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Biomedical subjects

D von Schweinitz

Publications and source records attributed to D von Schweinitz.

At least 19 recordsLinked to original sources
PubMed2006

Peritonitis in childhood: clinical relevance of cytokines in the peritoneal exudate.

BACKGROUND: The aim of the study was to assess pro-inflammatory cytokine (tumor necrosis factor alpha [TNF-alpha], interleukin 6 [IL-6]) and anti-inflammatory cytokine (interleukin 10 [IL-10]) responses in children with peritonitis secondary to hollow viscus perforation, and to evaluate the influence of peritoneal microbial status on cytokine expression and morbidity. METHODS: The peritoneal fluid of 13 children with perforated appendicitis was examined with qualitative analysis of bacteria, and measurement of cytokine levels, which were compared to cytokine plasma levels, over a five-day period following operation. RESULTS: All fluid specimens showed permanently elevated levels of TNF-alpha and IL-10. IL-6 tended to decrease to normal levels by the 5th postoperative day. Peritoneal exudate levels of TNF-alpha and IL-10 were more than 100 - 1000 times greater than those in plasma. The most common bacterial species isolated in the peritoneal fluid was Escherichia coli. Despite persisting high cytokine concentrations and bacterial load of the peritoneal cavity for 5 days postoperatively, the children recovered uneventfully and the systemic signs of infection disappeared rapidly. CONCLUSION: Neither the bacterial nor the pro-inflammatory cytokine load of the peritoneal cavity proved to be associated with the clinical course. We hypothesize that in peritonitis in childhood a significant and clinically relevant cytokine-mediated inflammatory response is compartmentalized in the peritoneal cavity. Therefore adjuvant surgical measures in addition to appendectomy and intraoperative debridement seem not to be necessary, at least for peritonitis due to perforated appendicitis in children.

Adolescent↗
PubMed2006

Tumor model for laparoscopy in pediatric oncology: subperitoneal inoculation of human hepatoblastoma cells in nude rats.

BACKGROUND: Minimally invasive surgery (MIS) for diagnostic or even ablative purposes in pediatric oncology is gradually evolving, but little is known about its biological consequences and surgical complications. Especially for hepatoblastoma (HB), no study on the influence of laparoscopy is available yet. A special tumor model could facilitate a variety of investigations. The present study introduces a laparoscopic technique to create subperitoneal metastases of human HB. METHODS: 7 immuno-incompetent (rnu/rnu) rats (mean weight 198 g) received a stab incision in the lower abdomen to insert a 4 mm scope. Under laparoscopic guidance (CO2 pressure of 1 mmHg, flow of 0.2 l/min) an 18 G needle was introduced, to inject several subperitoneal deposits of the tumor cell suspension (HuH6, 3 x 10 (6) in 1 ml of RPMI-1640 medium). Tumor growth was allowed for 6 - 7 weeks and finally the animals were laparoscopically evaluated for peritoneal metastases. Each suspicious lesion was harvested for histology. RESULTS: One animal was investigated after 6 weeks without evidence of tumor growth. After 7 weeks, in 4 out of 6 animals at least one lesion could be detected. Histology revealed HB in all specimens. CONCLUSION: Subperitoneal inoculation of human HB cells in nude rats achieves intraabdominal tumor growth. The present model allows a variety of laparoscopic strategies and their oncological impact to be studied. Thus it may contribute to the development of distinct oncological concepts for MIS in children with HB.

Animals↗
PubMed2005

Videoscopic fluorescence diagnosis of peritoneal and thoracic metastases from human hepatoblastoma in nude rats.

BACKGROUND: Various medical disciplines are employing photodynamic diagnosis (PDD) when searching for malignancies. It is still unknown whether pediatric solid tumors such as hepatoblastoma are susceptible to this technique as well. METHODS: Human hepatoblastoma cells were injected into the abdomen or right thoracic cavity of nude rats. Tumor growth was allowed for 7 weeks. Then, photosensitization was induced by peritoneal lavage with 5-aminolevulinic acid (ALA). Applying the Storz PDD system and one 4-mm scope, all animals were investigated by videoscopic white light diagnosis (WD) and PDD. Suspicious lesions were marked and analyzed by spectrometry and histology. RESULTS: Positive fluorescence was documented for every tumor seen by WD in the abdomen or right thoracic cavity. Spectrometry of lesions showed a 6.34-fold increased fluorescence intensity. Histology revealed hepatoblastoma in all specimens. CONCLUSIONS: Human hepatoblastoma can be detected by PDD in a rat model. Considering the clinical success of this method in other specialties, our findings indicate that further investigations to evaluate the benefit of PDD for children with hepatoblastoma should be performed.

