Development of the foregut and the formation of the trachea and esophagus in rat embryos. A symphony of confusion

Introduction: During embryonic development, the trachea emerges from an area of the foregut, which is often referred to as "anterior" or "common" foregut tube or simply foregut. To explain this process of differentiation, four competing models exist to date. The outgrowth and watershed models propose a foregut that remains constant in length. In the outgrowth model, the trachea buds off and elongates from the foregut, while in the watershed model, a mesenchymal wedge splits the growing foregut into the trachea and esophagus. In contrast, the septation model proposes a cranial splitting and thus a shortening of the "common" foregut tube into the trachea and esophagus by an emerging septum. Finally, the splitting and extension model describes an interaction of cranial splitting of the foregut and simultaneous caudal tracheal and esophageal growth. Methods: Here we examine the development of the undifferentiated foregut by micro computed tomography, which allows precise measurements. Results: Our results show that this area of the foregut transforms into the larynx, a process, which is independent from tracheal and esophageal development. Discussion: These observations are only consistent with the outgrowth model.

Perioperative or only adjuvant gemcitabine plus nab-paclitaxel for resectable pancreatic cancer (NEONAX)-a randomized phase II trial of the AIO pancreatic cancer group

BACKGROUND

Data on perioperative chemotherapy in resectable pancreatic ductal adenocarcinoma (rPDAC) are limited. NEONAX examined perioperative or adjuvant chemotherapy with gemcitabine plus nab-paclitaxel in rPDAC (National Comprehensive Cancer Network criteria).

PATIENTS AND METHODS

NEONAX is a prospective, randomized phase II trial with two independent experimental arms. One hundred twenty-seven rPDAC patients in 22 German centers were randomized 1 : 1 to perioperative (two pre-operative and four post-operative cycles, arm A) or adjuvant (six cycles, arm B) gemcitabine (1000 mg/m2) and nab-paclitaxel (125 mg/m2) on days 1, 8 and 15 of a 28-day cycle.

RESULTS

The primary endpoint was disease-free survival (DFS) at 18 months in the modified intention-to-treat (ITT) population [R0/R1-resected patients who started neoadjuvant chemotherapy (CTX) (A) or adjuvant CTX (B)]. The pre-defined DFS rate of 55% at 18 months was not reached in both arms [A: 33.3% (95% confidence interval [CI] 18.5% to 48.1%), B: 41.4% (95% CI 20.7% to 62.0%)]. Ninety percent of patients in arm A completed neoadjuvant treatment, and 42% of patients in arm B started adjuvant chemotherapy. R0 resection rate was 88% (arm A) and 67% (arm B), respectively. Median overall survival (mOS) (ITT population) as a secondary endpoint was 25.5 months (95% CI 19.7-29.7 months) in arm A and 16.7 months (95% CI 11.6-22.2 months) in the upfront surgery arm. This difference corresponds to a median DFS (mDFS) (ITT) of 11.5 months (95% CI 8.8-14.5 months) in arm A and 5.9 months (95% CI 3.6-11.5 months) in arm B. Treatment was safe and well tolerable in both arms.

CONCLUSIONS

The primary endpoint, DFS rate of 55% at 18 months (mITT population), was not reached in either arm of the trial and numerically favored the upfront surgery arm B. mOS (ITT population), a secondary endpoint, numerically favored the neoadjuvant arm A [25.5 months (95% CI 19.7-29.7months); arm B 16.7 months (95% CI 11.6-22.2 months)]. There was a difference in chemotherapy exposure with 90% of patients in arm A completing pre-operative chemotherapy and 58% of patients starting adjuvant chemotherapy in arm B. Neoadjuvant/perioperative treatment is a novel option for patients with resectable PDAC. However, the optimal treatment regimen has yet to be defined. The trial is registered with ClinicalTrials.gov (NCT02047513) and the European Clinical Trials Database (EudraCT 2013-005559-34).

Thoracoscopic Guided Pericostal Sutures as a Solid Fixation for Primary Closure of Congenital Diaphragmatic Hernias

Purpose: To describe a minimally invasive technique with primary closure and strong suture connection that is feasible in cases of larger, most common type B defects of congenital diaphragmatic hernia (CDH). Background: The thoracoscopic approach (TA) is a favorable technique for the repair of CDH and is still evolving globally. A common issue is finding the optimal suture technique for secure closure in order to prevent recurrences. Whether a defect can be closed only by sutures or by using a patch depends on the size of CDH, the presence of a muscular rim along the inner thoracic surface and finally on the surgeon’s experience. From a geometrical point of view, the challenge is to transform the circular defect into a line, without tension, with a strong compound and preferably without additional material. To address this, we apply a setting of the sutures in a “T-shape” and a way to lead the sutures around the rib bones in order to increase stability. This method allows for the primary closure of CDHs and also applies to larger defects. Cases: We present seven newborns with posterolateral CDH on the left side. The defects were solely repaired by TA and by the suturing technique described in detail.

Rational design, synthesis and testing of novel tricyclic topoisomerase inhibitors for the treatment of bacterial infections part 1

The alarming reduction in drug effectiveness against bacterial infections has created an urgent need for the development of new antibacterial agents that circumvent bacterial resistance mechanisms. We report here a series of DNA gyrase and topoisomerase IV inhibitors that demonstrate potent activity against a range of Gram-positive and selected Gram-negative organisms, including clinically-relevant and drug-resistant strains. In part 1, we present a detailed structure activity relationship (SAR) analysis that led to the discovery of our previously disclosed compound, REDX05931, which has a minimum inhibitory concentration (MIC) of 0.06 μg mL^-1 against fluoroquinolone-resistant Staphylococcus aureus. Although in vitro hERG and CYP inhibition precluded further development, it validates a rational design approach to address this urgent unmet medical need and provides a scaffold for further optimisation, which is presented in part 2.

Association of infra-patellar fat pad size with age and body weight in children and adolescents

BACKGROUND

The infra-patellar fat pad (IPFP) represents a potential mediator between obesity, low grade inflammation, and knee osteoarthritis via endocrine pathways. Yet, not only in adults, but also in childhood obesity negatively impacts knee structures.

