Exploring Monological and Dialogical Phases in Naturally Occurring Explanations

Recent approaches to Explainable AI (XAI) promise to satisfy diverse user expectations by allowing them to steer the interaction in order to elicit content relevant to them. However, little is known about how and to what extent the explainee takes part actively in the process of explaining. To tackle this empirical gap, we exploratively examined naturally occurring everyday explanations in doctor–patient interactions (N = 11). Following the social design of XAI, we view explanations as emerging in interactions: first, we identified the verbal behavior of both the explainer and the explainee in the sequential context, which we could assign to phases that were either monological or dialogical; second, we investigated in particular who was responsible for the initiation of the different phases. Finally, we took a closer look at the global conversational structure of explanations by applying a context-sensitive model of organizational jobs, thus adding a third layer of analysis. Results show that in our small sample of conversational explanations, both monological and dialogical phases varied in their length, timing of occurrence (at the early or later stages of the interaction) and their initiation (by the explainer or the explainee). They alternated several times in the course of the interaction. However, we also found some patterns suggesting that all interactions started with a monological phase initiated by the explainer. Both conversational partners contributed to the core organizational job that constitutes an explanation. We interpret the results as an indication for naturally occurring everyday explanations in doctor–patient interactions to be co-constructed on three levels of linguistic description: (1) by switching back and forth between monological to dialogical phases that (2) can be initiated by both partners and (3) by the mutual accomplishment and thus responsibility for an explanation’s core job that is crucial for the success of the explanation. Because of the explorative nature of our study, these results need to be investigated (a) with a larger sample and (b) in other contexts. However, our results suggest that future designs of artificial explainable systems should design the explanatory dialogue in such a way that it includes monological and dialogical phases that can be initiated not only by the explainer but also by the explainee, as both contribute to the core job of explicating procedural, clausal, or conceptual relations in explanations.

Operative Volume of Newborn Surgery in German University Hospitals: High Volume Versus Low Volume Centers

INTRODUCTION

 Adequate patient volume is essential for the maintenance of quality, meaningful research, and training of the next generation of pediatric surgeons. The role of university hospitals is to fulfill these tasks at the highest possible level. Due to decentralization of pediatric surgical care during the last decades, there is a trend toward reduction of operative caseloads. The aim of this study was to assess the operative volume of the most relevant congenital malformations at German academic pediatric surgical institutions over the past years.

METHODS

 Nineteen chairpersons representing university-chairs in pediatric surgery in Germany submitted data on 10 index procedures regarding congenital malformations or neonatal abdominal emergencies over a 3-year period (2015 through 2017). All institutions were categorized according to the total number of respective cases into "high," "medium," and "low" volume centers by terciles. Some operative numbers were verified using data from health insurance companies, when available. Finally, the ratio of cumulative case load versus prevalence of the particular malformation was calculated for the study period.

RESULTS

 From 2015 through 2017, a total 2,162 newborns underwent surgery for congenital malformations and neonatal abdominal emergencies at German academic medical centers, representing 51% of all expected newborn cases nationwide. The median of cases per center within the study period was 101 (range 18-258). Four institutions (21%) were classified as "high volume" centers, four (21%) as "medium volume" centers, and 11 (58%) as "low volume" centers. The proportion of patients operated on in high-volume centers varied per disease category: esophageal atresia/tracheoesophageal fistula: 40%, duodenal atresia: 40%, small and large bowel atresia: 39%, anorectal malformations: 40%, congenital diaphragmatic hernia: 56%, gastroschisis: 39%, omphalocele: 41%, Hirschsprung disease: 45%, posterior urethral valves: 39%, and necrotizing enterocolitis (NEC)/focal intestinal perforation (FIP)/gastric perforation (GP): 45%.

CONCLUSION

 This study provides a national benchmark for neonatal surgery performed in German university hospitals. The rarity of these cases highlights the difficulties for individual pediatric surgeons to gain adequate clinical and surgical experience and research capabilities. Therefore, a discussion on the centralization of care for these rare entities is necessary.

Decision-Making in the Pediatric Emergency Department-A Survey of Guidance Strategies among Residents

(1) Introduction: Working in an emergency department requires fast and straightforward decisions. Therefore, decision guidance represents an essential tool for successful patient-centered care. Beyond the residents' own knowledge and experience, printed books have been the primary source of information in the past. The aim of this study was to discover which strategies current residents use the most and to identify alternative quick reference strategies in the digital age. (2) Materials and Methods: This study analyzed the responses of a short questionnaire directed at 41 residents in a single pediatric emergency department (32 pediatric and 9 pediatric surgery residents) over a period of one month. (3) Results: Thirty-three (80.5%) residents answered the entire questionnaire. Strikingly, responses indicated that printed books are still pivotal in guiding decision-making. In addition, the acquisition of information via computers or smartphones plays an increasing role. However, the opinion and council of the attending physician is still of great value to the residents and is not to be underestimated. Overall, most of the residents would prefer to have access to a specially designed smartphone application. (4) Conclusions: Certainty and validity are essential in decision-making in a pediatric emergency department. Although printed books and attending physicians are still considered as reliable sources of information, internet-based information plays an increasing role. In order to provide the best up-to-date and most recent information, a validated and consistently updated smartphone application could be a useful option.

Correlation of PET-MRI, pathology, LOH and surgical success in a case of CHI with atypical large pancreatic focus

Congenital hyperinsulinism (CHI) is a rare cause of severe hypoglycemia in newborns. In focal CHI, usually one activity peak in fluorine-18-L-dihydroxyphenylalanine (¹⁸F-DOPA) positron emission tomography–magnetic resonance imaging (PET-MRI) indicates one focal lesion and its resection results in cure of the child. We present the case of a 5-month-old girl with CHI. Mutational screening of genes involved in CHI revealed a heterozygous pathogenic variant in the ABCC8 gene, which was not detectable in the parents. ¹⁸F-DOPA PET-MRI revealed 2 distinct activity peaks nearby in the pancreatic body and neck. Surgical resection of the tissue areas representing both activity peaks resulted in long-lasting normoglycemia that was proven by a fasting test. Molecular analysis of tissue samples from various sites provided evidence that a single second genetic hit in a pancreatic precursor cell was responsible for the atypical extended pancreatic lesion. There was a close correlation in the resected areas of PET-MRI activity with focal histopathology and frequency of the mutant allele (loss of heterozygosity) in the tissue. Focal lesions can be very heterogenous. The resection of the most affected areas as indicated by imaging, histopathology, and genetics could result in complete cure.

