Microsatellite instability in colorectal cancer

BACKGROUND

Microsatellite instability (MSI) causes hereditary non-polyposis colorectal cancer (HNPCC), and occurs in about 15 per cent of sporadic colorectal cancers. Although the basic mechanisms are not clear, there is increased understanding of the clinicopathological consequences of MSI.

METHODS

Medline was searched for articles with a combination of keywords relating to MSI in colorectal cancer, focusing on molecular mechanisms, clinicopathological implications, and prognostic and predictive value. Emphasis was placed on articles from the past 5 years.

RESULTS

The genetic mechanisms differ in hereditary (germline mutation) and sporadic (epigenetic silencing) colorectal cancer. The MSI pathway frequently has altered transforming growth factor beta receptor II and BAX genes, often beta-catenin, and occasionally p16INK4A and PTEN. Changes in K-ras, adenomatous polyposis coli and p53 are rare. Polymerase chain reaction testing for MSI is superior to immunohistochemistry, but complicated by the number and types of nucleotide markers. The Bethesda panel guides HNPCC testing, but guidelines are lacking for general screening. The presence and role of low-frequency MSI remains controversial. Tumours with MSI tend to occur in the proximal colon and be large, but they have a good prognosis. Their reduced response to adjuvant chemotherapy requires confirmation.

CONCLUSION

Research on colorectal cancer needs to be stratified according to microsatellite status in order further to explore the molecular mechanisms and clinicopathological consequences of MSI.

Bile duct cysts in adults

BACKGROUND

Bile duct cysts are rare and of uncertain origin. Most have been reported in young females of Asian descent, but an increasing number have occurred in Western adults.

METHODS

A Medline literature search was performed to locate articles on the pathophysiological concepts, clinical behaviour and management controversies pertaining to bile duct cysts in adults. Emphasis was placed on reports from the past two decades.

RESULTS AND CONCLUSION

An increasing rate of occurrence of bile duct cyst is reported in adults. Type IV cysts are more frequent in adults than children. Presentation tends to be non-specific abdominal discomfort. Related hepatobiliary or pancreatic disease frequently precedes recognition, and may complicate the postoperative course. Surgical treatment aims to relieve complications deriving from the cysts and to reduce the significant risk of malignant change within the biliary tree. Complete cyst resection, cholecystectomy and Roux-en-Y hepaticojejunostomy reconstruction is standard. Controversy exists about the role of hepatic resection in type IV and V cysts, and the role of minimally invasive and laparoscopic treatment. In general, the outcome is good and a near-zero mortality rate has been reported in institutional series over the past decade.

Prenatal diagnosis of an isochromosome 5p in a fetus with increased nuchal translucency thickness and pulmonary atresia with hypoplastic right heart at 14 weeks

We report on a fetus presenting with increased nuchal translucency at 11 weeks' gestation, suggesting cystic hygroma. Chorion villous sampling was performed, and cytogenetic analysis revealed a supernumerary isochromosome 5p leading to tetrasomy 5p: 47,XX,+ i(5p)[7]/46,XX[5] after short-term culture and 47,XX,+ i(5p)[20] after long-term culture. Subsequent targeted sonographic follow-up at 12 and 14 weeks revealed further increase of the NT to 6.4 mm and the additional presence of a congenital heart defect (pulmonary atresia with intact ventricular septum). Termination of pregnancy was performed, and the heart defect was confirmed. Isochromosome 5p was found in varying proportions in all examined organs. Only a few cases of mosaic tetrasomy 5p have been reported in the literature, and recent reports on prenatally detected isochromosome 5p showed a possible relationship to increased nuchal translucency in some cases and also a possible role of confined mosaicism in others. Whereas cases with confined mosaicism did not show suspicious signs on ultrasound, true mosaicism conversely showed increased nuchal thickness as well as structural abnormalities. This is the first report on the association of a cardiac defect with this chromosome aberration.

Absent or hypoplastic thymus on ultrasound: a marker for deletion 22q11.2 in fetal cardiac defects

OBJECTIVE

Congenital heart defects (CHD), particularly conotruncal anomalies, may be associated with deletion of chromosome 22q11.2. Thymic aplasia or hypoplasia is known to be a typical feature in this condition. We aimed to establish (i) the prevalence of del22q11.2 in fetal CHD and (ii) whether ultrasound assessment of an absent or hypoplastic fetal thymus helps in preselection of a group who are at high risk for this deletion.