OBJECTIVE

The current study therefore investigated the sex-specific growth of the IPFP with age and body weight in healthy children and adolescents.

MATERIALS AND METHODS

Thirty young healthy subjects (60% girls; age 4-17 years, body weight 14-90 kg in girls and 29-105 kg in boys; BMI 12.2-32.4 kg/m²) without magnetic resonance imaging (MRI) knee pathology were studied. The IPFP volume was determined from sagittal T-1 weighted and proton-density spectral attenuated inversion recovery MRIs. The primary analysis focused on the sex-specific IPFP volume/body weight ratio as dependent, and age as independent variable, using linear regression models. A secondary analytic focus was the slope of the age-dependence of IPFP volume, without normalization to body weight.

RESULTS

There was no statistically significant association of the IPFP volume/body weight ratio with age in girls (p = 0.57) or boys (p = 0.31), the R² of ranging from -0.32 to 0.14. The ratio was greater in boys (0.54 ± 0.10 cm³/kg) than in girls (0.45 ± 0.07 cm³/kg) (p < 0.01). The IPFP volume increased by approx. 2 cm³ per annum in both girls and boys, without any indication of a non-linear relationship.

CONCLUSION

Our findings reveal that the ratio of the IPFP volume and body weight remains constant between age 4 and 17 in both normal weight girls and boys, and that the IPFP volume increases linearly with age throughout this period.

ACE phenotyping in Gaucher disease

BACKGROUND

Gaucher disease is characterized by the activation of splenic and hepatic macrophages, accompanied by dramatically increased levels of angiotensin-converting enzyme (ACE). To evaluate the source of the elevated blood ACE, we performed complete ACE phenotyping using blood, spleen and liver samples from patients with Gaucher disease and controls.

METHODS

ACE phenotyping included 1) immunohistochemical staining for ACE; 2) measuring ACE activity with two substrates (HHL and ZPHL); 3) calculating the ratio of the rates of substrate hydrolysis (ZPHL/HHL ratio); 4) assessing the conformational fingerprint of ACE by evaluating the pattern of binding of monoclonal antibodies to 16 different ACE epitopes.

RESULTS

We show that in patients with Gaucher disease, the dramatically increased levels of ACE originate from activated splenic and/or hepatic macrophages (Gaucher cells), and that both its conformational fingerprint and kinetic characteristics (ZPHL/HHL ratio) differ from controls and from patients with sarcoid granulomas. Furthermore, normal spleen was found to produce high levels of endogenous ACE inhibitors and a novel, tightly-bound 10-30 kDa ACE effector which is deficient in Gaucher spleen.

CONCLUSIONS

The conformation of ACE is tissue-specific. In Gaucher disease, ACE produced by activated splenic macrophages differs from that in hepatic macrophages, as well as from macrophages and dendritic cells in sarcoid granulomas. The observed differences are likely due to altered ACE glycosylation or sialylation in these diseased organs. The conformational differences in ACE may serve as a specific biomarker for Gaucher disease.

Laparoscopic Management of Autoamputated Ovary in Newborns: A Report of 2 Cases

Intrauterine autoamputation of the ovary is an extremely rare diagnosis in the pediatric population. The current literature is limited to contradictory recommendations, while a standard management protocol for autoamputated adnexa secondary to intrauterine ovarian torsion is yet to be established. We report 2 cases of auto-amputation of the ovary, leading to a free-floating intra-abdominal cyst in the newborn. Laparoscopic management was successful in both cases.

Regenerative capacity of the enteric nervous system: is immaturity defining the point of no return?

BACKGROUND

Intestinal obstruction in newborns is associated with intestinal motility disorders after surgery. Alterations in the enteric nervous system (ENS) might cause abnormal peristalsis, which may then result in intestinal motility disorders. We aimed to quantify alterations in the myenteric plexus after a ligation and to test if these alterations were reversible.

METHODS

Small intestines of chicken embryos were ligated in ovo at embryonic day (ED) 11 for either 4 d (ED 11-15) or 8 d (ED 11-19). Both treated groups and control group were sacrificed and intestinal segments examined by means of both light and electron microscopy.

RESULTS

The number of proximal myenteric ganglia increased (ED 19, 30.7 ± 3.16 versus 23.1 ± 2.03; P < 0.001) in the 8-d ligature group but had values similar to the control group in the 4-d ligature group. The size distribution was skewed toward small ganglia in the 8-d ligature group (ED 19, 83.71 ± 11.60% versus 3.88 ± 4.74% in the control group; P < 0.001) but comparable with the control group in the 4-d ligature group. Subcellular alterations in the 4-d ligature group were reversible.

CONCLUSIONS

The pathologic alterations in the ENS were fully reversible in the 4-d ligature group. This reversibility might be linked to the degree of immaturity of the ENS.

Age-related gene expression analysis in enteric ganglia of human colon after laser microdissection

The enteric nervous system (ENS) poses the intrinsic innervation of the gastrointestinal tract and plays a critical role for all stages of postnatal life. There is increasing scientific and clinical interest in acquired or age-related gastrointestinal dysfunctions that can be manifested in diseases such as gut constipation or fecal incontinence. In this study, we sought to analyze age-dependent changes in the gene expression profile of the human ENS, particularly in the myenteric plexus. Therefore, we used the laser microdissection technique which has been proven as a feasible tool to analyze distinct cell populations within heterogeneously composed tissues. Full biopsy gut samples were prepared from children (4-12 months), middle aged (48-58 years) and aged donors (70-95 years). Cryosections were histologically stained with H&E, the ganglia of the myenteric plexus identified and RNA isolated using laser microdissection technique. Quantitative PCR was performed for selected neural genes, neurotransmitters and receptors. Data were confirmed on protein level using NADPH-diaphorase staining and immunohistochemistry. As result, we demonstrate age-associated alterations in site-specific gene expression pattern of the ENS. Thus, in the adult and aged distal parts of the colon a marked decrease in relative gene expression of neural key genes like NGFR, RET, NOS1 and a concurrent increase of CHAT were observed. Further, we detected notable regional differences of RET, CHAT, TH, and S100B comparing gene expression in aged proximal and distal colon. Interestingly, markers indicating cellular senescence or oxidative stress (SNCA, CASP3, CAT, SOD2, and TERT) were largely unchanged within the ENS. For the first time, our study also describes the age-dependent expression pattern of all major sodium channels within the ENS. Our results are in line with previous studies showing spatio-temporal differences within the mammalian ENS.