Integration of genomic analysis and transcript expression of ABCC8 and KCNJ11 in focal form of congenital hyperinsulinism

BACKGROUND

The focal form of CHI is caused by an autosomal recessive pathogenic variant affecting the paternal homologue of genes ABCC8 or KCNJ11 and a second somatic event specifically occurring in the affected islet of Langerhans. The approach of this study was to integrate the genetic changes occurring in pancreatic focal lesions of CHI at the genomic and transcriptional level.

RESEARCH DESIGN AND METHODS

Patients receiving therapeutic surgery and with proven ABCC8 or KCNJ11 pathogenic variants were selected and analyzed for loss of heterozygosity (LOH), changes in copy number and uniparental disomy (UPD) on the short am of chromosome 11 by molecular microarray analysis and methylation-specific MLPA. Gene expression was analyzed by RT-PCR and Massive Analysis of cDNA Ends (MACE).

RESULTS

Both genes, ABCC8 and KCNJ11, are located in proximity to the Beckwith-Wiedemann (BWS) imprinting control region on chromosome 11p15. Somatic paternal uniparental isodisomy (UPD) at chromosome 11p was identified as second genetic event in focal lesions resulting in LOH and monoallelic expression of the mutated ABCC8/KCNJ11 alleles. Of five patients with samples available for microarray analysis, the breakpoints of UPD on chromosome 11p were different. Samples of two patients were analyzed further for changes in gene expression. Profound downregulation of growth suppressing genes CDKN1 and H19 was detected in focal lesions whereas growth promoting gene ASCL2 and pancreatic transcription factors of the endocrine cell lineage were upregulated.

CONCLUSIONS

Paternal UPD on the short arm of chromosome 11 appears to be the major second genetic event specifically within focal lesions of CHI but no common breakpoint for UDP can be delineated. We show for the first time upregulation of growth promoting ASCL2 (achaete-scute homolog 2) suggestive of a driving factor in postnatal focal expansion in addition to downregulation of growth suppressing genes CDKN1C and H19.

Pasireotide treatment for severe congenital hyperinsulinism due to a homozygous ABCC8 mutation

ABCC8 and KCJN11 mutations cause the most severe diazoxide-resistant forms of congenital hyperinsulinism (CHI). Somatostatin analogues are considered as secondline treatment in diazoxide-unresponsive cases. Current treatment protocols include the first-generation somatostatin analogue octreotide, although pasireotide, a second-generation somatostatin analogue, might be more effective in reducing insulin secretion. Herein we report the first off-label use of pasireotide in a boy with a severe therapy-resistant form of CHI due to a homozygous ABCC8 mutation. After partial pancreatectomy, hyperinsulinism persisted; in an attempt to prevent further surgery, off-label treatment with pasireotide was initiated. Short-acting pasireotide treatment caused high blood glucose level shortly after injection. Long-acting pasireotide treatment resulted in more stable glycemic control. No side effects (e.g., central adrenal insufficiency) were noticed during a 2-month treatment period. Because of recurrent hypoglycemia despite a rather high carbohydrate intake, the boy underwent near-total pancreatectomy at the age of 11 months. In conclusion, pasireotide treatment slightly improved glycemic control without side effects in a boy with severe CHI. However, the effect of pasireotide was not sufficient to prevent near-total pancreatectomy in this case of severe CHI.

Technical aspects of paediatric robotic pancreatic enucleation based on a case of an insulinoma

BACKGROUND

Insulinomas are rare insulin-producing pancreatic neuroendocrine tumours leading to severe episodes of hypoglycaemia. Surgery is the predominant curative therapy.

METHODS

We report here the first paediatric case of an insulinoma of the pancreatic body resected completely robotically under ultrasound guidance in a 10-year-old male with multiple endocrine neoplasia type 1. The port set-up was adapted for the narrowed dimensions of the paediatric peritoneal space. We comment on technical key steps for the organ-preserving procedure that was performed in close proximity to critical anatomic structures, with supporting video. Preoperative diagnostics, including endoscopic ultrasound, to determine surgical management are highlighted.

RESULTS

Following an uneventful post-operative course, the boy was discharged on day 11 with normalised glucose-metabolism. A pseudocyst developing after 4 weeks was treated with endoscopic stenting.

CONCLUSIONS

The applicability of a robotic surgical system in limited space conditions such as found in the paediatric abdominal cavity is demonstrated here for pancreatic surgery.

Possible New Strategies for the Treatment of Congenital Hyperinsulinism

OBJECTIVE

Congenital hyperinsulinism (CHI) is a rare disease characterized by persistent hypoglycemia as a result of inappropriate insulin secretion, which can lead to irreversible neurological defects in infants. Poor efficacy and strong adverse effects of the current medications impede successful treatment. The aim of the study was to investigate new approaches to silence β-cells and thus attenuate insulin secretion.

RESEARCH DESIGN AND METHODS

In the scope of our research, we tested substances more selective and more potent than the gold standard diazoxide that also interact with neuroendocrine ATP-sensitive K⁺ (K_ATP) channels. Additionally, K_ATP channel-independent targets as Ca²⁺-activated K⁺ channels of intermediate conductance (K_Ca3.1) and L-type Ca²⁺ channels were investigated. Experiments were performed using human islet cell clusters isolated from tissue of CHI patients (histologically classified as pathological) and islet cell clusters obtained from C57BL/6N (WT) or SUR1 knockout (SUR1^-/-) mice. The cytosolic Ca²⁺ concentration ([Ca²⁺]_c) was used as a parameter for the pathway regulated by electrical activity and was determined by fura-2 fluorescence. The mitochondrial membrane potential (ΔΨ) was determined by rhodamine 123 fluorescence and single channel currents were measured by the patch-clamp technique.

RESULTS

The selective K_ATP channel opener NN414 (5 µM) diminished [Ca²⁺]_c in isolated human CHI islet cell clusters and WT mouse islet cell clusters stimulated with 10 mM glucose. In islet cell clusters lacking functional K_ATP channels (SUR1^-/-) the drug was without effect. VU0071063 (30 µM), another K_ATP channel opener considered to be selective, lowered [Ca²⁺]_c in human CHI islet cell clusters. The compound was also effective in islet cell clusters from SUR1^-/- mice, showing that [Ca²⁺]_c is influenced by additional effects besides K_ATP channels. Contrasting to NN414, the drug depolarized ΔΨ in murine islet cell clusters pointing to severe interference with mitochondrial metabolism. An opener of K_Ca3.1 channels, DCEBIO (100 µM), significantly decreased [Ca²⁺]_c in SUR1^-/- and human CHI islet cell clusters. To target L-type Ca²⁺ channels we tested two already approved drugs, dextromethorphan (DXM) and simvastatin. DXM (100 µM) efficiently diminished [Ca²⁺]_c in stimulated human CHI islet cell clusters as well as in stimulated SUR1^-/- islet cell clusters. Similar effects on [Ca²⁺]_c were observed in experiments with simvastatin (7.2 µM).