STUDY DESIGN

In fetuses (> 16 weeks) with CHD, karyotyping and fluorescence in situ hybridization for 22q11.2 were offered and the fetal thymus was evaluated sonographically.

RESULTS

One hundred and forty-nine fetuses with CHD and normal karyotype were analyzed. Seventy-six fetuses had conotruncal anomalies. 22q11.2 deletion was present in 10 cases (6.7%), all of which had conotruncal anomalies (13.1%). Thymic hypoplasia or absence was suspected in 11 cases with conotruncal anomaly. Nine of these 11 had the deletion; two cases were false positive. One fetus with a normal-sized thymus had deletion of 22q11.2 (sensitivity 90%, specificity 98.5%, positive predictive value 81.8%, and negative predictive value 99.2%). By subtype of cardiac anomaly, there was deletion in four of six fetuses with interruption of the aortic arch, two of four with absent pulmonary valve syndrome, three of nine with truncus arteriosus and one of 11 cases of tetralogy of Fallot. Pulmonary atresia with ventricular septal defect (n = 7), right-sided aortic arch (n = 4), transposition of the great arteries (n = 14), double outlet right ventricle (n = 13) and other complex malpositions of the great vessels (n = 8) were not associated with the deletion.

CONCLUSION

Thymic hypoplasia or aplasia may reliably be diagnosed during fetal echocardiography. The technique allows identification of a group at high risk for 22q11.2 deletion and is more specific and sensitive than by subtype of cardiac anomaly alone.

Prenatal diagnosis of 22q11 microdeletion in an early second-trimester fetus with conotruncal anomaly presenting with increased nuchal translucency and bilateral intracardiac echogenic foci

We report on a 16-week fetus, in which detection of increased nuchal translucency thickness and bilateral intracardiac echogenic foci led to the prenatal diagnosis of truncus arteriosus communis, interruption of the aortic arch and aplastic thymus. Cytogenetic examination confirmed a 22q11.2 microdeletion consistent with the suspected CATCH 22 syndrome. Subsequently hydrops fetalis developed and the fetus died in utero at 18 weeks. This case report supports the hypothesis that both cardiac failure and left ventricular outflow tract obstruction may cause increased nuchal translucency thickness. The association between increased nuchal translucency thickness and CATCH 22 syndrome should be considered in diagnostic procedures. The sonographic diagnosis of both increased nuchal translucency thickness and intracardiac echogenic foci requires specialist ultrasonography and echocardiography. In particular, identification of right-sided or bilateral echogenic foci should prompt further detailed examination.

Fetal autopsy: a review of recent developments

OBJECTIVE

To analyze recent changes in fetal autopsy in response to developments in prenatal medicine.

METHOD

During the period 1988 through 1997, 783 fetuses (75% induced abortions, 18% spontaneous abortions, and 7% stillbirths, all between the 12th and 40th week of gestation) with prenatally diagnosed congenital malformations and chromosomal aberrations were analyzed. We divided the autopsies into two periods: period A (1988-92, n=370) and period B (1993-97, n=413). All fetuses were analyzed before completion of 20 weeks of gestation. The malformations of the organ systems were presented according to their frequency for fetuses independent of the weeks of gestation.

RESULTS

An autopsy was performed prior to the completion of 20 weeks of gestation for 24% of the fetuses in period A and 45% in period B (P<0.0001). The number of diagnosed congenital heart malformations increased from 16% in period A to 23% in period B. The number of congenital heart malformations before completion of 20 weeks of gestation was only 21% in period A as compared to 42% in period B.

CONCLUSIONS

In period B, clinical questions were raised in a more concrete form and ultrasound images gave more detailed information than in period A. Access to prenatal findings prior to postmortem examination has helped investigators to develop a specific, clinically oriented, autopsy strategy based on the prenatal findings which makes it possible to diagnose very small malformations and to select sectional planes of special interest. The use of an interdisciplinary database is required for communication.

Fetal autopsy: the most important contribution of pathology in a center for perinatal medicine

OBJECTIVE

The aim of the current paper is to analyze the significant changes in fetal autopsy made by pathologists in a center for perinatal medicine in response to the recent rapid developments in prenatal medicine.

METHODS

We use our technical equipment (interdisciplinary databank, Intranet, fine instruments, imaging techniques) for prenatal diagnostics and fetal pathology in the Center for Perinatal Medicine at the Charité University Medical Center in Berlin, Germany.

