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.

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.

Diagnosis of acute haematogenous osteomyelitis and septic arthritis: 20 years experience at the University Children's Hospital Basel.

OBJECTIVE: To review the diagnostic experience with acute haematogenous osteomyelitis (AHOM) and/or septic arthritis at our institution. METHODS: Retrospective review of the medical records of those patients with a bacteriologically and/or radiologically confirmed diagnosis, hospitalised in the University Children's Hospital Basel, Switzerland between January 1980 and July 2000. RESULTS: 90 patients (61% males), 4 weeks to 14 years of age, met the inclusion criteria. Median duration of disease prior to hospitalisation was 3 days (range 0-14); 88% were admitted during the first week after onset of complaints. 81 patients received no antimicrobial therapy prior to hospitalisation and are the subject of this presentation. ESR (1st hour in mm; median 36; range 11-124), CRP (mg/l; median 64; range 0-221) and WBC (x 10(9)/l; median 13; range 5-34) were elevated in 100%, 82% and 58% of patients, respectively. Blood cultures (BC) and/or tissue cultures (TC) were performed in 79 (98%) patients. Overall, bacteria were isolated from 53 patients (65%) with Staph. aureus as the most frequent organism (n = 31; 50%). BC were performed in 67 patients and yielded 35 (52%) positive cultures; TC (n = 47) yielded 27 (57%) isolates. In 34 patients with both BC and TC performed, only 12 (35%) were positive in both tests. Diagnostic findings were observed in 23 (59%) of 39 plain radiographs, 31 (56%) of 55 sonograms, 39 (89%) of 44 99mTc-labeled bone scans and 4 (100%) of 4 MRI. 41 patients with diagnostic radiological findings had consecutive TC yielding 30 (73%) bacteriological isolates. Median duration of hospitalisation was 15 days (range 2-66). CONCLUSION: Our data indicate that the diagnostic procedures of choice should be 1) early bone scan or MRI, 2) BC and 3) TC. Of supportive laboratory parameters, ESR and CRP were most valuable in our hands.

Effect of sleep, spontaneous gastroesophageal reflux, and a meal on upper esophageal sphincter pressure in normal human volunteers.

Owing to the inherent difficulties of recording upper esophageal sphincter pressure, little is known about normal upper esophageal sphincter physiology. In this study we used a modified sleeve device to record upper esophageal sphincter pressure continuously in 8 normal volunteers. Intraesophageal pH and electroencephalogram activity were also recorded to document the occurrence of spontaneous gastroesophageal reflux and sleep. After an hour of baseline recording, the subjects ate a meal. Recording was then resumed for an additional 7 h during which period the subjects slept part of the time. The mean upper esophageal sphincter pressure was measured for each 10-min epoch. Electroencephalogram recordings were read blindly for the presence and stage of sleep. Periods of sleep were then correlated with the manometric tracings. Mean upper esophageal sphincter pressure during wakefulness, stage 1 sleep, and deeper sleep was 40 +/- 17 (SD), 20 +/- 17, and 8 +/- 3 mmHg, respectively. A significant change in upper esophageal sphincter pressure did not occur postprandially or during episodes of spontaneous gastroesophageal reflux. Upper esophageal sphincter pressure was observed to increase transiently with each inspiration during periods of restfulness and sleep, a response consistent with the hypothesis that one function of the upper esophageal sphincter is to exclude air from the esophagus during respiration. The demonstration that upper esophageal sphincter pressure falls markedly during sleep may have significance in that this diminishes the barrier to nocturnal regurgitation and potential aspiration.