CONCLUSIONS

NN414 seems to provide a good alternative to the currently used K_ATP channel opener diazoxide. Targeting K_Ca3.1 channels by channel openers or L-type Ca²⁺ channels by DXM or simvastatin might be valuable approaches for treatment of CHI caused by mutations of K_ATP channels not sensitive to K_ATP channel openers.

Management of tumor rupture and abdominal compartment syndrome in an infant with bilateral high risk stage 4 neuroblastoma: A case report

RATIONALE

Tumor rupture and bleeding at initial presentation of infants with neuroblastoma (NBL) is a rare, but life threatening condition and challenge in pediatric oncology. Here, we report successful multidisciplinary management of an abdominal compartment syndrome as a result of tumor rupture and bleeding in an infant with bilateral high risk stage 4 NBL.

PATIENT CONCERNS

The patient was admitted to a cooperating hospital with vomiting, failure to thrive and a large mass in the abdomen and was then referred to our center.

DIAGNOSES

Stage 4 NBL with MYC-N amplification and 1p36 deletion was diagnosed in an 11 months old girl. Due to rapid and massive tumor growth she developed abdominal compression with renal failure, severe bleeding, and tumor lysis syndrome (TLS).

INTERVENTIONS

Surgical decompression by enterostomy, local, and systemic bleeding control with platelets and coagulation factors, antiinfective and TLS therapy were effective in stabilizing the patient's condition. This allowed initiation of the multimodal antineoplastic treatment according to protocol NB 2004.

OUTCOMES

Mechanical ventilation was stopped after 11 days, the abdominal wall was closed 3 months after the start of therapy, and treatment according to the protocol be started and successfully completed.

LESSONS

Only the immediate, coordinated multidisciplinary intervention managed to overcome the life-threatening abdominal compartment syndrome and its associated problems, eventually enabling successful curative treatment.

Surgery in Focal Congenital Hyperinsulinism (CHI) - The "Hyperinsulinism Germany International" Experience in 30 Children

OBJECTIVES

Results of surgery for focal CHI in 30 children PATIENTS AND METHODS: All showed an ABCC8 or KCNJ11 mutation. After PET/CT in 29 children and PET/MRT in 1 case, frozen-section guided resection was performed, in left-sided cases by laparoscopy. Mean age at surgery was 11.7 months (2-49).

RESULTS

In 28/30 children, the PET/CT or MRT correlated with histopathology. In two cases, a focal lesion was undectable; one of these was cured, one not. In total, 24 children showed lesions with sizes of 5-12 mm. All were cured instantly. In four children with huge lesions in the pancreatic head, pathological cells remained at the resection margins. One child was cured instantly, two children after a 2nd surgery, and one child was not cured, even after three surgeries. The overall cure rate was 93%.

CONCLUSIONS

Imaging, surgical findings, histopathology and clinical outcome in surgery for focal CHI match in most, but not all cases.

Tolerability, response and outcome of high-risk neuroblastoma patients treated with long-term infusion of anti-GD2 antibody ch14.18/CHO

Immunotherapy with short term infusion (STI) of monoclonal anti-GD₂ antibody (mAb) ch14.18 (4 × 25 mg/m²/d; 8-20 h) in combination with cytokines and 13-cis retinoic acid (RA) prolonged survival in high-risk neuroblastoma (NB) patients. Here, we investigated long-term infusion (LTI) of ch14.18 produced in Chinese hamster ovary cells (ch14.18/CHO; 10 × 10 mg/m²; 24 h) in combination with subcutaneous (s.c.) interleukin-2 (IL-2) in a single center program and report clinical response, toxicity and survival. Fifty-three high-risk NB patients received up to 6 cycles of 100 mg/m² ch14.18/CHO (d8-17) as LTI combined with 6 × 10⁶ IU/m² s.c. IL-2 (d1-5; 8-12) and 160 mg/m² oral RA (d19-32). Pain toxicity was documented with validated pain scores and intravenous (i.v.) morphine usage. Response was assessed in 37/53 evaluable patients following International Neuroblastoma Risk Group criteria. Progression-free (PFS) and overall survival (OS) was analyzed by the Kaplan-Meier method and compared to a matched historical control group from the database of AIEOP, the "Italian Pediatric Ematology and Oncology Association". LTI of ch14.18/CHO showed acceptable toxicity profile indicated by low pain scores, reduced i.v. morphine usage and low frequency of Grade ≥3 adverse events that allowed outpatient treatment. We observed a best response rate of 40.5% (15/37; 5 CR, 10 PR), 4-year (4 y) PFS of 33.1% (observation 0.1- 4.9 y, mean: 2.2 y) and a 4 y OS of 47.7% (observation 0.27 - 5.20 y, mean: 3.6 y). Survival of the entire cohort (53/53) and the relapsed patients (29/53) was significantly improved compared to historical controls. LTI of ch14.18/CHO thus shows an acceptable toxicity profile, objective clinical responses and a strong signal of clinical efficacy in NB patients.

Clowns in Paediatric Surgery: Less Anxiety and More Oxytocin? A Pilot Study

Background Hospital stays and medical interventions are accompanied by worries and anxiety in children and parents. Recent studies show that hospital clowns may reduce anxiety and enhance well-being. However, so far studies are based solely on subjective measures and clowns are usually not integrated in medical routine. With this pilot study, we aim to provide both psychological and physiological evidence of positive effects of clowns' interventions in hospitalized children. Patients/Method In a consecutive randomized intervention-control group design with 31 children aged 4 to 13 years, 17 patients were accompanied by a clown prior to surgery or during ward round (intervention group) and 14 were not (control group). Saliva samples for oxytocin measurement were taken from all patients before hospitalization (T1) and prior to surgery or after ward round (T2). Self- and parents-reports were obtained at T1, T2 as well as at time of discharge from hospital (T3) regarding children's anxiety (STAI), worries and well-being. Clowns evaluated their success in cheering up the child. Health professionals were asked for their acceptance of clowns in hospitals. Results Children in the intervention group had lower anxiety ratings and a higher oxytocin concentration at T2 as compared with T1; the control group showed no changes. Parents rated the well-being of their children higher if their child had clown's contact and were more willing to recommend the hospital. The staff judged the clowns as helpful for patients. Discussion Consistent psychological and physiological results suggest the positive impact of a clown's intervention in hospitalized children.