RESULTS

Our technical setup has made it possible for us to plan autopsies in such a way that rare malformations in special cases can be documented in sectional planes corresponding to the prenatal sonographic images. Before the postmortem examination the pathologist receives all the prenatal findings obtained for the fetus and is able to examine the prenatal images on a monitor. The final diagnosis in the postmortem report includes the results of modern molecular pathology, clinical-genetic examination of the fetus, cytogenetic and molecular-cytogenetic findings and postmortem x-rays.

CONCLUSIONS

To be able to incorporate these various results into a final report in routine work the use of an interdisciplinary database is essential. Such a database also ensures faster and more productive interdisciplinary communication in a center of perinatal medicine.

Membrane-bound TNF supports secondary lymphoid organ structure but is subservient to secreted TNF in driving autoimmune inflammation

Mice without secreted TNF but with functional, normally regulated and expressed membrane-bound TNF (memTNF(Delta/Delta) mice) were created by knocking-in the uncleavable Delta 1-9,K11E TNF allele. In contrast to TNF-deficient mice (TNF(-/-)), memTNF supported many features of lymphoid organ structure, except generation of primary B cell follicles. Splenic chemokine expression was near normal. MemTNF-induced apoptosis was mediated through both TNF-R1 and TNF-R2. That memTNF is suboptimal for development of inflammation was revealed in experimental autoimmune encephalomyelitis. Disease severity was reduced in memTNF(Delta/Delta) mice relative to wild-type mice, and the nature of spinal cord infiltrates resembled that in TNF(-/-) mice. We conclude that memTNF supports many processes underlying lymphoid tissue structure, but secreted TNF is needed for optimal inflammatory lesion development.

Lymphotoxin controls alphaEbeta7-integrin expression by peripheral CD8+ T cells

Lymphotoxin (LT)-alpha, a member of the TNF family, is recognized as an important mediator in different aspects of lymphoid organ development. Targeted disruption of this molecule resulted in a substantial reduction in the proportion of alphaEbeta7-integrin(high) CD8+ T cells detectable in peripheral lymphoid organs. This defect, however, was not observed on mature CD4-CD8+ thymocytes. To determine whether this was due to downregulation of beta7-integrin expression by peripheral CD8+ T cells or a failure of thymic emigration of CD8+ beta7-integrin(high) T cells, beta7-integrin was examined on recent thymic emigrants (RTE). When analysed within 16 h after leaving the thymus CD4-CD8+ RTE in both LT-alpha-/- and wild type (wt) mice remained beta7-integrin(high) and were indistinguishable. However, within 3-5 days, emigration loss of beta7-integrin became evident in LT-alpha-/- mice. Despite this loss, the proportion of thymically derived alphabetaTCR+ T-cell populations in the intestinal epithelium, an important target tissue of CD8+ alphaEbeta7-integrin(high) T cells, was increased in the absence of LT-alpha. In contrast, B cells were detectable only rarely in the intestinal tissue of LT-alpha-/- mice. The expression of E-Cadherin remained unchanged. These results indicate that a LT-alpha-dependent process maintains a high level of alphaEbeta7-integrin expression by peripheral CD8+ T cells, and with this control mechanism LT-alpha may help to regulate CD8+ T-cell numbers in the tissues.

Perforated and non-perforated acute appendicitis--one disease or two entities?

OBJECTIVE

To analyse the pattern of clinical presentation of perforated and non-perforated acute appendicitis in 544 unselected patients treated surgically for suspected acute appendicitis; to find out if their presentation differed.

DESIGN

Open prospective population-based study.

SETTING

Teaching hospital, western Norway.

PATIENTS

All 434 patients operated on for suspected acute appendicitis from the catchment area of a single hospital in whom the diagnosis was confirmed.

INTERVENTIONS

Appendicectomy; history, clinical findings, and inflammatory markers were recorded in all patients.

MAIN OUTCOME MEASURES

Odds Ratio (OR) and 95% confidence interval (CI) obtained by logistic regression analysis of symptoms and signs of acute appendicitis with regard to independent predictors of perforation of the appendix. Receiver operating characteristic (ROC) curve analysis of inflammatory markers.