Animals↗
PubMed2005

Acute epididymitis in children: a 4-year retrospective study.

OBJECTIVE: To evaluate the incidence of acute epididymitis (AE) compared to testicular torsion (TT) as a form of acute scrotum in children, to describe clinical aspects and to assess the value of laboratory tests and radiological investigations in AE. METHODS: Retrospective review of the medical records of 49 patients presenting with clinical aspects of AE over a 4-year period; evaluation of clinical features, laboratory tests (blood, urine), radiological examinations (duplex and real-time ultrasound, renal sonography, voiding cysturethrography [VCUG]) and urodynamics. RESULTS: 49 patients with an overall mean age of 9.8 years (range 0.2-15.3 years) presented with AE. In the same period, 31 subjects required surgery for TT. Local pain on palpation of the epididymis and spontaneous pain in the testis and/or epididymis were the most common clinical signs. In 2 patients, urine cultures revealed significant bacteriuria. Duplex and real-time ultrasound showed no false negative result. 41% of the patients revealed concomitant urological diseases, but only in 1 patient was treatment influenced by the uropathy. 16/21 older boys (76%) demonstrated normal uroflow patterns. CONCLUSION: AE seems to be more common than acute TT. Urinalysis and urine culture should be performed for all children with AE. High resolution ultrasound with an experienced investigator is able to exclude TT reliably so that routine surgical exploration is seldom necessary.

Acute Disease↗
PubMed2004

A case of virilised female with urethral duplication and valve formation.

We report the case of a female (chromosomal 46 XX) with a complex congenital urogenital malformation. Caesarian section was performed at the 30th gestational week due to hydrops fetalis and polyhydramnion. Clinical and radiological evaluation demonstrated a complex urogenital malformation with an enlarged penoclitoral organ, urethral duplication, and concomitant malformations. The girl presented with a female urethra with a vaginal orificium as well as a male urethra culminating in a microphallus. Additionally, a urethral valve formation just cranial to the bifurcation of the male and female urethra was also present. Due to concomitant diseases, a complicated clinical course and recurrent urinary tract infections, the final operative correction resulting in a female phenotype, was performed at the age of 2 (1/2) years as a single-stage procedure.

Disorders of Sex Development↗
PubMed2003

Minimally invasive repair of pectus excavatum (MIRPE)--the Basel experience.

PURPOSE: Minimally invasive repair of pectus excavatum (MIRPE) was first reported in 1998 by D. Nuss. This technique has gained wide acceptance during the last 4-5 years. In the meantime, some modifications of the technique have been introduced by different authors. Our retrospective study reports our own experience over the last 36 months and modifications introduced due to a number of complications. METHODS: From 3/2000 to 3/2003, 22 patients underwent MIRPE. Patients median age was 15.5 years (10.7 to 20.3 years). Standardised preoperative evaluation included 3D computerised tomography (CT) scan, pulmonary function tests, cardiac evaluation with electrocardiogram and echocardiography, and photo documentation. Indications for operation included at least two of the following: Haller CT index > 3.2, restrictive lung disease, cardiac compression, progression of the deformity and severe psychological alterations. RESULTS: In 22 patients (2 girls, 20 boys) undergoing MIRPE procedure, a single bar was used in 21 patients and two bars in one boy. Lateral stabilisers were fixed with non resorbable sutures on both sides. Overall, postoperative complications occurred in six patients (27.3%). In two patients (9.1%) a redo-procedure was necessary due to bar displacement. An additional median skin incision was performed in two patients to elevate the sternum. Pneumothorax or hematothorax in two patients resulted in routine use of a chest tube on both sides. Long-term favourable results were noted in all patients. CONCLUSIONS: The MIRPE procedure is an effective method with elegant cosmetic results. Modifications of the original method help to decrease the complication rate and to accelerate acquirement of expertise.

Adolescent↗
PubMed2002

Renal dysplasia in children with posterior urethral valves: a primary or secondary malformation?