The LXR Ligand T0901317 Acutely Inhibits Insulin Secretion by Affecting Mitochondrial Metabolism

The role of liver X receptor (LXR) in pancreatic β-cell physiology and pathophysiology is still unclear. It has been postulated that chronic LXR activation in β-cells induces lipotoxicity, a key step in the development of β-cell dysfunction, which accompanies type 2 diabetes mellitus. In most of these studies, the LXR ligand T0901317 has been administered chronically in the micromolar range to study the significance of LXR activation. In the current study, we have evaluated acute effects of T0901317 on stimulus-secretion coupling of β-cells. We found that 10 µM T0901317 completely suppressed oscillations of the cytosolic Ca2+ concentration induced by 15 mM glucose. Obviously, this effect was due to inhibition of mitochondrial metabolism. T0901317 markedly depolarized the mitochondrial membrane potential, thus inhibiting adenosine triphosphate (ATP) production and reducing the cytosolic ATP concentration. This led in turn to a huge increase in KATP current and hyperpolarization of the cell membrane potential. Eventually, T0901317 inhibited glucose-induced insulin secretion. These effects were rapid in on-set and not compatible with the activation of a nuclear receptor. In vivo, T0901317 acutely increased the blood glucose concentration after intraperitoneal application. In summary, these data clearly demonstrate that T0901317 exerts acute effects on stimulus-secretion coupling. This observation questions the chronic use of T0901317 and limits the interpretation of results obtained under these experimental conditions.

Clinical and genetic evaluation of patients with KATP channel mutations from the German registry for congenital hyperinsulinism

Congenital hyperinsulinism (CHI) causes hypoglycemia due to irregular insulin secretion. In infants, a rapid diagnosis and appropriate management to avoid severe hypoglycemia is mandatory. CHI is a heterogeneous condition at the clinical and genetic level, and disease-causing genes have been identified in about half of the patients. The majority of mutations have been identified in the ABCC8 and KCNJ11 genes encoding subunits of the KATP channel responsible for two distinct histological forms. The diffuse form is caused by autosomal recessive or dominant inherited mutations, whereas the focal form is caused by a paternally transmitted recessive mutation and a second somatic event. We report on an unselected cohort of 136 unrelated patients from the German CHI registry. Mutations in either the ABCC8 or KCNJ11 gene were identified in 61 of these patients (45%). In total, 64 different mutations including 38 novel ones were detected in this cohort. We observed biparental (recessive) inheritance in 34% of mutation-positive patients, dominant inheritance in 11% and paternal transmission of a mutation associated with a focal CHI type in 38%. In addition, we observed inheritance patterns that do not exactly follow the classical recessive or dominant mode, further adding to the genetic complexity of this disease.

Kidney protein profiling of Wilms' tumor patients by analysis of formalin-fixed paraffin-embedded tissue samples

Wilms' tumor (nephroblastoma, WT) is the most frequent renal cancer in children. However, molecular details leading to WT have not been characterized sufficiently yet. Proteomic studies might provide new insights but are hampered by limited availability of fresh frozen tissue specimen. Therefore, we tested formalin-fixed paraffin-embedded (FFPE) tissue sections routinely collected for pathological inspection for their use in in-depth-proteomic analyses of WT samples in comparison to fresh frozen specimen. The overlap of the proteins identified was over 65%. Thus we used FFPE material from 7 patients for tandem mass spectrometry based comparison of the proteomes of WT and healthy renal tissues. We detected 262 proteins, which were differentially expressed in tumor compared to healthy renal tissue. The majority of these proteins displayed lower levels in the tumor tissue and only 30% higher levels. For selected candidates data were confirmed by immunohistochemical staining. Correlation analysis of blastemal proportions in WT and protein intensities revealed candidates for tumor stratification.

CONCLUSION

This proof of principle proteomic study of FFPE tissue sections from WT patients demonstrates that these archived tissues constitute a valuable resource for larger in-depth proteomic studies to identify markers to follow chemotherapy efficiency or for stratification of tumor subtypes.

Long-term culture and functionality of pancreatic islets monitored using microelectrode arrays

Extracellular recording of the electrical activity of pancreatic islets permits long-term measurements of beta-cell function and reveals oxidant-induced damage and rescue.

Spontaneous vesicoureteral reflux resolution in children: A ten-year single-centre experience

BACKGROUND/AIM

To evaluate the spontaneous resolution rate in infants and young children with vesicoureteral reflux (VUR).

PATIENTS AND METHODS

Paediatric patients with VUR treated in our hospital from January 2000 to December 2010 were retrospectively analyzed. Only patients with pretreatment and follow-up voiding cystourethrogram were included into the study. Treatment success was defined as complete VUR resolution.

RESULTS

The resolution rate for infants less than 1 year of age was 38.6% (17 of 44 renal units). Renal units with mild-moderate VUR (I-III) had a resolution rate of 40% (12 of 30 renal units) compared to 35.7% (5 of 14 renal units) with severe grade (IV-V) VUR. The resolution rate for children over 1 year of age was 39,1% (9 of 23 renal units). Renal units with mild-moderate VUR (I-III) had a resolution rate of 42.9% (9 of 21 renal units) compared to 0% (0 of 2 renal units) with severe grade (IV-V) VUR.

CONCLUSION

Infants less than 1 year of age with nonsymptomatic, mild, moderate or severe VUR have a spontaneous resolution rate of more than 35% and therefore should receive a primary conservative therapy. Children over 1 year of age with nonsymptomatic mild-moderate VUR (I-III) have a spontaneous resolution rate of about 40% and should receive primary conservative treatment as well.

Association of exercise-induced hyperinsulinaemic hypoglycaemia with MCT1-expressing insulinoma

AIMS/HYPOTHESIS

Exercise-induced hyperinsulinism (EIHI) is a hypoglycaemic disorder characterised by inappropriate insulin secretion following anaerobic exercise or pyruvate load. Activating promoter mutations in the MCT1 gene (also known as SCLA16A1), coding for monocarboxylate transporter 1 (MCT1), were shown to associate with EIHI. Recently, transgenic Mct1 expression in pancreatic beta cells was shown to introduce EIHI symptoms in mice. To date, MCT1 has not been demonstrated in insulin-producing cells from an EIHI patient.