RESULTS

The perforation rate was 20% (n = 88). Perforation was unlikely when abdominal pain was limited to the right iliac fossa, (OR 0.13, 95% CI 0.05 to 0.33). Increased C-reactive protein (CRP) concentration >50 U/L (OR 4.6, 95% Cl 2.44 to 8.75) and greater age (by decade; OR 1.18, 95% CI 1.02 to 1.36) were independent predictors of perforation of the appendix.

CONCLUSIONS

Clinical differences between perforated and non-perforated acute appendicitis could be explained by the presence of advanced inflammation in patients with perforated appendicitis. Our data do not support the hypothesis that they are two clinically different diseases.

Stability in incidence of acute appendicitis. A population-based longitudinal study

BACKGROUND/AIM OF THE STUDY: During the past 50 years, a decrease in incidence of appendicitis has been reported. The various studies were retrospective and based on different data sources. In the present study, we analyze prospectively the incidence of acute appendicitis during a 10-year period in a well defined population of 265,000.

METHODS

Prospective registration of all operations performed in patients with suspected acute appendicitis in the catchment area of a single institution. The diagnosis of acute appendicitis was based on histology in all cases. The annual incidence of acute appendicitis was calculated with regard to nonperforated and perforated acute appendicitis.

MAIN RESULTS

Between 1989 and 1998, 2,861 patients underwent surgery for suspected acute appendicitis. In 2,232 (78%) patients, acute appendicitis was confirmed histologically. Mean annual incidence was 84/100,000 (95% confidence interval 80 to 88/100,000). Crude incidence remained stable during the study period, with the exception of a significant increase in 1991 followed by a significant decrease the next year. Nonperforated acute appendicitis showed a different incidence pattern as compared to perforated acute appendicitis.

CONCLUSION

In our prospective study, the incidence of acute appendicitis remained stable in our well-defined study population during the study period of 10 years. This is in contrast to the majority of studies during the last decades.

Rapidly fatal leishmaniasis in resistant C57BL/6 mice lacking TNF

The resolution of infections with the protozoan parasite Leishmania major in mice requires a Th1 response that is closely associated with the expression of IL-12, IFN-gamma, and inducible NO synthase. Previous Ab neutralization studies or the use of mice deficient for both TNF receptors suggested that TNF plays only a limited role in the control of parasite replication in vivo. In this study we demonstrate that resistant C57BL/6 (B6.WT) mice locally infected with L. major rapidly succumb to progressive visceral leishmaniasis after deletion of the TNF gene by homologous recombination. A reduction of the parasite inoculum to 3000 promastigotes did not prevent the fatal outcome of the disease. An influence of the altered morphology of secondary lymphoid organs in C57BL/6-TNF(-/-) (B6.TNF(-/-)) mice on the course of disease could be excluded by the generation of reciprocal bone marrow chimeras. Although infected B6.TNF(-/-) mice mounted an L. major-specific IFN-gamma response and expressed IL-12, the onset of the immune reaction was delayed. After in vitro stimulation, B6.TNF(-/-) inflammatory macrophages released 10-fold less NO in response to IFN-gamma than B6.WT cells. However, in the presence of a costimulus, e.g., L. major infection or LPS, the production of NO by B6.WT and B6.TNF(-/-) macrophages was comparable. In vivo, inducible NO synthase protein was readily detectable in skin lesions and draining lymph nodes of B6.TNF(-/-) mice, but its expression was more disperse and less focal in the absence of TNF. These are the first data to demonstrate that TNF is essential for the in vivo control of L. major.

The history is important in patients with suspected acute appendicitis

BACKGROUND/AIMS

The clinical diagnosis of acute appendicitis is incorrect in 20-30% of patients undergoing surgery. We analysed the clinical importance of nine commonly used symptoms and signs in 544 consecutive patients with regard to the correct diagnosis of acute appendicitis.

METHODS

Open population-based prospective study. The degree of the surgeon's certainty of the preoperative diagnosis was assessed. The final diagnosis was based on histology. Logistic regression was used to analyze the independent value of nine symptoms and signs to predict acute appendicitis by calculating odds ratio (OR) with 95% confidence intervals (CI).

RESULTS

In 434 of 544 patients (80%) acute appendicitis was confirmed. A history of nausea or vomiting (OR = 2.3; CI = 1.11 to 4.76) and pain migration to right iliac fossa (OR = 1.9; CI = 1.12 to 3.22) were significant predictors of acute appendicitis. Pain migration was found to be an independent predictor in females and nausea or vomiting in males. In the group of patients (29%) with an uncertain preoperative diagnosis, pain migration predicted a correct diagnosis in females (OR = 4.7; CI = 1.2 to 18), while tenderness over McBurney's point was a significant predictor in males (OR = 8.3; CI = 1.1 to 63).

