of the German Association of Endocrine Surgeons were asked to review patients with mFTC operated on between 1990 and 2005. RESULTS: Data for 90 patients from 26 institutions were reported. Histopathological slides were available for re-evaluation in 35 patients. Most initial diagnoses had to be revised because of incorrect size assessment or incorrect diagnosis (benign adenoma, papillary thyroid carcinoma (PTC), follicular variant of PTC). The diagnosis of mFTC was confirmed in only four patients. As a result of the incorrect histopathological diagnosis, unnecessary completion thyroidectomy and radioiodine ablation were performed in 17 and 20 patients respectively. The incidence of mFTC was calculated to be 0.12 per million population per year. CONCLUSION: mFTC is exceptionally rare. Such tumours are overdiagnosed, resulting in unnecessary treatment associated with avoidable morbidity. Histopathological re-evaluation by an experienced pathologist is recommended before embarking on further treatments when a diagnosis of mFTC is made.

Rectocele and intussusception: is there any coherence in symptoms or additional pelvic floor disorders?

BACKGROUND: Patients with a rectocele often suffer from such symptoms as obstructed defaecation, urine or stool incontinence and pain. The aim of this study was to assess other concomitant pelvic floor disorders and their influence on pelvic function. METHODS: Included in the study were 37 female patients with a significant rectocele and defaecation disorder. Medical history and symptoms were analysed in terms of validated functional scores. All patients underwent open magnetic resonance defaecography (MRD) in a sitting position. Imaging was analysed for the presence and size of the rectocele, intussusception and other pelvic floor disorders. RESULTS: Patients with a higher body mass index tended to have a larger rectocele, whereas age and vaginal birth did not correlate with the size of the rectocele. In 67.5% of the patients with a previously diagnosed rectocele, an intussusception was diagnosed on MRD. This group suffered from significantly worse urine incontinence (p=0.023) and from accessory enteroceles 64%, compared with 17% (p=0.013) for those with a simple rectocele. Patients with higher grade intussusception suffered more frequently from incontinence than from constipation. CONCLUSION: Patients with a symptomatic rectocele frequently have other pelvic floor disorders that significantly influence the pattern of symptoms. Knowledge of all the afflictions is essential for determining the optimal treatment for each individual patient.

[Transplantation of porcine Langerhans islets for therapy of type I diabetes. The way to clinical application]. / Die Transplantation porciner Langerhans-Inseln zur Therapie des Typ-I-Diabetes. Der Weg zur klinischen Anwendung.

Transplantation of isolated pancreatic islets provides an interesting alternative to the present cure for diabetes: insulin injections and pumps. These are characterized by an insufficient glucose haemostasis and in the long run can induce kidney failure, blindness, heart failure, and amputations. Up to now more than 293 allogeneic islet transplantations have been performed in diabetics with chronical kidney failure. Despite some success, no real breakthrough has been yet achieved, though great efforts are being made to improve the various methodological steps on the way to clinical transplantation. The use of animal (xenogeneic) organs could be a solution to overcome the shortage of allogeneic donors. The current experimental and clinical research focuses on the use of pigs as organ donors, which have a number of advantages over the immunologically more compatible primates. This article reports on success and open questions concerning the efforts to isolate porcine islets for future clinical transplantation: the search for a suitable pig breed, the various isolation steps, purification and in vitro culture, transplantation models using-small and large animals, first clinical trials, and immunological reactions against the xenogeneic tissue. In addition, strategies to circumvent tissue rejection and future perspectives are discussed.

Loss of endogenous mouse mammary tumor virus superantigen increases tumor resistance.

From a cross between a tumor-susceptible mouse strain (DBA/2; D) and a tumor-resistant MHC-identical strain (B10.D2; D2) new recombinant inbred mouse strains were established over many generations of inbreeding and tumor resistance selection. Since resistance to the highly metastatic DBA/2 lymphoma variant ESb had an immunologic basis, and the two parental strains differed in endogenous viral superantigens (vSAGs), DNA of three D2 x D recombinant inbred mouse lines was typed for endogenous mouse mammary tumor viruses using mouse mammary tumor virus long terminal repeat- and env gene-specific probes. The resistant D2 x D mice were very similar to the susceptible parental strain D in their Mtv Southern blots, except for the lack of a single band corresponding to Mtv-7, the provirus coding for the strong DBA/2 superantigen Mls-1a. A backcross analysis revealed that Mtv-7-negative F2 mice were significantly more resistant than Mtv-7-positive F2 mice. When Mtv-7 was reintroduced into the resistant lines by crossing them with either CBA/J or BALB/D2.Mls-1a, the mice became again more tumor susceptible. Finally, we demonstrate the ability to transfer immunoresistance and graft-vs-leukemia reactivity from tumor-resistant to tumor-susceptible mice.