METHODS

In vivo insulin secretion was studied during an exercise test before and after the resection of an insulinoma. The presence of MCT1 was analysed using immunohistochemistry followed by laser scanning microscopy, western blot analysis and real-time RT-PCR of MCT1. The presence of MCT1 protein was analysed in four additional insulinoma patients.

RESULTS

Clinical testing revealed massive insulin secretion induced by anaerobic exercise preoperatively, but not postoperatively. MCT1 protein was not detected in the patient's normal islets. In contrast, immunoreactivity was clearly observed in the insulinoma tissue. Western blot analysis and real-time RT-PCR showed a four- to fivefold increase in MCT1 in the insulinoma tissue of the EIHI patient compared with human pancreatic islets. MCT1 protein was detected in three of four additional insulinomas.

CONCLUSIONS/INTERPRETATION

We show for the first time that an MCT1-expressing insulinoma was associated with EIHI and that MCT1 might be present in most insulinomas. Our data suggest that MCT1 expression in human insulin-producing cells can lead to EIHI and warrant further studies on the role of MCT1 in human insulinoma patients.

Hepatitis in an infant treated with octreotide for congenital hyperinsulinism

Congenital hyperinsulinism is characterized by hypoglycemia caused by several genetic disorders of inappropriate insulin secretion. Octreotide, an analogue of somatostatin, plays a major role in the pharmaceutical treatment of this condition. A 9-month-old infant treated with octreotide developed anicteric hepatitis with no other proven cause. After the discontinuation of this drug, the liver enzymes declined rapidly. Liver function tests should be followed in patients receiving octreotide.

Impact of magnetic resonance urography and ultrasonography on diagnosis and management of hydronephrosis and megaureter in paediatric patients

BACKGROUND

(1) To evaluate the diagnostic value of magnetic resonance urography (MRU) in comparison with ultrasonography (US) to determine the extent of upper urinary tract dilation and (2) to evaluate the impact of MRU on therapy management.

MATERIALS AND METHODS

From January 2005 to December 2010, paediatric patients with hydronephrosis or megaureter who underwent MRU in addition to standard work-up imaging were included. Data were retrospectively collected and analysed in comparison with the data obtained from results by US.

RESULTS

Forty-five patients with upper urinary tract dilatation were included into the study. Twenty-six patients (58%) had a hydronephrosis and 19 patients (42%) presented with a megaureter. Diagnosis was established in all patients by multimodulary imaging work-up including micturating cysto-urethrography, MAG3 renography, US and MRU and could be confirmed in all patients who underwent surgery (n = 28). Hydronephrosis was detected in 26 of 26 patients by US (100% sensitivity) and in 25 of 26 patients (96%) by MRU (Not significant (n.s.)). Megaureter was detected in 17 of 19 patients (sensitivity 89%) by US and in 18 of 19 patients (sensitivity 95%) by MRU (n.s.). In all 45 patients, MRU had no impact on surgical or conservative management of hydronephrosis or megaureter.

CONCLUSION

In our experience, MRU was not superior to US in detecting hydronephrosis or megaureter and had no impact on the surgical or conservative management of upper urinary tract dilation.

Mucoepidermoid carcinoma of the lung in a 6-year-old boy

Primary malignant lung tumours, especially the mucoepidermoid cancer of the bronchus, are very uncommon in childhood. Obtaining the diagnosis might be difficult due to unspecific initial symptoms but early detection and treatment is crucial for a good long-term survival. Bronchoscopy is considered the "gold standard" for making the diagnosis. The recommended therapy for a mucoepidermoid lung cancer is sleeve lobectomy with favourable overall survival after complete resection. We report the case of a 6-year-old boy with a right-upper-lobe bronchus tumour. The histological examination revealed a low-grade mucoepidermoid carcinoma.

A rare case of an isolated triquetrum body fracture in a 14-year-old boy

Isolated carpal fractures are uncommon injuries usually caused by a fall on the outstretched hand. The patient might present with non-specific clinical signs and X-ray diagnosis might be difficult due to bone overlay. An isolated triquetrum body fracture is an absolute rarity. The treatment is easy and the outcome excellent but if missed, degenerative changes with chronic pain and impaired movement might be the consequence.

Self-bougienage of oesophageal stricture by an 8-year-old child

Oesophageal corrosive injuries have a high potential to result in stricture formation with the requirement for repeat oesophageal dilation. Especially in children, oesophageal bougienage is performed under general anaesthesia or strong sedation. In developing countries without comprehensive medical care, this service might not be available. We report the case of daily oesophageal self-bougienage performed by an 8-year-old Afghan child as highly effective treatment of recurrent oesophageal stricture formation after caustic substance ingestion.

Gastric teratoma in a 6-month-old boy

Gastric teratomas are very rare embryonal neoplasms, accounting for 2.6% of all perinatal diagnosed germ cell tumours. About 85% are well-differentiated mature lesions and about 15% are immature tumours with the potential of malignant transformation. The recommended therapy for gastric teratomas is surgical excision. We present the case of a 6-month-old boy with an incidentally detected epigastric mass. The histological examination revealed a mature gastric teratoma. The diagnostic imaging, therapy and postoperative follow-up are discussed.

Malignant pancreatic tumors in children and young adults: evaluation of 228 patients identified through the Surveillance, Epidemiology, and End Result (SEER) database

BACKGROUND

Malignant pancreatic tumors are rare in young patients, few epidemiologic data are available. We reviewed prognostic factors and outcome of 228 patients <30 years with malignant pancreatic tumors identified through the U.S. National Cancer Institute's SEER (Surveillance, Epidemiology, and End Results) Public-use Database from 1973 to 2004.

METHODS

Cases were grouped using the ICD-O-3. 5-year overall survival (OAS) was assessed by gender, ethnicity, SEER stage, and 5-year age intervals using univariate and Cox regression analysis.

RESULTS

228 patients with malignant pancreatic tumors were identified, resulting in an incidence of 0.46/million (100 carcinomas, 85 endocrine tumors, 8 solid pseudopapillary neoplasms (SPN), 11 pancreatoblastomas) in the USA. OAS was worse in males than females (37% vs. 55%, p=0.005). OAS according to stage was 87%, 68%, 21% for local (n=54), regional (n=42), distant metastatic disease (n=108), respectively. OAS of patients with carcinoma was 33%, endocrine tumors 58%, SPNs 88%, pancreatoblastomas 66%. Cox regression revealed stage (p=< 0.001), histology (p=< 0.001), age group (p=0.05) to be independent prognostic factors.