In vivo transplantation of neurosphere-like bodies derived from the human postnatal and adult enteric nervous system: a pilot study

Recent advances in the in vitro characterization of human adult enteric neural progenitor cells have opened new possibilities for cell-based therapies in gastrointestinal motility disorders. However, whether these cells are able to integrate within an in vivo gut environment is still unclear. In this study, we transplanted neural progenitor-containing neurosphere-like bodies (NLBs) in a mouse model of hypoganglionosis and analyzed cellular integration of NLB-derived cell types and functional improvement. NLBs were propagated from postnatal and adult human gut tissues. Cells were characterized by immunohistochemistry, quantitative PCR and subtelomere fluorescence in situ hybridization (FISH). For in vivo evaluation, the plexus of murine colon was damaged by the application of cationic surfactant benzalkonium chloride which was followed by the transplantation of NLBs in a fibrin matrix. After 4 weeks, grafted human cells were visualized by combined in situ hybridization (Alu) and immunohistochemistry (PGP9.5, GFAP, SMA). In addition, we determined nitric oxide synthase (NOS)-positive neurons and measured hypertrophic effects in the ENS and musculature. Contractility of treated guts was assessed in organ bath after electrical field stimulation. NLBs could be reproducibly generated without any signs of chromosomal alterations using subtelomere FISH. NLB-derived cells integrated within the host tissue and showed expected differentiated phenotypes i.e. enteric neurons, glia and smooth muscle-like cells following in vivo transplantation. Our data suggest biological effects of the transplanted NLB cells on tissue contractility, although robust statistical results could not be obtained due to the small sample size. Further, it is unclear, which of the NLB cell types including neural progenitors have direct restoring effects or, alternatively may act via 'bystander' mechanisms in vivo. Our findings provide further evidence that NLB transplantation can be considered as feasible tool to improve ENS function in a variety of gastrointestinal disorders.

Risk for transmission of Naegleria fowleri from solid organ transplantation

Primary amebic meningoencephalitis (PAM) caused by the free-living ameba (FLA) Naegleria fowleri is a rare but rapidly fatal disease of the central nervous system (CNS) affecting predominantly young, previously healthy persons. No effective chemotherapeutic prophylaxis or treatment has been identified. Recently, three transplant-associated clusters of encephalitis caused by another FLA, Balamuthia mandrillaris, have occurred, prompting questions regarding the suitability of extra-CNS solid organ transplantation from donors with PAM. During 1995-2012, 21 transplant recipients of solid organs donated by five patients with fatal cases of PAM were reported in the United States. None of the recipients developed PAM, and several recipients tested negative for N. fowleri by serology. However, historical PAM case reports and animal experiments with N. fowleri, combined with new postmortem findings from four patients with PAM, suggest that extra-CNS dissemination of N. fowleri can occur and might pose a risk for disease transmission via transplantation. The risks of transplantation with an organ possibly harboring N. fowleri should be carefully weighed for each individual recipient against the potentially greater risk of delaying transplantation while waiting for another suitable organ. In this article, we present a case series and review existing data to inform such risk assessments.

Vascular endothelial growth factor expression following ischemic conditioning of the gastric conduit

The partial devascularization of the stomach, necessary for esophageal reconstruction with a gastric conduit, impairs microcirculation in the anastomotic region of the gastric fundus. Ischemic conditioning of the gastric tube is considered as a possible approach to improve microcirculation in the gastric mucosa. The aim of this study was to investigate whether ischemic conditioning induces neo-angiogenesis in the gastric fundus by expression of vascular endothelial growth factor (VEGF). Twenty patients with an esophageal carcinoma scheduled for esophagectomy and gastric reconstruction were included. To compare VEGF expression before and after ischemic conditioning, preoperative endoscopic biopsies were taken from the gastric fundus. The surgical procedure consisted of two separate steps, the complete gastric mobilization including partial devascularization of the stomach and after a delay of 4-5 days high transthoracic esophagectomy with intrathoracic gastric reconstruction (Ivor-Lewis procedure). The second tissue sample was obtained from the donut of the stapled esophagogastrostomy. For further work-up, preoperative biopsies and the gastric donuts were fixed in liquid nitrogen. Preoperative and intraoperative VEGF expression was measured by quantitative real-time reverse transcription-polymerase chain reaction (VEGF×100/β-actin) and results were compared using Wilcoxon test for paired samples. In all 40 specimens, a distinct expression of VEGF could be detected. Comparing the level of VEGF expression of the preoperative biopsies and postoperative tissue sample, no significant difference could be demonstrated following ischemic conditioning. In this model of ischemic conditioning with delayed reconstruction of 4-5 days, no induction of neo-angiogenesis could be demonstrated by measurement of VEGF expression.

Changes of smooth muscle contractile filaments in small bowel atresia

AIM: To investigate morphological changes of intestinal smooth muscle contractile fibres in small bowel atresia patients.

METHODS: Resected small bowel specimens from small bowel atresia patients (n = 12) were divided into three sections (proximal, atretic and distal). Standard histology hematoxylin-eosin staining and enzyme immunohistochemistry was performed to visualize smooth muscle contractile markers α-smooth muscle actin (SMA) and desmin using conventional paraffin sections of the proximal and distal bowel. Small bowel from age-matched patients (n = 2) undergoing Meckel’s diverticulum resection served as controls.

RESULTS: The smooth muscle coat in the proximal bowel of small bowel atresia patients was thickened compared with control tissue, but the distal bowel was unchanged. Expression of smooth muscle contractile fibres SMA and desmin within the proximal bowel was slightly reduced compared with the distal bowel and control tissue. There were no major differences in the architecture of the smooth muscle within the proximal bowel and the distal bowel. The proximal and distal bowel in small bowel atresia patients revealed only minimal differences regarding smooth muscle morphology and the presence of smooth muscle contractile filament markers.

CONCLUSION: Changes in smooth muscle contractile filaments do not appear to play a major role in postoperative motility disorders in small bowel atresia.

