Carol L. Fowler

Percutaneous dilational tracheostomy in children and teenagers

Percutaneous dilational tracheostomy (PDT) is a new technique that has been successfully performed in adult patients who required long-term mechanical ventilation, but it has not been used in children. The authors report their initial experience with PDT in 11 children and teenagers. The procedure is as follows. Using Seldingers technique, the trachea is cannulated with a guide-wire. It is then progressively dilated, to an appropriately sized tract, with dilators from a commercially available kit. Then, a tracheostomy tube can be inserted into the trachea, loaded over a dilator. Eleven children, aged 10 to 20 years, underwent PDT in an average of 20 minutes. In eight cases, PDT was performed at the bedside. One intraoperative and one postoperative complication developed in the same patient; both complications were easily recognized and treated. Tracheal stenosis has not developed in eight decannulated patients at an average of 43 +/- 30 weeks after decannulation. PDT appears to be a safe, potentially cost-effective alternative to open tracheostomy in young patients.

Limy bile syndrome

Limy bile syndrome (LBS) is a rare condition in which a radiopaque gallbladder and/or bile ducts are noted on plain roentgenograms. LBS is caused by calcium carbonate precipitation in the bile and is usually associated with distal biliary tract obstruction. The etiology of limy bile syndrome is unclear; however, it may be a long-term complication of total parenteral nutrition.

Separation of complex pygopagus conjoined twins

Pygopagus twins were born with a unique spectrum of anomalies including a conjoined distal spinal cord, single kidney (in twin A), single rectum (in twin A), single vagina (in twin B), and severe central nervous system anomalies in twin B that precluded her independent survival. Separation at 10 weeks of age was tailored toward Twin As survival. This report discusses the surgical modifications necessary in view of the unique anatomy, including salvaging the distal spinal cord and vagina for twin A.

Metastasis of C1300 and TBJ murine neuroblastomas correlates with expression of matrix metalloproteinases

Because metalloproteinases, specifically type IV collagenases, may mediate metastasis, 72- and 92-kDa collagenase activities were evaluated in two murine neuroblastoma cell lines: non-metastatic C1300 and metastatic TBJ. Zymogram analysis demonstrated that 72- and 92-kDa collagenases were associated only with metastatic TBJ. Three human neuroblastoma cell lines were then evaluated by zymogram and Western blot analyses: 72-kDa collagenase was found in metastatic SK-N-SH and IMR-32, but not in SK-N-MC, which may be a peripheral neuroectodermal tumor and not a neuroblastoma. Therefore, 72- and 92-kDa collagenases may be markers of metastasis in neuroblastoma and may aid in differentiation from other small blue cell tumors.

Combined preoperative and postoperative immunotherapy for murine C1300 neuroblastoma

Preoperative treatment of murine C1300-neuroblastoma (C1300) with triple immunotherapy using low-dose cyclophosphamide (CY), retinyl palmitate (RP), and interleukin-2 (IL2), followed by tumor resection leads to significant initial tumor control and prolonged survival. However, because long-term tumor recurrence is 67%, the efficacy of continued postoperative immunotherapy is now evaluated. Thirty-two A/J mice with 1 cm subcutaneous C1300 tumors were treated for 13 days with CY-100 mg/kg, intraperitoneally (IP), on day 2 of treatment then 25 mg/kg on day 9, RP-2500 IU IP 2 x/week, and IL2 1.6 x 10(5) U IP BID on days 4 to 9 and 11 to 13. On day 14, mice were divided into five treatment groups: (1) OP (operated-tumor resection, n = 6); (2) OP+CY (resection and postoperative CY, n = 7); (3) OP+CY+RP (resection and postoperative CY+RP, n = 7); (4) OP+CY+RP+IL2 (resection and postoperative CY+RP+IL2, n = 7); and (5) CY+RP+IL2 (continued CY+RP+IL2 with no resection, n = 5). Survival and postoperative tumor recurrence were followed for 60 days. The cure rates were group 1 33% (2/6), group 2 43% (3/7), group 3 29% (2/7), group 4 71% (5/7), and group 5 20% (1/5). After surgery, tumors that recurred did so in 8 to 22 days, with no statistical difference noted between groups. MHC class I antigenic expression of tumors resected on day 14 and recurrent tumors was determined with monoclonal antibodies and flow cytometry. In tumors resected on day 14, class I expression measured by mean fluorescence, was 374.8 +/- 27.40.(ABSTRACT TRUNCATED AT 250 WORDS)

Spontaneous Progression of a Stage IV-S Human Neuroblastoma Cell Line Involves the Increased Expression of the Protooncogenes RAS and Eukaryotic Initiation Factor 4E

Until now, there have been no established cell lines of stage IV-S neuroblastoma, a stage of neuroblastoma that can spontaneously regress. We report a newly established and characterized stage IV-S human neuroblastoma cell line (NB-UK-LO, or LO). After four initial passages of this cell line in culture, freezing, then six more passages, spontaneous transformation to a very aggressive phenotype (NB-UK-LP, or LP) was noted with evident alterations in both in vivo and in vitro characteristics. Interestingly, the untreated IV-S tumor in the patient from which the cell line was derived subsequently progressed to a more aggressive (stage IV) neuroblastoma, but it responded favorably to a short course of chemotherapy. In our report, the two cell lines are characterized in regard to in vivo growth in nude mice and molecular expression of MMP-2, MMP-9, N-ras, nm23-Hl, eIF-4E, and CD44.

TBJ murine neuroblastoma resists dibutyryl cyclic AMP-induced differentiation and effects on metalloproteinase secretion

BACKGROUND Nonmetastatic C1300 murine neuroblastoma and TBJ, a metastatic variant, exhibit different mechanisms of metastasis and invasion. METHODS In this study, they were examined for response to 1 mmol/L dibutyryl cyclic AMP in vitro. RESULTS (1) dCAMP induced morphological differentiation in 20% to 40% of C1300 cells, whereas TBJ resisted differentiation. (2) Untreated TBJ expressed 92-kDa metalloproteinase, whereas C1300 expressed none. These results were not affected by dCAMP. (3) Growth curves of untreated C1300 and TBJ were exponential. Dibutyryl CAMP induced a plateau in C1300 growth that was confirmed by increased S-phase cells by cell cycle analysis. CONCLUSIONS TBJ growth was unaffected by dCAMP. Apoptosis, as assayed by Hoechst-merocyanine staining test, was not involved in the growth plateau.

New application of endoloop for rectal polypectomy

The primary difficulty in performing rectal procedures such as polypectomy in children is the limited space in which to suture after a biopsy. Use of an available laparoscopic pretied loop ligature has been adapted to simplify these cases.