CONCLUSION

Malignant pancreatic tumors are extremely rare in children and young adults. Entities change over the age groups towards more carcinomas with worse outcome in older patients. Tumor stage, histology and age group are important predictors for outcome. International collaboration is needed to learn more about pediatric pancreatic tumors.

Techniques in pediatric surgery: congenital hyperinsulinism

For surgery in congenital hyperinsulinism (CHI), a distinct surgical strategy and technique is required for focal, diffuse and atypical CHI. In focal CHI, a confined, localized and parenchyma-sparing resection which is guided by the PET-CT is always indicated in order to cure the patient. In diffuse CHI, however, the results of surgical therapy are unpredictable and cure is an exception. Therefore, a strong tendency exists nowadays that medical therapy should be preferred in diffuse CHI. In atypical CHI the situation is more complex: if the focal lesion or the segmental mosaic are not too extensive, cure by resection should be possible. But care must be taken in atypical cases not to resect too much of the gland in order not to induce diabetes.

Techniques in pediatric surgery: congenital hyperinsulinism

For surgery in congenital hyperinsulinism (CHI), a distinct strategy and technique is required for focal, diffuse and atypical types. In focal CHI, a confined, localized and parenchyma-sparing resection which is guided by the PET-CT is always indicated in order to cure the patient. In diffuse CHI, however, the results of surgical therapy are unpredictable and cure is an exception. Therefore, a strong tendency exists nowadays that medical therapy should be preferred in diffuse CHI. In atypical CHI the situation is more complex: if the focal lesion or the segmental mosaic are not too extensive, cure by resection should be possible. But care must be taken in atypical cases not to resect too much of the gland in order not to induce diabetes.

Visualization of the focus in congenital hyperinsulinism by intraoperative sonography

In surgery for focal congenital hyperinsulinism (CHI), the identification and complete resection of the focus without collateral damage is of utmost importance. In a pilot study we applied intra-abdominal high-frequency sonography during surgery for focal CHI in 2 infants. The focus could be identified, its relation to the pancreatic and common bile duct could be shown, and the typical octopus-like tentacles could be demonstrated. In one case the resection was successful; in the other it was not. These preliminary results suggest that intraoperative sonography could be a valuable tool in the surgical therapy of focal CHI and warrants further evaluation in a clinical study.

Positron emission tomography/computed tomography diagnostics by means of fluorine-18-L-dihydroxyphenylalanine in congenital hyperinsulinism

The unfavorable prognosis of congenital hyperinsulinism (CHI) can be avoided if the patients are treated with high-dose glucose infusions and timely surgical intervention. Circumscribed foci used to be identified by selective percutaneous pancreatic vein catheterization and determination of the insulin level. Fluorine-18-L-dihydroxyphenylalanine-positron emission tomography (PET) was developed as a milder alternative for diagnostic localization of focal disease. The uptake of fluorine-18-L-dihydroxyphenylalanine is considerably increased in foci with high insulin synthesis rates. In Berlin, diagnosis was achieved by high definition PET/computed tomography with multiphase contrast media protocols that provided all necessary data with one investigation. We have investigated 135 patients with congenital hyperinsulinism, including 45 patients with focal disease (33.3%). All the foci were excised on the basis of PET/computed tomography images. The German data demonstrate that 87% to 91% of the operated patients could be completely healed.

Surgery in congenital hyperinsulinism-tips and tricks not only for surgeons. A practical guide

Each form of congenital hyperinsulinism (CHI)-focal, diffuse, atypical-requires its own surgical strategy and technique. Focal CHI is treated by a positron emission tomography/computed tomography-guided, local resection which is confined only to the lesion. As much healthy pancreatic tissue as possible is preserved. On the contrary, the therapeutic mainstay of diffuse CHI must be conservative nowadays. Only in the exceptional cases in which medical treatment fails surgical therapy is warranted to prevent hypoglycemia. However, the extension of resection that is able to cure hyperinsulinism while avoiding diabetes is not known today. The outcome, therefore, is unpredictable. In the rare atypical cases it is important to stop the resection at the right time in order not to finish unnecessarily with a mutilating operation.

Intraoperative sonography: a technique for localizing focal forms of congenital hyperinsulinism in the pancreas

Congenital hyperinsulinism (CHI), syn. nesidioblastosis, is the most frequent cause of persistent, recurrent hypoglycemia in infancy. One third of patients show a single circumscribed focus. Enucleation of the focus and the removal of all affected β-cells with preservation of healthy tissue is the treatment of choice. The intrapancreatic choledochus as well as the ductus pancreaticus major must remain intact. The diagnostic gold standard is 18F-DOPA-PET/CT. Intraoperative sonography is carried out to correctly visualize the focus preoperatively localized by PET/CT in situ during the operation. The enucleation of the focus was carried out 3 - 20 days after PET/CT in 5 patients at an age of 3.5 - 14 months. Intraoperative ultrasound was carried out with high-capacity devices of different manufacturers under use of broadband probes (9 - 14 MHz). The localization by intraoperative ultrasound was accurate in all 5 patients with focal CHI, with regard to the intraoperative localization as previously described by PET/CT and histology. D. choledochus and D. pancreaticus major were separated intraoperatively by ultrasound. 3 of 5 patients were cured by complete enucleation of the focus. Nevertheless, the entire intraoperative identification of the segmented focus is still problematic. Characteristic sonographic features of a CHI focus are: hypoechogenicity, variable homogeneous and inhomogenous texture, blurred, irregular limitation without capsule, filiform, lobular processes, and insular dispersal into the surrounding tissue. Intraoperative high-resolution sonography helps the pediatric surgeon to determine size, configuration and topography of a CHI focus.

Proteome analysis reveals new mechanisms of Bcl11b-loss driven apoptosis

The Bcl11b protein was shown to be important for a variety of functions such as T cell differentiation, normal development of central nervous system, and DNA damage response. Malignant T cells undergo apoptotic cell death upon BCL11B down-regulation, however, the detailed mechanism of cell death is not fully understood yet. Here we employed two-dimensional difference in-gel electrophoresis (2D-DIGE), mass spectrometry and cell biological experiments to investigate the role of Bcl11b in malignant T cell lines such as Jurkat and huT78. We provide evidence for the involvement of the mitochondrial apoptotic pathway and observed cleavage and fragments of known caspase targets such as myosin, spectrin, and vimentin. Our findings suggest an involvement of ERM proteins, which were up-regulated and phosphorylated upon Bcl11b down-regulation. Moreover, the levels of several proteins implicated in cell cycle entry, including DUT-N, CDK6, MCM4, MCM6, and MAT1 were elevated. Thus, the proteome data presented here confirm previous findings concerning the consequences of BCL11B knock-down and provide new insight into the mechanisms of cell death and cell cycle disturbances induced by Bcl11b depletion.