The prognostic impact of extracapsular lymph node involvement in rectal cancer patients: Implications for staging and adjuvant treatment strategies

Limited data suggest that extracapsular lymph node involvement (LNI) has a negative prognostic impact in gastrointestinal malignancies. The aim of this study was to assess the prevalence and prognostic impact of LNI in patients with primary resected rectal cancer. Between 1997 and 2007, 243 rectal cancer patients underwent surgical therapy without neoadjuvant treatment at our Department. Of these, 12 (5%) patients received transanal endoscopic microsurgery and were not included for further analyses. In the remaining patients, a (low) anterior resection was performed in 79% and an abdominoperineal rectal amputation in 21%. The total number of analyzed lymph nodes and the number of metastatic lymph nodes with/without extracapsular LNI were determined and the prognostic impact of LNI was assessed. The median number of analyzed lymph nodes was 14. In total, 59% of patients were node-negative, 18% of patients were node-positive without extracapsular LNI and 23% of patients were node-positive with extracapsular LNI. A positive lymph node status with extracapsular LNI was significantly correlated with a poorer T-, N- and M-category, grading and more frequent lymphatic vessel infiltration compared with node-negative or node-positive without extracapsular LNI patients (p<0.001). The overall 5-year survival rate of node-negative patients was 75%, for node-positive without extracapsular LNI patients 69% and for node-positive with extracapsular LNI patients 36% (p<0.001). By multivariate analysis, the N-category with extracapsular LNI was characterized as an independent prognostic factor. Extracapsular lymph node involvement reveals an independent negative prognostic impact in patients with rectal cancer undergoing surgical therapy. Staging systems for rectal cancer should include the implementation of extracapsular lymph node involvement.

Reduced oxygen stress promotes propagation of murine postnatal enteric neural progenitors in vitro

BACKGROUND

Neural stem and progenitor cells of the Enteric Nervous System (ENS) are regarded as a novel cell source for applications in regenerative medicine. However, improvements to the current ENS cell culture protocols will be necessary to generate clinically useful cell numbers under defined culture conditions. Beneficial effects of physiologically low oxygen concentrations and/or the addition of anti-oxidants on propagation of various types of stem cells have previously been demonstrated. In this study, we tested the effects of such culture conditions on ENS stem and progenitor cell behavior.

METHODS

Enteric neural progenitor cells were isolated from postnatal day 3 mouse intestine and propagated either as monolayers or neurosphere-like bodies. The influence of hypoxic culture conditions and/or anti-oxidants on enteric cell propagation were studied systematically using proliferation, differentiation and apoptosis assays, whereas effects on gene expression were determined by qRT-PCR, western blot, and immunocytochemistry.

KEY RESULTS

Both hypoxic culture conditions and anti-oxidants supported a significantly improved enteric cell propagation and the generation of differentiated neural cell types. Enteric neural progenitors were shown to be specifically vulnerable to persistent oxidative stress.

CONCLUSIONS & INFERENCES

Our findings are consistent with previous reports of improved maintenance of brain stem cells cultured under reduced oxygen stress conditions and may therefore be applied to future cell culture protocols in ENS stem cell research.

Embryology of the hindgut

Normal and abnormal development of the hindgut is still in debate. Normal development of the hindgut critically depends on the cloacal membrane. In this study, scanning electron microscopy of staged rat embryos between the gestational days 10-15 was performed to show the normal development of the hindgut and the abnormal development in Danforth's short tail (SD) mice. Our studies in normal and abnormal development indicate that the embryonic cloaca never passes through a stage that is similar to any form of anorectal malformation in neonates, including the so-called "cloacas" in females. To explain the abnormal development in anorectal malformations, further studies are mandatory.

The embryology of the diaphragm

Despite the progress in prenatal diagnosis and intervention as well as postnatal therapeutic strategies, congenital diaphragmatic hernia (CDH) is still associated with a meaningful mortality because of the induced pulmonary hypoplasia. An essential key in understanding the pathogenesis of CDH is the underlying embryology, which has been neglected during the last decades. Likewise, the development of the normal diaphragm is still poorly understood. Obsolescent perceptions, mainly formed from histologic sections, are still propagated. In this review we present an atlas of scanning electron microscopy images that depict the normal and defective development of the diaphragm in the nitrofen rat model for CDH. Our findings suggest that the normal diaphragm mainly develops from the posthepatic mesenchymal plate. If the development of the posthepatic mesenchymal plate is impaired, a diaphragmatic defect occurs.

Embryology of the distal urethra and external genitals

Faulty ventral openings of the urethra constitute a broad spectrum of malformations that are subsumed under the term "hypospadia." The normal development of the urethra and the genitals critically depends on the following events: (a) formation of the external genitalia, (b) fate of the cloacal membrane, and (c) formation of the distal urethra. The purpose of this study was to demonstrate these events using microsurgical techniques and scanning electron microscopy in staged rat embryos.

Embryology of the testicular descent

Numerous researchers studied the morphology of the testicular descent, including the possible function of the gubernaculum. However, a clear illustration of this process is still missing. The aim of this paper was to illustrate the embryology of the testicular descent in the rat by scanning electron microscopy. In a first phase of the intra-abdominal testicular descent, the testis moves actively from the lower pole of the kidney towards the bladder neck. In a second inguinal phase the testis enters groin and moves in the developing processus vaginalis peritonei caused by the disappearance of the bulb of the gubernaculums testis.

Embryology of the midgut

In most textbooks of embryology and pediatric surgery, the puzzling spectrum of midgut "malrotations" is explained by an "impaired" process of rotation of the midgut. However, this "process of rotation" is explained in a rather schematic way and aims more to explain pathologic findings whereas detailed embryologic investigations are still rare in this field. Good animal models which would allow the comparison of normal and abnormal midgut development are missing. In this paper we describe the development of the midgut in form of an atlas. Scanning electron microscopy is used in rat embryos to illustrate the crucial embryologic processes of midgut development. The main result shown in these illustrations is that clear signs of a process of rotation are missing.