Routine prenatal ultrasound examination of the urogenital tract is of importance in patients with posterior urethral valves (PUV), because the renal function and long-term prognosis of these patients depend on early diagnosis and subsequent therapy. Opinion is divided as to whether the often-observed association of PUV with renal dysplasia represents a primary malformation or a secondary pathology caused by recurrent infections. These aspects should have an influence on therapeutic consequences and optimal timing of therapy in order to preserve long-term renal function. The histology of kidney specimens from 13 children with PUV who underwent nephrectomy was reviewed to attempt to differentiate between primary dysplastic malformations and secondary pathologies. Clinical data were analyzed and compared with the histologic findings. The average age at nephrectomy was 29 months (range 3-158 months). Approximately 80% of the specimens showed primary dysplastic malformations (mesenchymal or fetal cartilage tissue or dysplastic glomeruli and tubuli) in the presence of well-developed renal parenchyma. All specimens showed secondary pathologies such as renal-cortical atrophy, interstitial fibrosis, and interstitial-nephritis atrophy. The histologic evidence of well-differentiated renal parenchyma in concurrence with dysplastic parenchyma makes infravesical obstruction as the only cause of renal alterations in patients with PUV questionable. This coincides with the fact that organogenesis of the kidney is terminated at the 12th gestational week and secondary renal damage is irreversible at the 20th gestational week, but prenatal urinary diversion of the upper urinary tract is feasible in the 20th gestational week at the earliest. These facts must be taken into account when considering intrauterine urinary diversion.

Humans↗
PubMed2002

Characteristics and outcome of thoracic neuroblastoma.

It has been reported by several groups that thoracic neuroblastoma (NB) are associated with a better outcome than NB of other localisation. Concerning the reason for this phenomenon, however, the findings have diverged and therefore therapeutic recommendations are not uniform. We performed a retrospective analysis of the prognostic factors and surgical results of 113 thoracic NB and compared these to 556 NB of other sites, all treated according to the protocol of the German Cooperative Study NB90. Compared to non-thoracic NB, thoracic NB showed a female preponderance (P = 0.018), more often with localised disease stages 1 - 3 (P < 0.001), lower LDH serum levels (P = 0.027), and less often with MYCN amplification (P = 0.04), while there was no statistically significant difference in the patients' ages and histological grades. In a separate analysis of localised (stages 1 - 3), stage 4 and stage 4 S NB, there were no differences between thoracic and non-thoracic NB in LDH secretion. MYCN amplification was different only in localised NB (P = 0.037). In a multivariate analysis, tumour stage (P < 0.0001), MYCN-status (P < 0.001) and serum-LDH (P = 0.008), but not thoracic localisation, were independent prognostic factors. A complete resection was achieved in 73/104 (70 %) operated thoracic NB, while 25 (24 %) were partially resected and 6 (6 %) only biopsied. Patients with thoracic NB had a better outcome only in stage 4, but not in stages 1 - 3 and 4 S (EFS; P = 0.028). There was no difference for all stages in the event-free survival between completely and incompletely resected tumours. Surgical complications occurred in 34 (20 %) of all operations, some of them severe, although there were no surgical deaths. Our results suggest that although thoracic NB has a relatively favourable prognosis, it should be treated in the same way as NB with non-thoracic localisation, with stratification according to tumour stage and biological properties, such as MYCN status. Radical surgery is only indicated if mutilation and life-threatening complications can be avoided.

Antineoplastic Agents↗
PubMed2002

The impact of surgical radicality on outcome in childhood neuroblastoma.