TCR-MHC class II interaction is required for peripheral expansion of CD4 cells in a T cell-deficient host.

It is well established that T cell-deficient nude and SCID mice can be reconstituted by i.v. injection of small numbers of purified peripheral CD4+ T cells; however, the requirements for expansion of the transferred T cells in such systems are not clear. We show here that blood and lymphoid organs of MHC class II-deficient mice (which selectively lack mature CD4+ T cells) cannot be reconstituted by transfer of purified splenic CD4+ T cells, whereas TCRalpha-deficient mice (which lack both CD4+ and CD8+ mature T cells) are readily reconstituted. The failure of CD4+ T cell reconstitution in MHC class II-deficient mice was not due to the presence of CD8+ T cells, since similar results were obtained in TCRalpha-MHC class II double-deficient mice. Consistent with most previous studies CD4+ T cells in reconstituted TCRalpha-deficient mice had a diverse TCR Vbeta repertoire and were predominantly of an activated/memory (CD44high) phenotype. Collectively our data demonstrate that the expansion of peripheral CD4+ T cells in a T cell-deficient host is dependent upon interactions of the TCR with MHC class II.

Lack of directed V alpha 14-J alpha 281 rearrangements in NK1+ T cells.

NK1.1+ T cells are an unusual subset of TCR alpha beta cells distinguished by their highly restricted V beta repertoire and predominant usage of an invariant V alpha 14-J alpha 281 chain. To assess whether a directed rearrangement mechanism could be responsible for this invariant alpha chain, we have analyzed V alpha 14 rearrangements by polymerase chain reaction and Southern blot in a panel of cloned T-T hybrids derived from thymic NK1.1+ T cells. As expected a high proportion (17/20) of the hybrids had rearranged V alpha 14 to J alpha 281. However, V alpha 14-J alpha 281 rearrangements always occurred on only one chromosome and were accompanied by other V alpha-J alpha rearrangements (not involving V alpha 14) on the homologous chromosome. These data argue that rigorous ligand selection rather than directed rearrangement is responsible for the high frequency of V alpha 14-J alpha 281 rearrangements in NK1.1+ T cells.

Natural killer-like T cells develop in SJL mice despite genetically distinct defects in NK1.1 expression and in inducible interleukin-4 production.

An unusual subset of mature T cells expresses natural killer (NK) cell-related surface markers such as interleukin-2 receptor beta (IL-2R beta; CD122) and the polymorphic antigen NK1.1. These "NK-like" T cells are distinguished by their highly skewed V alpha and V beta repertoire and by their ability to rapidly produce large amounts of IL-4 upon T cell receptor (TCR) engagement. The inbred mouse strain SJL (which expresses NK1.1 on its NK cells) has recently been reported to lack NK1.1+ T cells and consequently to be deficient in IL-4 production upon TCR stimulation. We show here, however, that SJL mice have normal numbers of IL-2R beta+ T cells with a skewed V beta repertoire characteristic of "NK-like" T cells. Furthermore lack of NK1.1 expression on IL-2R beta+ T cells in SJL mice was found by backcross analysis to be controlled by a single recessive gene closely linked to the NKR-P1 complex on chromosome 6 (which encodes the NK1.1 antigen). Analysis of a panel of inbred mouse strains further demonstrated that lack of NK1.1 expression on IL-2R beta+ T cells segregated with NKR-P1 genotype (as assessed by restriction fragment length polymorphism) and thus was not restricted to the SJL strain. In contrast, defective TCR induced IL-4 production (which appeared to be a unique property of SJL mice) seems to be controlled by two recessive genes unlinked to NKR-P1. Collectively, our data indicate that "NK-like" T cells develop normally in SJL mice despite genetically distinct defects in NK1.1 expression and inducible IL-4 production.