Embryology of the early foregut

In embryology, no agreement exists how the early foregut differentiates into the respiratory tract and the intestinal tract. In particular, the formation of the early lung anlage as well as the process of separation of trachea and esophagus remains unclear. This process is explained in a rather schematic way and aims more to explain pathologic findings, whereas true embryologic investigations are extremely rare in this field. Here, scanning electron microscopy of the normal foregut development illustrates the steps, which finally leads to the development of larynx and trachea on the one hand, and pharynx and esophagus on the other hand. This study was performed in chicken embryos in accordance to the developmental stages described. As the main results from these illustrations show, we found no evidence for lateral foregut ridges inside the undivided foregut chamber and no fusion of lateral foregut components to form a trachea-esophageal septum.

[Cystic abdominal mass as a complication due to posterior urethral valves]

A case of urinoma with posterior urethral valves and its management is presented. Diagnostic investigations and therapy strategies are discussed. Though rare, this possibility should be considered in the differential diagnosis of neonates presenting with rapidly expanding cystic masses in the abdomen. Early diagnosis and management are the most important prognostic factors that ensure a good outcome in such cases.

Differential changes in intrinsic innervation and interstitial cells of Cajal in small bowel atresia in newborns

AIM

To investigate morphological changes of the enteric nervous system (ENS) and the interstitial cells of Cajal (ICCs) in small bowel atresia.

METHODS

Resected small bowel specimens from affected patients (n = 7) were divided into three parts (proximal, atretic, distal). Standard histology and enzyme immunohistochemistry anti-S100, anti-protein gene product (PGP) 9.5, anti-neurofilament (NF), anti-c-kit-receptor (CD117) was carried out on conventional paraffin sections of the proximal and distal part.

RESULTS

The neuronal and glial markers (PGP 9.5, NF, S-100) were expressed in hypertrophied ganglia and nerve fibres within the myenteric and submucosal plexuses. Furthermore, the submucous plexus contained typical giant ganglia. The innervation pattern of the proximal bowel resembled intestinal neuronal dysplasia. The density of myenteric ICCs was clearly reduced in the proximal bowel, whereas a moderate number of muscular ICCs were found. The anti-CD117 immunoreaction revealed additional numerous mast cells. The distal bowel demonstrated normal morphology and density of the ENS, the ICCs and the mast cells.

CONCLUSION

The proximal and distal bowel in small bowel atresia revealed clear changes in morphology and density of the ENS and ICCs.

Conformational fingerprinting of the angiotensin I-converting enzyme (ACE). 1. Application in sarcoidosis

Fine epitope mapping of monoclonal antibodies (mAbs) to 16 epitopes on human angiotensin I-converting enzyme (ACE) revealed that the epitopes of all mAbs contained putative glycosylation sites. ACE glycosylation is both cell- and tissue-specific and, therefore, the local conformation of ACE produced by different cells could be also unique. The pattern of ACE binding by a set of mAbs to 16 epitopes of human ACE - "conformational fingerprint of ACE" - is the most sensitive marker of ACE conformation and could be cell- and tissue-specific. The recognition of ACEs by mAbs to ACE was estimated using an immune-capture enzymatic plate precipitation assay. Precipitation patterns of soluble recombinant ACE released from Chinese hamster ovary (CHO)-ACE cells was influenced by conditions that alter ACE glycosylation. This pattern was also strongly cell type specific. Patients with sarcoidosis exhibited conformational fingerprints of tissue ACE (lungs and lymph nodes), as well as blood ACE, which were distinct from controls. Conformational fingerprinting of ACE may detect ACE originated from the cells other than endothelial cells in the blood and when combined with elevated blood ACE levels in patients with sarcoidosis may potentially reflect extrapulmonary sarcoidosis involvement (bone marrow, spleen, liver). If proven true, this would serve as a biomarker of enormous potential clinical significance.

Residual lymph node metastasis in stage 4 neuroblastoma--advantage of radio-guided surgery?

Log-term prognosis of children suffering from high-risk neuroblastomas is characterized by a shortened event-free survival, especially if metastases remain after chemotherapy. We report the case of a 3-year-old boy afflicted with a stage 4 neuroblastoma and persistent residual lymph node metastases despite the administration of a various number of treatment modalities. The insertion of a MIBG (metaiodobenzylguanidine) single-photon emission computed tomography (SPECT)-CT and radio-guided surgery implementing a hand held gamma probe finally allowed the exact localization and resection of the suspected lymphatic tissue. As a consequence, the child has been under event-free remission for 20 months. Because study-based knowledge is missing due to the small number of affected patients, individual case reports are helpful to improve future treatment strategies.

[18F]-fluorodeoxyglucose-positron emission tomography for the assessment of histopathologic response and prognosis after completion of neoadjuvant chemotherapy in gastric cancer

BACKGROUND AND OBJECTIVES

Neoadjuvant chemotherapy is applied to improve the prognosis of patients with advanced gastric cancer. However, only a major histopathological response will provide a benefit. Recent studies suggest that [(18)F]-fluorodeoxyglucose-positron-emission-tomography (FDG-PET) correlates with response and survival in patients with gastroesophageal adenocarcinomas undergoing neoadjuvant chemotherapy. We evaluated the potential of FDG-PET for the assessment of response and prognosis in the multimodality treatment of gastric cancer.

METHODS

Study patients were recruited from a prospective observation trial. Forty two patients with advanced gastric cancer received neoadjuvant chemotherapy and subsequently 40 patients underwent standardized gastrectomy (2 patients with tumor progression had therapy limited to palliative chemotherapy without surgery). Histomorphologic regression was defined as major response when resected specimens contained <10% vital tumor cells. FDG-PET was performed before and 2 weeks after the end of neoadjuvant chemotherapy with assessment of the intratumoral FDG-uptake [pre-treatment standardized uptake value (SUV1); post-treatment SUV (SUV2); percentage change (SUVDelta%)].

RESULTS

Histomorphological tumor regression was confirmed as a prognostic factor (P = 0.039). No significant correlations between SUV1, SUV2, or SUVDelta% and response or prognosis were found.

CONCLUSION

FDG-PET seems not to be an imaging system that effectively characterizes major/minor response and survival in patients with gastric cancer following multimodality treatment.