Serum levels of Midkine in children and adolescents without malignant disease

BACKGROUND

Midkine (MK), a heparin-binding growth factor, is a secreted protein and can be detected in a patient's sera.

METHOD

MK was studied in the sera of 215 children and adolescents without malignant disease using an enzyme-linked immunosorbent assay in order to determine the distribution of concentrations in a control population for pediatric oncology patients. Tested subjects either underwent surgical procedures or suffered from endocrinological diseases.

RESULTS

Elevated MK levels were found in patients with short stature, diabetes mellitus, obesity, and cleft lip and palate. These patients were subsequently excluded from the "non-cancer" group. MK serum levels did neither correlate with sex, age, weight or height nor showed a normal distribution (n= 152, range: 0.0-5.58 ng/ml, median: 0.0 ng/ml, mean: 0.26 ng/ml, SD: +/-0.61).

CONCLUSION

MK serum values in children and adolescents are widely spread and not normally distributed. The present results indicate that the MK expression is influenced by many factors apart from cancer, which have not yet been identified.

[Development of pediatric surgery in the next 20 years]

Pediatric surgery focuses not on an anatomic region or organ system, but on the development of a growing human being according to age. Recently, a tendency to reduce and to downgrade pediatric surgery could be observed which is due to economic reasons and an alarming lack of trained surgeons. Just as 60 years ago, general surgeons continue to operate on infants and children. However, this is a step backwards and an anachronism. Children are not small adults and pediatric surgery can be distinguished from adult surgery in many aspects, such as the spectrum of surgical diseases, the congenital malformations and frequently the indications and techniques of surgery. Pediatric surgeons, however, by themselves should specialize in centers which are focused on rare and complex diseases. Pediatric surgery should not be separated in the hospital, but integrated in a network with general surgery, traumatology, pediatrics, neonatology and specialists of the other surgical disciplines. Strict patient age limitations are not compatible with the individuality of adolescents and should be avoided. A well-equipped clinic for pediatric surgery is expensive, but a mandatory investment in the future!

Interstitial cells of Cajal in the vermiform appendix in childhood

BACKGROUND AND AIMS

The interstitial cells of Cajal (ICC) have not yet been investigated in the vermiform appendix. They are important for the peristalsis of the gastrointestinal tract and have been found to be altered in various motility disorders. Motor disturbance has been suggested as a possible contributor in the unclear etiology of appendicitis. We wanted to examine the distribution of the ICC in the vermiform appendix. Furthermore we investigated whether ICC are altered in persons with appendicitis.

METHODS

We investigated the ICC distribution in 28 appendices of children using immunohistochemistry and anti-c-kit antibodies. Cells and processes were quantified in normal, acute and chronic inflamed appendices.

RESULTS

IC(C)-CM and IC(C)-LM were found in the circular and longitudinal muscle layers, respectively. IC(C)-LM, however, were scarce and inhomogeneous in contrast to the IC(C)-CM. The functionally important subgroups of the colon, the IC(C)-SM and IC(C)-MP, however, could not be detected in the appendix with the used antibody. There was no difference in the distribution of detected ICC between normal and inflamed appendices.

CONCLUSION

IC(C)-LM are altered and IC(C)-SM and IC(C)-MP are lost in the vermiform appendix with no differences between healthy and inflamed tissue and without a correlation to appendicitis. Thus, other factors must be considered in the etiology of appendicitis.

Evaluation of [18F]fluoro-L-DOPA positron emission tomography-computed tomography for surgery in focal congenital hyperinsulinism

CONTEXT

In congenital hyperinsulinism (CHI), the identification and precise localization of a focal lesion is essential for successful surgery.

OBJECTIVE

Our objective was to evaluate the predictive value and accuracy of integrated [18F]fluoro-L-DOPA ([18F]FDOPA) positron emission tomography (PET)-computed tomography (CT) for the surgical therapy of CHI.

DESIGN

This was an observational study.

SETTING

The study was performed in the Department of Pediatric Surgery at a university hospital.

PATIENTS

From February 2005 to September 2007, 10 children with the clinical signs of CHI and an increased radiotracer uptake in a circumscribed area of the pancreas in the [18F]FDOPA PET-CT were evaluated.

INTERVENTIONS

Guided by the [18F]FDOPA PET-CT report, all children underwent partial pancreatic resection, in two cases twice.

MAIN OUTCOME MEASURES

Correlation of the anatomical findings at surgery with the report of the [18F]FDOPA PET-CT, and the results of surgery and clinical outcome were determined.

RESULTS

In nine children the intraoperative situation corresponded exactly to the description of the [18F]FDOPA PET-CT. A limited resection of the pancreas was curative in eight cases at the first surgery, in one case at the second intervention. We observed no diabetes mellitus or exocrine insufficiency in the follow up so far. In one child, hypoglycemia persisted even after two partial resections of the pancreatic head. Histological analysis finally revealed an atypical intermediate form of CHI.

CONCLUSIONS

The integrated [18F]FDOPA PET-CT is accurate to localize the lesion in focal CHI and is a valuable tool to guide the surgeon in limited pancreatic resection.

Extrahepatic biliary atresia and caudal regression syndrome in an infant of a diabetic mother

Although most cases of extrahepatic biliary atresia are thought to result from perinatal obliterating inflammation, some are associated with a faulty morphogenesis. The authors report on a baby girl of a mother with ill-managed insulin-dependent diabetes mellitus. The baby presented with sacro-coccygeal agenesis, clubfoot, and ano-urinary incontinence. In addition, there was polysplenia, no inferior vena cava, and the portal vein was grossly distorted. Progressive conjugated hyperbilirubinemia prompted liver biopsy at 4 weeks of age, showing intracanalicular cholestasis without fibrosis. The diagnosis of extrahepatic biliary atresia was confirmed during laparotomy performed for hepatoportojejunostomy. Some cases of extrahepatic biliary atresia might be part of a spectrum of malformations associated with maternal diabetes mellitus.