CONCLUSIONS

A history of pain migration and nausea or vomiting were independent predictors for the correct diagnosis of acute appendicitis in patients undergoing surgery. Thus, patient history is important in this patient group.

Recirculating and marginal zone B cell populations can be established and maintained independently of primary and secondary follicles

In normal spleen, most recirculating naïve IgM+IgDhi B cells are located within primary follicles and mantle zones of secondary follicles. By contrast, the marginal zone contains a heterogeneous population of IgMhiIgDlo/- B cells that are mostly non-recirculating. Although these are dynamic populations they are maintained at a constant size, the fundamental homeostatic mechanisms remain uncertain. One possibility is that the presence and turnover of each of the B cell populations is dependent on their location within discrete splenic compartments. To investigate this, we have characterized immature, non-recirculating, mature recirculating, marginal zone and B-1 cell populations in TNF-/- and TNF/lymphotoxin(LT)-alpha-/- mice that have disorganized splenic architecture. Labelling with 5-bromo-2'-deoxyuridine revealed that turnover of B cells in TNF-/- mice is normal, but is diminished in TNF/LT-alpha-/- mice. The recirculating B cell populations in both mutant strains are normal in proportion and phenotype. Marginal zone B cells are not seen in TNF/LT-alpha-/- mice, but this population appears normal in TNF-/- mice, even though they lack germinal centres. These findings indicate that peripheral B cell subsets can be established and maintained independently of normal follicular architecture.

Structural investigations of the CuA centre of nitrous oxide reductase from Pseudomonas stutzeri by site-directed mutagenesis and X-ray absorption spectroscopy

Nitrous oxide reductase is the terminal component of a respiratory chain that utilizes N2O in lieu of oxygen. It is a homodimer carrying in each subunit the electron transfer site, CuA, and the substrate-reducing catalytic centre, CuZ. Spectroscopic data have provided robust evidence for CuA as a binuclear, mixed-valence metal site. To provide further structural information on the CuA centre of N2O reductase, site directed mutagenesis and Cu K-edge X-ray absorption spectroscopic investigation have been undertaken. Candidate amino acids as ligands for the CuA centre of the enzyme from Pseudomonas stutzeri ATCC14405 were substituted by evolutionary conserved residues or amino acids similar to the wild-type residues. The mutations identified the amino acids His583, Cys618, Cys622 and Met629 as ligands of Cu1, and Cys618, Cys622 and His626 as the minimal set of ligands for Cu2 of the CuA centre. Other amino acid substitutions indicated His494 as a likely ligand of CuZ, and an indirect role for Asp580, compatible with a docking function for the electron donor. Cu binding and spectroscopic properties of recombinant N2O reductase proteins point at intersubunit or interdomain interaction of CuA and CuZ. Cu K-edge X-ray absorption spectra have been recorded to investigate the local environment of the Cu centres in N2O reductase. Cu K-edge Extended X-ray Absorption Fine Structure (EXAFS) for binuclear Cu chemical systems show clear evidence for Cu backscattering at approximately 2.5 A. The Cu K-edge EXAFS of the CuA centre of N2O reductase is very similar to that of the CuA centre of cytochrome c oxidase and the optimum simulation of the experimental data involves backscattering from a histidine group with Cu-N of 1.92 A, two sulfur atoms at 2.24 A and a Cu atom at 2. 43 A, and allows for the presence of a further light atom (oxygen or nitrogen) at 2.05 A. The interpretation of the CuA EXAFS is in line with ligands assigned by site-directed mutagenesis. By a difference spectrum approach, using the Cu K-edge EXAFS of the holoenzyme and that of the CuA-only form, histidine was identified as a major contributor to the backscattering. A structural model for the CuA centre of N2O reductase has been generated on the basis of the atomic coordinates for the homologous domain of cytochrome c oxidase and incorporating our current results and previous spectroscopic data.