The testicular descent in the rat: a scanning electron microscopic study

PURPOSE

Numerous researchers studied the morphology of testicular descent including the possible function of gubernaculum. However, a clear illustration of this process is still missing. The aim of this study was to illustrate testicular descent using scanning electron microscopy (SEM) in a rat model.

METHODS

The abdomen of rat fetuses between gestational day (E) 15 and E 22 and newborns at postnatal day (D) 0 and D 1.5 was opened by microsurgery. Standard preparation for SEM was carried out. The position of the testis and gubernaculum testis was documented.

RESULTS

The gubernaculum was obvious in male rat embryos at E 17.5. In a first phase (E 16-E 21) the testis moved from cranio-lateral and dorsal to caudo-medial and ventral, while clear signs of an active role of the gubernaculum were missing. In a second phase (E 22-D 1.5) the processus vaginalis peritonei (PVP) developed, while the conus of the gubernaculum disappeared, after which, the testis moved out of the abdominal cavity and entered the PVP.

CONCLUSION

In our study, we could not specify the role of gubernaculum for testicular descent. However, our data showed that the testis lay intraperitoneal throughout the descensus testis.

Reduced expression of angiotensin I-converting enzyme in caveolin-1 knockout mouse lungs

Reduced lung capillary expression of angiotensin I-converting enzyme (ACE), a key enzyme in cardiovascular pathophysiology, and of caveolin-1, an important regulator of endothelial cell signalling, has been demonstrated in various models of pulmonary arterial hypertension (PAH). We addressed the relationship between PAH and ACE expression in caveolin-1 knockout mice (Cav1(-/-)), which have moderate PAH. Tissue ACE activity was reduced by 50% in lungs from 3-month-old Cav1(-/-) mice compared to wild type (WT). A similar reduction in lung endothelial ACE expression was observed by measuring the lung uptake of (125)I-labeled monoclonal anti-ACE antibody and by quantitative immunohistochemistry. These alterations in ACE are limited to capillary segments of the pulmonary circulation. Functionally, the increase in pulmonary artery pressure (PAP) in response to ACE conversion of angiotensin I to angiotensin II in isolated, perfused mouse lungs was reduced significantly in Cav1(-/-) mice compared to WT. Thus, these complementary approaches demonstrate the dependence of lung microvascular endothelial cell ACE protein expression on caveolin-1 expression and underscore the vital role of caveolin-1-regulated pulmonary vascular homeostasis on endothelial ACE expression and activity. In summary, we have revealed a novel role of caveolin-1 in the regulation of ACE expression in pulmonary capillary endothelial cells. Further understanding of the mechanism by which reduced caveolin-1 expression leads altered pulmonary vascular development, PAH, and reduced ACE expression may have important clinical implications in patients with these severe lung diseases.

Y-box-binding protein-1 is a potential novel tumour marker for neuroblastoma

BACKGROUND

The Y-box-binding protein-1 (YB-1) is a member of a family of DNA-binding proteins and an oncogenic transcription factor that is highly expressed in cancers of the breast, lung and prostate. To date, no data are available on its role in neuroblastoma. The aim of the present study was to evaluate the YB-1 expression in neuroblastoma.

MATERIALS AND METHODS

A tumour tissue microarray (TMA) was constructed from 36 neuroblastoma samples which were analysed by immunohistochemistry for YB-1 expression.

RESULTS

Expression of YB-1 was detected in 35 of 37 (94.6%) neuroblastoma cases examined. Nevertheless, no correlation of YB-1 expression with survival, risk factors or stage of the disease was observed.

CONCLUSION

As the majority of neuroblastomas express YB-1, this protein may play an important role in tumour pathogenesis. The results of this study suggest that YB-1 may serve as a novel immune marker for neuroblastoma and may be potentially useful as a therapeutic target.

Foetal hepatocyte transplantation in a vascularized AV-Loop transplantation model in the rat

The use of foetal liver cells (FLC) in the context of hepatic tissue engineering might permit efficient in vitro expansion and cryopreservation in a cell bank. A prerequisite for successful application of bioartificial liver tissue is sufficient initial vascularization. In this study, we evaluated the transplantation of fibrin gel-immobilized FLC in a vascularized arterio-veno-venous (AV)-loop model. FLC were isolated from embryonic/foetal (ED 16) rat livers and were enriched by using magnetic cell sorting (MACS). After cryopreservation, FLC were labelled by pkh-26. Cells were transplanted in a fibrin matrix into a subcutaneous chamber containing a microsurgically created AV-loop in the femoral region of the recipient rat. The chambers were explanted after 14 days. Subcutaneous implants without an AV-loop and cell-free implants served as controls. Fluorescence microscopy of the constructs was used to identify pkh-26(+)- donor cells. Characterization was performed by RT-PCR and immunhistology (IH) for CK-18 and CD31. Transplantation of FLC using the AV-loop permitted a neo-tissue formation in the fibrin matrix. A high-density vascularization was observed in the AV-loop constructs as shown by CD31 IH. Viable foetal donor cells were detected which expressed CK-18. FLC can be successfully used for heterotopic transplantation. Fibrin matrix permits rapid blood vessel ingrowth from the AV-loop and supports engraftment of FLC. It is therefore an appropriate environment for hepatocyte transplantation in combination with microsurgical vascularization strategies. Transplantation of fibrin gel-immobilized FLC may be a promising approach for the development of highly vascularized in vivo tissue-engineering-based liver support systems.

[Thoracic surgery in neonates and infants with congenital malformations]

Congenital malformations of the lung and diaphragm are a challenge in paediatric surgery. Depending on the malformation they show a broad spectrum of symptoms and a varying age at manifestation. Thus there are many diagnostic and therapeutic options, which require a good knowledge of the pathology. The treatment of these complex cases should lead to early referral to paediatric centres containing an interdisciplinary team with neonatologists, paediatric pulmonologists and cardiologists, ENT surgeons, anaesthesiologists, radiologists and paediatric surgeons. Some malformations are diagnosed prenatally and need intrauterine interventions. Decisive is the early diagnosis and treatment of these malformations. Nowadays the surgical therapy of neonates and infants with malformations of the lung and diaphragm is enriched by a number of endoscopic and endoluminal techniques, which are discussed critically in this article.