Significance of heparin-binding growth factor expression on cells of solid pediatric tumors

BACKGROUND

The heparin-binding growth factors pleiotrophin (PTN), midkine (MK), vascular endothelial growth factor (VEGF), and basic fibroblast growth factor (bFGF) stimulate tumor cell proliferation and angiogenesis. In this study the authors wanted to know if these growth factors are expressed by cell lines and tumor tissue of solid pediatric tumors, growth factor expression is influenced by proinflammatory cytokines, and local growth factor concentration has an influence on experimental tumor growth.

METHODS

Growth factor mRNA expression was analyzed by reverse transcriptase polymerase chain reaction (RT-PCR) and protein secretion by enzyme-linked immunosorbent assay (ELISA). Neuroblastoma cells were suspended in solutions containing different growth factor concentrations before injection into the nude mice, which were given pentosan polysulfate (PPS) for antagonism.

RESULTS

The analyzed growth factors were expressed by most cells of solid malignant pediatric tumors. Their expression was not influenced by proinflammatory cytokines. The inhibition of tumor growth by PPS in the nude mouse model was dependent on the local growth factor concentration. High concentration excluded significant tumor suppression.

CONCLUSIONS

Because of the redundancy of growth factor expression and the abolishment of PPS efficacy by a high local growth factor concentration, the authors conclude that overall targeting of growth factors is a promising approach to cancer therapy in childhood.

Transient renal insufficiency by bilateral renal cysts and posterior urethral valves

Renal insufficiency developed in a newborn with huge bilateral renal cysts and posterior urethral valves. Definitive therapy consisted of laser coagulation of the valves and transient percutaneous drainage of the cysts.

Laser resection of posterior urethral valves

Laser resection (LR) of posterior urethral valves during infancy as early as possible after diagnosis appears to represent a safe and reliable method. In contrast to other procedures, LR allows valve ablation with thin cystoscopes and carries little risk, even in premature and newborn infants. Its application in seven children in the course of 2 years principally confirmed its suitability for use: it could be applied in all cases without any problems and led to extensive resection of the valve tissue and removal of the obstruction in all patients. The encouraging clinical findings were confirmed by control cystoscopies and micturating cystourethrograms. Complications arising from the method were not observed.

Critical role of nitric oxide for proliferation and apoptosis of bone-marrow cells under septic conditions

Sepsis is a state of high turnover of bone-marrow cells. Nitric oxide (NO) is reported to be involved in cell proliferation and demise. Murine bone-marrow cells were incubated with lipopolysaccharide together with tumor necrosis factor alpha, interferon gamma and interleukin-1 beta for 48 h. The basal proliferation rate of the cells remained unchanged, but granulocyte-macrophage colony stimulating factor-induced proliferation was suppressed and the percentage of apoptotic cells significantly raised. Levels of nitrite in the culture supernatants were inversely correlated with the suppression of proliferation, but directly correlated with apoptosis. The NO synthesis inhibitor N-methyl-arginine inhibited the suppression of proliferation as well as the induction of apoptosis and NO synthesis. Our results indicate that NO is a negative feedback regulator of cell turnover in sepsis, which limits growth-factor-induced proliferation and induces apoptosis of bone marrow cells.

Ceramide induces apoptosis in neuroblastoma cell cultures resistant to CD95 (Fas/APO-1)-mediated apoptosis

BACKGROUND/PURPOSE

Spontaneous tumor regression is a well-known characteristic in neuroblastomas. Because preliminary reports have shown that regression may be caused by apoptosis (a lethal cascade mediated by the CD95 (APO-1/Fas)-receptor), we analyzed the expression of CD95-receptors in 5 human neuroblastoma cell lines. Ceramides (known stimuli of apoptosis downstream from the CD95-receptor complex) also were used to test whether apoptosis would be induced in neuroblastoma cell cultures resistant to CD95-mediated programmed cell death.

METHODS

The expression of the CD95-receptor was assessed by flow cytometry after incubation with either fluorisothiocyanate-conjugated (FITC) anti-CD95-antibody (UB2) or CD95-ligand for 16 hours. Apoptotic cell death was detected via microscopy, cell viability testing (MTT, 3-[4,5 dimehylthiazole-2-yl]-2,5 diphenyltetrazoliumbromide), and flow cytometric analysis after propidium iodide staining of the DNA.

RESULTS

CD95-receptor expression was found on all neuroblastoma cell lines. Stimulation of the CD95-receptor of the malignant glioblastoma cell line LN229 (positive control) with either anti-CD95-antibody or CD95-ligand induced apoptosis. Apoptosis was not seen, however, in any of the neuroblastoma cell lines when the CD95-receptor was stimulated with anti-CD95-antibody or the CD95-ligand. Significant apoptosis was detected in all neuroblastoma cell lines after the addition of 25 micromol/L C2- and C6-ceramide.

CONCLUSIONS

CD95-receptors are present on neuroblastoma cell lines, and these cells are resistant to apoptosis stimulated by anti-CD95-antibody or CD95-ligand. Apoptosis is induced, however, when these cells are treated with ceramide. A signal blockage downstream from the CD95-receptor complex and upstream of ceramide may account for this finding, and the "cellular FLICE inhibitory protein" (cFLIP) may be primarily responsible.

Impact of experimental peritonitis on bone marrow cell function

BACKGROUND

The effects of abdominal sepsis on the regulation of cell turnover in bone marrow and on the function of hematopoietic stem cells were investigated.

METHODS

In a new mouse model of abdominal sepsis (colon ascendens stent peritonitis [CASP]) the proliferation, apoptosis, and colony-forming capacity of bone marrow cells were determined.

RESULTS

Both experimental peritonitis and sham surgery increased proliferation of bone marrow cells significantly (P < .01). Incubation with granulocyte-macrophage colony-stimulating factor but not granulocyte colony-stimulating factor further augmented proliferation of bone marrow cells from septic mice. In contrast to cell proliferation, bone marrow cell apoptosis was significantly (P < .001) increased in response to CASP but not to sham surgery. CASP surgery and treatment of normal bone marrow cells with lipopolysaccharide, tumor necrosis factor-alpha, interleukin 1 beta, and interferon gamma increased the number of apoptotic cells to a similar extent. Stem cell assays revealed that during the late phase of peritonitis the colony formation by granulocytic-monocytic precursors was increased, whereas mature erythroid colony-forming cells were suppressed. Incubation of normal bone marrow cells with lipopolysaccharide and cytokines showed similar effects.

CONCLUSIONS

These results reveal differential effects of experimental peritonitis on various hematopoietic lineages and suggest a potential role of inflammatory mediators for the dysregulation of bone marrow cell function during abdominal sepsis.