AIM: Improvement of treatment results for neuroblastoma (NB) has been achieved during recent years, especially by intensifying therapy for advanced NB. Surgery, however, has not contributed very much to this progress and there is still controversy regarding the best approach for high-risk NB. We therefore attempted to find criteria for a differentiated strategy for tumour resection in NB. METHODS: We retrospectively analysed the data of 2251 NB patients treated in the German Cooperative NB Studies NB79 - NB97 (1979 - 1999) including patients' age, tumour stage, MYCN oncogene status, surgical intervention, completeness of resection, surgical complications and outcome. RESULTS: 1148 patients had a localised NB (stage 1 - 3), 878 had stage 4, and 225 had stage 4 S disease. 2112 patients underwent surgery. Tumour resection as the final result of primary or delayed operation was complete in 1403 (66.4 %), incomplete in 449 (21.3 %), and only a biopsy was carried out in 260 (12.3 %) cases. Complete resection was performed most often in localised NB (73.5 %), less often in stage 4 NB (59.2 %) and in stage 4 S (54.5 %). Clinically relevant complications occurred in 19.2 % of all operations independent of the time of resection during treatment, patients' age, tumour stage, tumour site and MYCN status. For 1787 patients from the studies NB79 - NB90 the probability of 5-year event-free survival (EFS) could be analysed and correlated with surgical radicality. In localised NB of patients aged > 1 year there was a significant difference in 5-year EFS between complete, incomplete, and no substantial resection ( P < 0.0001), while this was not the case in infants < 1 year. In the early study period (NB79 - NB85) patients with stage 4 NB had a significantly better 5-year EFS after complete excision of the primary tumour. In contrast, this difference was not confirmed during the later period (NB90) with intensified drug therapy. Timing of surgery did not influence prognosis. For infants with stage 4 S NB there was no difference in outcome after complete or incomplete resection of the primary tumour. MYCN status did not alter the significant relevance of tumour resection for outcome in localised NB. In contrast to MYCN non-amplified stage 4 NB, however, stage 4 NB with MYCN amplification had a significantly better outcome if the primary tumour could be completely or incompletely resected, compared to a biopsy only. CONCLUSIONS: Radical tumour resections with the risk of surgical complications are only justified in children > 1 year with a localised NB. In stage 4 NB, the primary tumour may be resected during intensive multimodal treatment without risky complications. Complete or incomplete resection of the primary tumour improves prognosis only in MYCN-amplified stage 4 NB. Stage 4 S NB with non-amplified MYCN are subject to spontaneous regression; a resection after chemotherapy may be indicated in cases of non-sufficient regression or growth of the primary tumour.

Clinical Trials as Topic↗
PubMed2001

Methylation changes in the human IGF2 p3 promoter parallel IGF2 expression in the primary tumor, established cell line, and xenograft of a human hepatoblastoma.

Hepatoblastoma (HB) is a rare malignant embryonal liver tumor. Its pathogenesis has been associated with altered regulation of the IGF2 and H19 genes, and previous studies have suggested a correlation between abnormal methylation and altered expression of these genes in hepatoblastoma. Upregulation of the activity of the IGF2 promoter P3 has previously been shown to be tightly correlated with demethylation in hepatoblastoma. Here, we have used bisulfite genomic sequencing to characterize the methylation pattern of the IGF2 promoter P3 in the hepatoblastoma-derived cell line Hep T1, in the original tumor from which Hep T1 is derived, and in nude mouse xenografts of the Hep T1 cell line. The results show a clear difference in methylation pattern of the most proximal region of the IGF2 P3 promoter between the primary tumor, the cell line, and the xenografts. RNase protection and mRNA in situ hybridization revealed that variations in methylation patterns was paralleled by the levels of IGF2 P3 mRNA, which was detectable in the primary tumor and xenografts, but not in the cell line. Furthermore, it was demonstrated that H19 was reactivated and demethylated in the HepT1 cell line by 5-azaCytidine, in contrast to IGF2 P3, which was not demethylated or reactivated. We suggest that methylation of the proximal IGF2 P3 is important for its regulation.

Animals↗
PubMed2001

Successful therapy of subcutaneously growing human hepatoblastoma xenografts with topotecan.

BACKGROUND: Human hepatoblastoma is an infrequent liver tumor in children. Although many hepatoblastomas can be treated adequately with well-defined treatment regimens, problems still persist with advanced and non-resectable tumors; in these cases, an effective chemotherapy is necessary to improve the patients' prognosis. This underlines the need for alternative anti-tumor agents in the treatment of human hepatoblastoma. The aim of this study was to investigate the therapeutic effects of topotecan, a water-soluble camptothecin analog (topoisomerase-I-antagonist), in an in vivo model of three human hepatoblastomas xenografted subcutaneously into nude mice. PROCEDURE: Hepatoblastoma cell suspensions from three children were transplanted subcutaneously into nude mice NMRI (nu/nu). Treatment with topotecan was initiated when the tumors reached a volume between 50 and 80 mm(3). A dose of 6.6 mg/kg of topotecan were given intraperitoneally every 4 days on four occasions. The tumor volume development and alpha-fetoprotein alterations were measured and statistically analyzed. After the treatment, the tumors were investigated histologically and by immunohistochemistry. RESULTS: There was a significant reduction of tumor growth in all treated tumor xenografts vs. untreated control groups (mean relative volume 3.1 vs. 47.4; P = 0,0015-0,0079). Serum alpha-fetoprotein levels were reduced in all three cell lines, in two of them significantly (mean 44,535 kU/l vs. 228,883 kU/l; P = 0.005-0.246). Histologically, the tumor necrosis rates were higher and immunohistochemistry showed lower proliferation activities in the treated tumor xenografts vs. the control groups. CONCLUSION: The data show that topotecan is an effective agent in the treatment of human hepatoblastoma xenografts. From these results, treatment with topotecan appears to be a promising alternative in the pre- and postoperative therapy of patients suffering from human hepatoblastoma