Development of hepatic tissue engineering

Liver transplantation is still the only treatment for end-staged liver diseases in children. However, donor organ shortage and immunosuppression are major limitations. Thus, approaches of hepatocyte transplantation are under investigation. Using cells might permit mass expansion, cryopreservation, and the ex vivo genetic modification of cells. For the development of cell-transplantation techniques, the use of three-dimensional scaffolds as carrier was shown to be advantageous. Polymeric matrices permit the formation of a neo-tissue and stimulation by the modification of the matrix surface. Another important issue is to define the right cell type for transplantation. Adult hepatocytes have a limited growth and differentiation potential. In contrast, fetal liver cells (FLC) possess an enormous growth and a bipotential differentiation potential. Thus, these cells may be very attractive as a cell resource for developing cell-based liver replacement. A third major issue in this approach is the neo-vascularization. Therefore, the transplantation in a recently developed model using a microsurgically created arterioveno-venous (AV) loop as a central vessel for the neo-tissue was used for transplantation of FLC in a fibrin-matrix. Initial results indicated that the transplantation of FLC using the AV-loop transplantation model may be promising for the development of highly vascularized in vivo tissue-engineered liver support systems.

Survivin expression in gastric cancer: Association with histomorphological response to neoadjuvant therapy and prognosis

BACKGROUND AND OBJECTIVES

Neoadjuvant therapy is applied to improve the prognosis associated with advanced gastric cancer. Only patients with a major response seem to have a survival benefit. Predictive markers to allow individualisation of treatment could be helpful. We examined the association of survivin protein expression with histopathologic response to neoadjuvant chemotherapy and prognosis in patients with gastric cancer.

METHODS

Forty patients with gastric cancer received neoadjuvant chemotherapy. Afterwards, 38 patients underwent total gastrectomy, while 2 patients received definitive chemotherapy because of tumour progression. Histomorphologic regression was defined as major response when resected specimens contained <10% tumour cells. Intratumoural survivin expression was determined by immunohistochemistry in pre- and post-therapeutic specimens and correlated with clinicopathologic parameters.

RESULTS

The pre- and post-therapeutic intratumoural survivin protein expression was not associated with histomorphologic regression. Post-therapeutic survivin expression did not have prognostic impact. A significant association was detected between pre-therapeutic survivin levels and prognosis: patients with a higher survivin protein expression showed a significant survival benefit. In multivariate analysis pre-therapeutic survivin expression was characterised as an independent prognostic marker, besides pN-status and histopathologic regression.

CONCLUSIONS

The pre-therapeutic survivin protein expression seems to be an independent prognostic marker in the multimodality treatment of advanced gastric cancer.

Evaluation of response in the multimodality treatment of esophageal cancer by [18F]-fluorodeoxyglucose-positron emission tomography: A systematic review and meta-analysis

e15520

Background: Neoadjuvant therapy followed by surgery is frequently applied to improve the prognosis of patients with esophageal cancer. However, only a major histopathological response will provide a survival benefit. On the other hand, evidence suggests that patients with response to chemoradiation have no additional benefit from surgery compared with definitive chemoradiation. Consequently, effective methods for early and late response assessment are required in order to perform these different individualised, response-guided treatment concepts. The value of [18F]-fluorodeoxyglucose-positron emission tomography (FDG-PET) for this diagnostic purpose is still under debate. This systematic review and meta-analysis aims to evaluate the potential of FDG-PETfor the assessment of response in the multimodality treatment of patients with esophageal cancer. Methods: A systematic literature search of studies published between 1990 and September 2008 was performed. The meta-analysis estimated the pooled sensitivity and specificity of histopathological response assessment by FDG-PET using a random effect model. Results: Thirty relevant studies with 1151 patients (865 adenocarcinoma, 493 squamous cell cancer) were identified and included in the systematic review. Mainly neoadjuvant chemoradiation (22 studies) was performed. FDG-PET was conducted mostly before and after neoadjuvant therapy (21 studies) and second most (6 studies) the subsequent FDG-PET was scheduled 7–14 days after the initiation of preoperative therapy. Sixteen studies were included in the meta-analysis. For metabolic response assessment 7–14 days after the initiation of therapy, including 254 patients (with 5 studies from one center), the pooled sensitivity was 85.5% (95% CI: 75.5%-92.8%) and specificity 76.1% (95% CI: 69.3%-82.0%). For late response assessment, including 446 patients, the pooled sensitivity was 77.1% (95% CI: 72.8%- 81.0%) and specificity 59.0% (95% CI: 55.3%-62.7%). Conclusions: For early response assessment FDP-PET seems to be useful in the multimodality treatment of esophageal cancer. In contrast, this study suggests FDG-PET invaluable for late response assessment.

No significant financial relationships to disclose.

GNAS1 T393C polymorphism is associated with histopathological response to neoadjuvant radiochemotherapy in esophageal cancer

Recent studies have shown an association between the GNAS1 T393C polymorphism and clinical outcome for various solid tumors. In this study, we genotyped 51 patients from an observational trial on cisplatin/5-FU-based neoadjuvant radiochemotherapy of locally advanced esophageal cancer (cT2-4, Nx, M0) and genotyping was correlated with histomorphological tumor regression. The C-allele frequency in esophageal cancer patients was 0.49. Pearson's chi(2)-test showed a significant (P<0.05) association between tumor regression grades and T393C genotypes. Overall, 63% of the patients in the T-allele group (TT+CT) were minor responders with more than 10% residual vital tumor cells in resection specimens, whereas T(-) genotypes (CC) showed a major histopathological response with less than 10% residual vital tumor cells in 80%. The results support the role of the T393C polymorphism as a predictive molecular marker for tumor response to cisplatin/5-FU-based radiochemotherapy in esophageal cancer.

Midkine is highly expressed in neuroblastoma tissues

PURPOSE

Neuroblastoma (NBL) is a tumor from neural crest cells, and is the most frequent solid tumor in children. Midkine (MK) is a pleiotropin analogon, which is frequently expressed in neuronal and epithelial tumors and is a marker for a poor clinical outcome. The aims of this study were to assess MK expression in NBL and investigate the correlation with clinical outcome.