Expression pattern of extracellular matrix proteins in the pancreas of various domestic pig breeds, the Goettingen Minipig and the Wild Boar.

UNLABELLED: In spite of progress in biotechnology, isolation of porcine pancreatic islets remains a difficult task with unpredictable results. One reason could be the lack of knowledge as to the expression of extracellular matrix proteins in porcine exocrine and endocrine tissues, particularly in "islet capsules". Such proteins are subject to digestion by proteases, yet they might have a protective function for the fragile islets. OBJECTIVE: Of our study was a detailed histological analysis of the extracellular matrix proteins in various pig breeds. A broad panel of commercial, human-specific antibodies were used, since antibodies against porcine tissue were not available. METHODS: Frozen pancreatic tissue section of 7 domestic pig breeds, the Goettingen Minipig and the Wild Boar were stained with antibodies against collagen types I, II, III, IV, V, VI, VII, IX, laminin, fibronectin, vitronectin and elastin. Binding of antibodies was detected by immunoperoxidase and evaluated microscopically. Human and rat tissue was treated in the same way. RESULTS: (1) With the exception of anti-collagen type II, type VII and vitronectin, all antibodies revealed distinct binding patterns in the pancreas of the different pig breeds. However these antibodies bound on human cartilage and skin. (2) Collagen types I, III, IV, laminin and fibronectin are expressed on porcine pancreatic "islet capsules". (3) Expression levels of these proteins on "islet capsules" vary in the different pig breeds. However, no significant differences could be found in the expression pattern of collagen types I, III, IV, laminin and fibronectin, comparing domestic, experimental and wild type pigs. (4) Older individuals (Goettingen Minipig) appear to express higher levels of proteins on "islet capsules" than younger ones. CONCLUSIONS: Antibodies with specificity for human extracellular matrix proteins can be used successfully in the porcine pancreas. Thus, analysis of the structure and composition of porcine pancreatic tissue can be performed even without pig-specific antibodies. Particularly, the effects of various proteases and collagenases on the pancreatic tissue can now be monitored by immunohistochemical analysis allowing a rational design of protease mixtures for the isolation of pancreatic islets.

Lack of MMTV superantigen presentation in MHC class II-deficient mice.

Mammary tumor viruses (MMTVs) as well as their endogenous counterparts encode superantigens which react with T cells expressing particular T cell receptor V beta chains. Several lines of evidence indicated that MHC class II is required for the functional presentation of these superantigens. Here we provide direct proof that the function of superantigens is abrogated in the absence of MHC class II expression. No deletion of Mls-1-reactive T cells was observed in MHC class II-deficient mice, and splenocytes from these animals did not stimulate Mls-1-reactive T cell hybrids in vitro. Furthermore, the viral spread in MHC class II-deficient mice, maternally infected with MMTV(C3H), was severely reduced. While initial infection in the gut-associated lymphocytes was comparable between MHC class II-deficient and normal mice, the level of infection in the spleen and the mammary tissue was much lower in the deficient animals. Quantitation of proviral DNA in spleen revealed a direct correlation between the magnitude of superantigen stimulation and degree of infection. These experiments document the direct effect of superantigen stimulation on viral amplification.

B cells are essential for murine mammary tumor virus transmission, but not for presentation of endogenous superantigens.

Murine mammary tumor viruses (MMTVs) are retroviruses that encode superantigens capable of stimulating T cells via superantigen-reactive T cell receptor V beta chains. MMTVs are transmitted to the suckling offspring through milk. Here we show that B cell-deficient mice foster nursed by virus-secreting mice do not transfer infectious MMTVs to their offspring. No MMTV proviruses could be detected in the spleen and mammary tissue of these mice, and no deletion of MMTV superantigen-reactive T cells occurred. By contrast, T cell deletion and positive selection due to endogenous MMTV superantigens occurred in B cell-deficient mice. We conclude that B cells are essential for the completion of the viral life cycle in vivo, but that endogenous MMTV superantigens can be presented by cell types other than B cells.