Animals↗
PubMed2001

Cortical blindness: an unusual complication after removal of a ganglioneuroma of the neck.

A 5-year-old girl was operated upon after a huge mass had been found on the left side of her neck. Preoperatively the anatomy was studied using MRI, including 3D-reconstruction of the tumor. The left vertebral artery was seen to cross the tumor, and during the operation the vessel was preserved. Postoperatively it thrombosed and a permanent cortical blindness developed. One year later MRI angiography of the intracerebral vessels was performed and a pre-existing anomaly of the circle of Willis was demonstrated, which had contributed to the development of the cortical blindness.

Blindness, Cortical↗
PubMed2001

Promoter-specific transcription of the IGF2 gene: a novel rapid, non-radioactive and highly sensitive protocol for mRNA analysis.

The human insulin-like growth factor-II (IGF2) is a regulatory peptide which is critical in normal fetal growth. IGF2 gene transcription is controlled by the usage of four promoters P1-P4 of which promoters P2-P4 are genomically imprinted. Disruption of imprinting and the resulting increase of gene dosage have been shown to be implicated in tumor progression in a variety of human tumors. Due to the need for high amounts of tissue material for conventional methods such as Northern blotting or ribonuclease protection assay (RPA), studies on IGF2 expression have most often been limited to the detection of total IGF2 transcript, though different dysregulatory events can be responsible for the abundance of IGF2 mRNA found in many tumors. We established a highly sensitive competitive RT-PCR assay for the four different transcripts of the IGF2 gene with transcript-specific external RNA competitors in which we take advantage of fluorescence-based quantification on a semiautomated sequencer. The amount of total RNA needed is approximately 100 times lower than the amounts required for Northern blotting or RPA, so that even cytological samples can be analyzed. We applied the assay to a series of eleven hepatoblastomas (HB) in which normal adjacent liver tissue could also be analyzed.

Child, Preschool↗
PubMed2001

Disseminated choriocarcinoma in infancy is curable by chemotherapy and delayed tumour resection.

Infantile choriocarcinoma has a poor prognosis with only 2 surviving children reported in the literature. 2 additional successfully treated children are presented. 2 infants (age 3 and 4 months at diagnosis) suffering from rapidly progressive choriocarcinoma with widespread haematogenous metastases involving the liver were treated according to the cooperative germ cell tumour treatment protocol (MAKEI 96) of the German Society of Pediatric Oncology and Hematology (GPOH). PEI-chemotherapy (cisplatin, etoposide, ifosfamide; no ifosfamide before the age of 4 months) was combined with delayed tumour resection. Treatment resulted in sustained remission in both children (event-free survival 42 and 40 months). Interphase fluorescent in situ hybridisation (FISH) analysis of the paraffin-embedded tumour sample from case one revealed four to eight copies of chromosomes X, 1 and 17 and two Y chromosomes. Hybridisation with sub-telomere and centromere specific probes for chromosome 1 displayed an imbalance between the short and long arms of chromosome 1. In the tumour cells from case 2, only a polysomy of chromosome X could be proven, other aberrations were not analysed in this case for technical reasons.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed2000

Hepatocyte growth-factor-scatter factor can stimulate post-operative tumor-cell proliferation in childhood hepatoblastoma.