METHODS

Fifty-six specimens of NBL were stained for MK on a tissue microarray by immunohistochemistry (IHC). Fresh frozen tumor tissues were used for RNA isolation, and RT-PCR analysis for MK-mRNA expression was performed. Survival data, risk factors and disease stages were correlated with MK status assessed by IHC and RT-PCR analysis.

RESULTS

MK-mRNA expression was found in the majority of the tumor tissues (75%), whereas MK protein could be detected only in 46% of the NBL by IHC. No correlation of MK status with survival, risk factors or disease stage was observed.

CONCLUSION

A majority of NBL express MK-mRNA, whereas not all MK mRNA positive tumors showed also a positive MK IHC staining. The high expression of MK-mRNA expression might present a promising target for new adenovirus-based gene therapeutic approaches for the treatment of NBL.

In vitro and in vivo evaluation of photodynamic techniques for the experimental treatment of human hepatoblastoma and neuroblastoma: preliminary results

PURPOSE

The purpose of this study was to test the susceptibility of human hepatoblastoma and neuroblastoma cells to photodynamic diagnostics (PDD) and photodynamic therapy (PDT) using 5-aminolevulinic acid (5-ALA) as a photosensitizer.

METHODS

Cell cultures of human hepatoblastoma (HuH6) and neuroblastoma (MHH-NB-11) were incubated with 5-ALA at increasing concentrations to measure the cellular kinetics of photosensitization. After optimizing incubation parameters, the cell cultures were then irradiated with increasing light doses and cell viability was measured by CTB assay. Human fibroblastic cells served as controls. So far, only the hepatoblastoma cell line has been tested in vivo. After injection of HUH6 cells in immunoincompetent rats, the efficacy of PDT was assessed. Photosensitization was achieved by intraperitoneal injection of 5-ALA. The pharmacokinetics of different tissues was studied. In a second study, a PDT of implanted hepatoblastoma, liver and peritoneum was performed. The irradiated areas were excised 48 h after treatment and studied by microscopy.

RESULTS

Cell culture experiments demonstrated a selective fluorescence for both tumor lines compared to controls. The photosensitized tumor cells demonstrated marked reductions in cell viability at significantly lower irradiation doses than the fibroblasts under PDT. The specificity of fluorescence was confirmed in vivo for hepatoblastoma, and all the sensitized and irradiated tumors showed marked phototoxic necrosis.

CONCLUSION

Human hepatoblastoma and neuroblastoma demonstrate marked and specific fluorescence after the application of 5-ALA, making PDD possible. Cell death occurred in both cell lines after PDT in vitro. Additionally, hepatoblastoma was susceptible to PDT in an animal model. Further studies will be necessary to determine the role of PDT and PDD in a clinical setting.

Universal expression of cell adhesion molecule NCAM in neuroblastoma in contrast to L1: implications for different roles in tumor biology of neuroblastoma?

PURPOSE

Neuroblastoma is a biological, genetic and morphological heterogeneous tumor with a variable clinical course. NCAM is a cell adhesion molecule belonging to the immunoglobulin superfamily with structural similarities to cell adhesion molecule L1. The aim of this study was to determine the expression of NCAM in neuroblastoma and to compare the results to the findings of a previous study which examined L1 expression in the same group of patients.

MATERIALS AND METHODS

NCAM expression was investigated on a tissue array with 66 surgically resected neuroblastoma samples by immunohistochemistry with a monoclonal antibody clone 1B6 and peroxidase method.

RESULTS

Strong expression of NCAM was detected in all of the 66 (100%) neuroblastoma tumors in contrast to L1 which was not expressed in all tumors.

CONCLUSION

In contrast to L1, which was found to predict favorable outcome, NCAM is universally expressed in neuroblastoma. Therefore NCAM represents a marker for neuroblastomas irrespectively of their stages whereas L1 as an indicator for developing neuronal cells seems to identify more mature stages of this tumor. The high grade of NCAM expression might present a prerequisite for establishment of antibody-based therapies.

Successful management of esophageal perforation due to an aortic arch aneurysm replacement

We present the successful management of an esophageal perforation after aortic arch aneurysm replacement in a 64-year-old patient. Four weeks after surgical repair of a perforated aortic arch aneurysm, a contained perforation of the thoracic esophagus on the prosthesis was detected. A subtotal esophagectomy and reconstruction by pull-up of the stomach together with the greater omentum and high intrathoracic esophagogastrostomy was performed. The aortic prosthesis was covered by omentum. After a prolonged postoperative course, the patient was discharged from the hospital on a full oral diet. She is well after 1 year without signs of infection.

Histological type of esophageal cancer might affect response to neo-adjuvant radiochemotherapy and subsequent prognosis

BACKGROUND

This study investigates response and prognosis after neo-adjuvant chemoradiation (CTx/RTx) in patients with advanced esophageal carcinoma, according to histological type.

PATIENTS AND METHODS

Patients with uT3 carcinoma of the esophagus treated with curative-intention esophagectomy from 1997 until 2006 were included in this retrospective analysis. Patients receiving preoperative CTx/RTx (5-fluorouracil, cisplatin, 36 Gy) were compared with those with primary surgery for pT3 tumors. Therapy response after CTx/RTx was evaluated using 'Cologne Regression Grade' (minor response: >or=10% vital residual tumor cells (VRTCs), major response: <10% VRTC or pathologic complete response). Prognosis was evaluated for adenocarcinoma (AC) and squamous cell carcinoma (SCC).

RESULTS

Of 297 patients, 52% were SCC and 48% AC. In all, 192 patients underwent CTx/RTx, 100 (65%) SCC and 92 (64%) AC (nonsignificant). In SCC group 51% and in AC group 29% achieved major response (P < 0.01). Patients with major response had a 2-year survival rate (2y-SR) of 78% versus those with minor response or without CTx/RTx, with a 2y-SR of 45% (P = 0.001). Examining patients with major response exclusively, the prognosis of AC (2y-SR 85%) is better than that of SCC (2y-SR 54%) (P < 0.01).

CONCLUSION

This retrospective study concludes that in esophageal tumors, response to and prognosis after neo-adjuvant CTx/RTx vary according to histology.