Immune down-regulation and peripheral deletion of CD8 T cells does not require TNF receptor-ligand interactions nor CD95 (Fas, APO-1)

TNF receptor-ligand interactions and CD95 (Fas / APO-1) have been demonstrated to be involved in activation-induced death of mature T cells. Here, we examined the role of these molecules in the murine model of lymphocytic choriomeningitis virus (LCMV) infection using LCMV TCR transgenic (tg) mice lacking TNF, TNF receptor I (TNFR1), CD95 or both TNFR1 and CD95. This report demonstrates that neither TNF receptor-ligand interactions nor CD95 was required for down-regulation of LCMV-specific CD8 T cells following acute LCMV infection in vivo. Even LCMV-specific CD8 T cells lacking both TNFR1 and CD95 molecules declined after the acute phase of the infection with normal kinetics. Furthermore, peripheral deletion of LCMV-specific CD8 T cells induced by LCMV peptide injection or by adoptive transfer of tg spleen cells expressing the corresponding LCMV epitope was not impaired in mice lacking TNF, TNFR1 and / or CD95. Our data speak against an indispensable role of these molecules in antigen-induced apoptosis of CD8 T cells in vivo and suggest that T cell homeostasis after antigen challenge is controlled by additional mechanisms.

Tumor necrosis factor sustains the generalized lymphoproliferative disorder (gld) phenotype

Tumor necrosis factor (TNF) and Fas ligand (FasL) play major roles in the homeostasis of the peripheral immune system. This becomes dramatically obvious in the absence of a functional FasL. Mice with such a deficiency develop a profound lymphadenopathy, splenomegaly, hypergammaglobulinemia, and strain-dependent systemic autoimmune disease, and succumb to premature death. It is consequently termed generalized lymphoproliferative disorder (gld). By contrast, TNF deficiency alone does not result in a striking phenotype. Thus, we sought to determine what role TNF might play in contributing to the gld phenotype by creating C57BL/6.gld.TNF(-/-) mice. Contrary to the expected outcome, mice deficient for both FasL and TNF had a substantially milder gld phenotype with regard to mortality, lymphoaccumulation, germinal center formation, and hypergammaglobulinemia. To confirm these data in a strain highly permissive for the phenotype, C3H/HeJ.gld and C3H.HeJ.lpr mice were treated with a TNF-specific monoclonal antibody. This transient neutralization of TNF also resulted in a significantly attenuated lymphoproliferative phenotype. We conclude that TNF is necessary for the full manifestation of the lymphoproliferative disorder, in particular playing a critical role in lymphoaccumulation. Most importantly, absence of TNF protects gld mice against premature death.

[Prenatal diagnosis of heart defects and associated chromosomal aberrations]

AIM

According to epidemiological studies on newborns, the association of congenital heart defects with chromosomal anomalies varies between 4 and 12%. Prenatally this rate is probably higher, due to antenatal death occurring in fetuses with chromosomal aberrations. The aim of the study was therefore to determine the rate and the distribution of chromosomal aberrations in prenatally detected heart defects.

PATIENTS AND METHOD

Within a period of 7 years fetal echocardiography was performed on 2716 fetuses at high risk for CHD. The analysis of the fetal heart was achieved by the visualization of different planes. Once a heart defect was detected, karyotyping was performed after amniocentesis, cordocentesis or chorion villous sampling, or in a few cases postnatally from cord blood. Prenatal ultrasound findings were confirmed postnatally by ultrasound examination or, in case of abortion, stillbirth or neonatal death, by autopsy.

RESULTS

A total of 203 fetal heart malformations were detected and 46 of them (22%) had associated chromosomal anomalies. 60% of all cases and 80% of the study group had extracardiac anomalies. Only eight out of the 46 pregnant women (17.5%) were older than 35 years. Eight out of the 15 fetuses with trisomy 18 had a ventricular septal defect, 9/13 fetuses with trisomy 21 had an atrioventricular septal defect and all 5 fetuses with monosomy X had a left heart outflow obstruction. No typical cardiac defects were found in the remaining 13 fetuses (5 trisomy 13, 2 triploidies, 6 miscellaneous). Of the 13 live births (23 terminations of pregnancy and 10 intrauterine deaths) 6 children survived (46% and overall survival rate 13%). The following rates of associations with aneuploidies were found: atrioventricular septal defect 55%, ventricular septal defect and aortic coaction both 43%, tetralogy of Fallot and double outlet right ventricle both 36%. In comparison, fetuses with isomerism, transposition of the great arteries and pulmonary atresia or stenosis had normal chromosomes.