Rapid growth of residual tumor after partial hepatectomy has been observed during the period of liver regeneration in children with malignant embryonal hepatoblastoma. The aim of this study was to elucidate the role of hepatocyte growth-factor-scatter factor (HGF-SF) in this phenomenon. Markedly increased serum levels of HGF-SF up to 15 ng/ml were found in 13/18 patients after liver resection and in 6/16 patients with regressive tumors after chemotherapy, in comparison with 15 patients with non-pre-treated hepatoblastoma and 20 healthy children of the same age group. In the tumors, epithelial tumor cells highly expressed the HGF-SF receptor c-met, as shown by immunohistochemistry and m-RNA RT-PCR. The hepatoblastoma cell lines HepT1, HepT3 and HUH6 reacted with significantly increased proliferation to rhHGF-SF in these concentrations (1-15 ng/ml). In the tumors, HGF-SF was found to be expressed in the stromal fibroblasts. In culture, hepatoblastoma cells (HepT3, HUH6) stimulated secretion of the factor by human fibroblasts, indicating the paracrine fashion of intratumoral HGF-SF production. Cultured hepatoblastoma cells ceased to proliferate at 20-50 ng/ml HGF-SF, and they underwent cell death at >/=100 ng/ml. In contrast, the hepatocellular-carcinoma cell line HepG2 decreased growth under HGF-SF in a dose-dependent manner. We conclude that post-operatively secreted and intratumorally produced HGF-SF can function as a growth factor for hepatoblastoma, while the same agent has a cytostatic effect in unphysiologically high concentrations.

Cell Division↗
PubMed2000

Characterization of genomic alterations in hepatoblastomas. A role for gains on chromosomes 8q and 20 as predictors of poor outcome.

As data on the genomic alterations in hepatoblastoma (HB) are limited, 34 HB tumors and three HB cell lines were screened for DNA copy number changes by comparative genomic hybridization. The average number of chromosomal imbalances per tumor was 2.3 +/- 0.5 (mean +/- SEM) with gains sevenfold more frequent than losses. The most frequent gains of chromosomal material in HB tumors were on 2q (44%), 1q (41%), 2p (29%), 20 (24%), 22q (18%), 8q (15%), 8p and 12q (9% each), as well as 7q, 12p, and 17 (6% each) and the only recurrent loss was on 4q in 12% of cases. Highly amplified sequences were identified in four tumors and mapped to 2q24 in two cases, to 8q in two cases (once to 8q11.2-q13 and once to 8q11.2-q21.3) as well as to 10q24-q26 in one case. In one cell line, highly amplified DNA sequences were mapped to 7p and 8q. Comparison to previously published data on this series of HB revealed that the number of chromosomal imbalances was significantly higher in HB tumors with loss of heterozygosity on 11p (P = 0.03), whereas in five of 10 HB biopsies without chromosomal imbalances, beta-catenin gene mutations were found. HB patients were divided into a good (no evidence of disease) and a poor (died of disease) outcome group according to their clinical course after standard therapy. Two alterations were found to be significantly associated with poor outcome: gain on 8q (P = 0.007) and gain on 20 (P = 0.009). In summary, our analysis allowed the identification of gains on chromosomes 1q and 2 as hallmark DNA copy number changes in HB with 2q24 as a critical chromosomal band. Furthermore, this study provided evidence that gains on 8q and 20 play a role as markers of prognostic significance in HB.

Adolescent↗
PubMed2000

p57(KIP2) is not mutated in hepatoblastoma but shows increased transcriptional activity in a comparative analysis of the three imprinted genes p57(KIP2), IGF2, and H19.

Hepatoblastomas (HBs), representing malignant liver tumors of childhood, show frequent loss of heterozygosity (LOH) in the chromosomal region 11p15.5. This loss is of maternal origin suggesting the presence of a monoallelically expressed tumor suppressor gene in this region. p57(KIP2) (KIP2) located at 11p15.5 is predominantly expressed from the maternal allele and encodes a cyclin-dependent kinase inhibitor. We screened a series of 56 HB tumors and five HB cell lines for allelic loss (LOH) of the KIP2 locus by microsatellite analysis and KIP2 coding sequence mutations by single-strand conformation polymorphism analysis. Although LOH at the KIP2 locus occurred in 25% of the cases, no mutations were found. Analysis of KIP2 mRNA expression by competitive reverse transcriptase-polymerase chain reaction revealed up-regulation in nine of 12 HBs compared to matching liver samples. In contrast, mRNA levels of the putative suppressor gene H19 on 11p15.5 were decreased in 10 of 12 tumors, indicating that KIP2 and H19 are not co-regulated in HBs. IGF2 mRNA expression was increased in 11 of 12 HB samples. All HBs showed monoallelic KIP2 expression. However, the overexpression of KIP2 in HBs with maternal loss of 11p15.5 suggests a reactivation of the paternal allele in these cases. Overexpression of KIP2 in HBs argues against a role as a HB suppressor gene.

Child, Preschool↗