Expression of Mtv-7 sag gene in vivo using a retroviral vector results in selective inactivation of superantigen reactive T cells.

T cells expressing specific TCR V beta chains are intrathymically eliminated in mice expressing the murine Mls (minor lymphocyte stimulating) superantigens. Recently, in vitro studies have shown that the endogenous mouse mammary tumor virus (MMTV)-7 sag gene encodes Mls-1 Ag. The demonstrated ability of MMTV superantigen proteins to react with TCRs has led to the postulate that other infectious retroviruses may use superantigen-like molecules to modify the host's immune system. In this report, successful retrovirus-mediated Mtv-7 sag gene transfer into pluripotent hematopoietic stem cells is described. In two different strains of Mls-1- host mice (CBA/Ca and BALB/c) reconstituted with Mtv-7 sag gene expressing bone marrow cells, low levels of ectopic Mtv-7 sag gene expression on syngeneic donor hematopoietic stem cell-derived population alone can induce partial clonal deletion of Mls-1 reactive V beta 6+ and V beta 8.1+ T cells, and complete clonal inactivation of V beta 8.1+ T cells.

The role of superantigens in the immunobiology of retroviruses.

Murine mammary tumour viruses (MMTVs) are retroviruses that encode superantigens capable of stimulating T cells via superantigen-reactive T cell receptor V beta chains. MMTVs are transmitted to the suckling offspring via the milk. We have established that class II and B cell-deficient mice that were foster nursed by virus-secreting mice do not transfer infectious MMTVs to their offspring. No MMTV proviruses could be detected in the spleen and mammary tissue of these mice and there was no deletion of MMTV superantigen-reactive T cells. These results confirm that superantigen expression in the context of MHC class II molecules is required for MMTV transmission. We conclude that B cells are essential for the completion of the viral life cycle in vivo. This indicates that B cells are infected first and that viral amplification takes place only if infected B cells present the MMTV superantigen on their surface which, in turn, results in activation of T cells expressing the appropriate T cell receptor V beta chains. These activated T cells stimulate B cells which enables viral replication. Human T cells carry all the structural features required for an efficient response to murine retrovirally encoded superantigens. Superantigen-like stimulation of human T cells has been demonstrated in both infectious and autoimmune diseases. Human immunodeficiency virus may encode a superantigen but this has not been proven.

Production and characterization of an Mls-1-specific monoclonal antibody.

Superantigens (SAGs) represent a new class of antigens, characterized as T cell receptor (TCR) V beta-reactive elements. Bacterial toxins constitute the major group of exogenous SAGs, while the mouse mammary tumor virus (MMTV)-encoded Mls molecules represent the endogenous SAGs. Mls-1 is the prototype of the latter SAGs, because it elicits a very potent T cell stimulatory response in vitro in unprimed T cells expressing the TCR V beta 6 or 8.1 chains. In vivo, Mls-1 causes deletion of immature T cells bearing the V beta 6, 7, 8.1, or 9 chains. Although Mls-1 was functionally discovered > 20 yr ago, it has not been possible to raise antibodies against this molecule. We have previously cloned and sequenced the Mtv-7 sag gene, which encodes Mls-1. Sequence comparisons with other MMTV sag genes suggested that the polymorphic 3' end encodes the TCR V beta specificity of these SAGs. We have, therefore, immunized hamsters with a 14-amino acid peptide from the deduced COOH-terminal sequence of the Mtv-7 sag gene. We describe here the production of a monoclonal antibody (mAb), 3B12, which is peptide specific and reacts with a recombinant baculovirus product of Mtv-7 sag. This mAb blocks Mls-1-specific T cell recognition and detects the Mls-1 protein on the surface of the B cell hybridoma LBB.A, but not on LBB.11, which is an Mtv-7 loss variant of LBB.A. Transfection of the Mtv-7 sag gene into LBB.11 renders this cell functionally Mls-1+ as well as positive for 3B12 binding, confirming the specificity of this mAb. It is well documented that B cells and CD8+ T cells express T cell stimulatory Mls-1 determinants, and we show here that this functional profile correlates with the expression of MMTV-specific mRNA. However, primary lymphocytes derived from Mls-1+ mice do not stain with 3B12, even after in vitro activation with mitogens or phorbol ester.