CONCLUSION

We conclude that the rate of association of heart defects and chromosomal abnormalities is higher prenatally than in the neonatal period and is approximately 22%. After detecting a fetal cardiac malformation, karyotyping is mandatory for the further management of pregnancy. The likelihood of detection of an aneuploidy increases when some typical heart defects are detected or when an association with extracardiac anomalies is found.

Adenovirus-induced liver pathology is mediated through TNF receptors I and II but is independent of TNF or lymphotoxin

Mice infected with an adenovirus mutant in which the E3 region is deleted, including TNF-resistance genes, develop fatal liver pathology within 3-4 days after infection. At least 10-fold more wild-type virus was needed to cause comparable pathology. These results indicate that the E3 region is critically involved in modulating the pathogenesis of adenovirus infection and that TNF may play a role in liver damage. To explore the latter possibility, the course of disease was examined in infected mice lacking TNFR-I and/or TNFRII, TNF only, or both TNF and lymphotoxin-alpha. Only mice lacking both TNFRI and TNFRII were protected from the lethal affects of the mutant adenovirus. Mice deficient in TNF or TNF and lymphotoxin-alpha displayed the fatal pathology. This outcome is consistent with the existence of another related ligand that binds TNFRI/II to mediate liver damage during infection with this mutant.

Induction of intratumoral tumor necrosis factor (TNF) synthesis and hemorrhagic necrosis by 5,6-dimethylxanthenone-4-acetic acid (DMXAA) in TNF knockout mice

5,6-Dimethylxanthenon-4-acetic acid (DMXAA) is a new antitumor drug currently undergoing clinical trial. Administration of DMXAA to mice with tumors leads to cessation of tumor blood flow and the onset of tumor hemorrhagic necrosis, accompanied by the production of the cytokine tumor necrosis factor (TNF). Previous studies have shown that DMXAA induces both tumor and host cells to synthesize TNF and that induced intratumoral TNF production correlates with the antitumor activity of DMXAA. To explore the hypothesis that TNF production by tumor cells contributed to the induction of hemorrhagic necrosis by DMXAA, TNF-/- (C57Bl/6 background) mice were used as recipients for the s.c. implantation of (TNF positive) colon 38 adenocarcinoma. Tumors removed 24 h after treatment with DMXAA (66 or 100 micromol/kg) were found to be hemorrhagic and necrotic. Cells expressing TNF mRNA in tumors removed 2 h after treatment with DMXAA (160 micromol/kg) were found by in situ hybridization to be comparable in frequency and distribution with those in tumors from C57Bl/6 TNF-positive mice. However, the amount of TNF protein extracted from tumors from TNF knockout mice was lower than that from TNF-positive mice. Spleen and liver tissue from TNF knockout mice, in contrast to that from TNF-positive mice, produced no TNF mRNA. TNF protein was undetectable in liver and spleen tissue from TNF knockout mice, but was evident in tissue from TNF-positive mice. These results confirm that DMXAA has the novel ability of inducing tumors to synthesize TNF in situ.

Diagnostic accuracy of inflammatory markers in patients operated on for suspected acute appendicitis: a receiver operating characteristic curve analysis

OBJECTIVE

To analyse the diagnostic accuracy of inflammatory variables in patients operated on for suspected acute appendicitis.

DESIGN

Open prospective population based study.

SETTING

Teaching hospital, Norway.

INTERVENTIONS

Appendicectomy in 544 patients with clinically suspected acute appendicitis.

MAIN OUTCOME MEASURES

Diagnostic accuracy of inflammatory variables using receiver operating characteristic (ROC) curve analysis. Logistic regression model of inflammatory variables using results of ROC-analysis.

RESULTS

A small area under the ROC curve (AUC) (between 0.56 and 0.69) indicated less diagnostic accuracy. The best cut-off values were associated with low sensitivity and specificity, varying from 46% to 88%. Age, duration of history, and histological grade of inflammation significantly influenced the test results (AUC >0.5). The white cell count (WCC) and C-reactive protein (CRP) concentration were independent predictors of acute appendicitis with cut-off values of >12.3x10(9)/L and >0 mg/L, respectively, but AUC values of over 0.5 were observed only in patients between 13 and 40 years of age.

CONCLUSION

Inflammatory variables added information of limited value in the diagnosis of suspected acute appendicitis. The test results should be interpreted differently in different groups of patients.