[The investigation of blood cells of middle and old age in patients with bronchial asthma and chronic obstructive pulmonary disease by atomic force microscopy. Similarities and differences with the biological animal model].

The investigation of reactive changes of blood cells in such diseases as COPD or asthma in people of different age groups is the very difficult problem. Simulating the same conditions in animals that occur in humans with these diseases can serve as a reliable practical model. It is possible because the changes which take places at the cellular level in animals might reflect a similar trend in the human body.

Total colonic manometry as a guide for surgical management of functional colonic obstruction: Preliminary results.

BACKGROUND/PURPOSE: Functional colonic obstruction (pseudo-obstruction) encompasses a broad group of motility disorders. Medical management of colonic pseudo-obstruction is complex and often fails, leading to surgical referral. In most cases (excepting Hirschsprung's disease) the surgeon is unable to precisely localize the area of functional obstruction. Total colonic manometry can directly measure intraluminal pressures and contractile function along the entire length of the colon. The authors propose that total colonic manometry can be used by the pediatric surgeon to guide the timing and extent of surgical therapy in refractory functional colonic obstruction. METHODS: Four patients were evaluated for functional colonic obstruction. All underwent barium enema and rectal biopsy with a diagnosis of Hirschsprung's disease in one patient. All patients underwent colonoscopy and total colonic manometry. Manometric tracings were obtained while fasting, after feeding, and after pharmacologic stimulation both preoperatively (n = 4) and postoperatively (n = 3). RESULTS: Total colonic manometry identified an abrupt end of normal peristalsis in 2 of the non-Hirschsprung's patients (one in the proximal colon and one in the transverse colon). Medical therapy failed in both of these patients, and they underwent diverting ostomy proximal to the loss of normal peristalsis. The third non-Hirschsprung's patient essentially had normal manometry and was able to have her colon decompressed successfully on a laxative regimen. Repeat manometry after colonic decompression showed return of normal peristalsis in 2 of these patients and continued abnormal peristaltic activity in the third. Definitive surgical intervention based on the results of total colonic manometry was performed on the latter. All 3 patients achieved normal continence. A fourth patient had Hirschsprung's disease confirmed by rectal biopsy and underwent a 1-stage neonatal modified Duhamel procedure, which was complicated by postoperative functional obstruction. Manometry showed a lack of peristaltic function beginning in the right colon. An ileostomy was performed, and timing of ileostomy closure was guided by the return of normal colonic peristalsis seen on manometry. CONCLUSIONS: These initial cases show the utility of total colonic manometry in the management of colonic pseudo-obstruction syndromes. In addition to its diagnostic utility, direct measurement of colonic motor activity can be valuable in deciding the need for and timing of diversion, the extent of resection, and the suitability of the patient for restoring bowel continuity. In Hirschsprung's disease, total colonic manometry can potentially be used to determine suitability for primary neonatal pull-through versus a staged approach. J Pediatr Surg 36:1757-1763.

Mucoepidermoid carcinoma of the thyroid gland: a case report and suggested surgical approach.

Mucoepidermoid carcinoma (MEC) of the thyroid gland is a rare neoplasm with 40 cases reported in the world literature to date. Controversy surrounds the treatment of this rare neoplasm. It has been described as a low-grade indolent tumor that rarely metastasizes and only recurs locally without morbidity. Suggested treatment has consisted of a lobectomy or subtotal thyroidectomy. We report a case of a 63-year-old woman with a 15-year history of a multinodular goiter with a dominant left lobe nodule. Fine-needle aspiration was inconclusive. The patient opted for a total thyroidectomy. Final pathology yielded a diagnosis of mucoepidermoid carcinoma. We propose that despite its low-grade appearance the morbidity and mortality associated with its ability to locally recur and metastasize justify the need for more aggressive surgical therapy.

Comparison of telomerase levels before and after differentiation of two cell lines of human neuroblastoma.

BACKGROUND: Telomerase is the enzyme that is responsible for maintaining telomere length in human germ cells, tumor cells, and immortalized cells. Its specific role in the immortilization process is unknown. This study was performed to determined whether the level of telomerase activity in human neuroblastoma cell lines correlated with their level of differentiation. We proposed that as neuroblastoma cells differentiated into more mature or benign cells, the levels of telomerase expression would decrease. MATERIALS AND METHODS: Two human neuroblastoma cells lines, SK-N-AS and SK-N-DZ, were differentiated using retinoic acid. These cells were assayed for telomerase activity by the telomere repeat amplification protocol (TRAP) before, during, and after treatment with retinoic acid for 8 days. Untreated cells were used for control and were compared to the retinoic acid-treated cells. Differentiation of the cell lines was confirmed by assaying expression of ret mRNA using the reverse-transcriptase polymerase chain reaction (RT-PCR) and gel electrophoresis of the radiolabeled products. RESULTS: No statistical difference in telomerase activity was noted between control and treated groups. CONCLUSIONS: While telomerase activity has been shown by others to correlate with tumor aggressiveness in human neuroblastoma cells, the mechanism that is involved appears to be separate from cellular differentiation.

Effect of the Palmaz balloon-expandable metallic stent in the trachea of pigs.

Endoscopically placed airway stents offer a viable option in primary or adjunctive treatment of severe pediatric tracheobronchial stenoses. Optimistic clinical reports substantiate the need for experimental studies to more effectively evaluate their clinical role. Development of an animal model comparable with the pediatric airway, amenable to endoscopic instrumentation, and capable of assessing effect on growth was the purpose of this pilot project. Nine 4-week-old piglets underwent endoscopic midtracheal placement of the balloon-expandable Palmaz metallic stent. Initial expansion and stent position were verified fluoroscopically and by direct videobronchoscopy. Serial endoscopic examination and stent reexpansion were performed 2 and 4 weeks after stent insertion. Animal weight, clinical tolerance, tracheal growth, and stent integrity were observed. Tracheal inflammation was evaluated grossly and by objective histopathologic criteria. Successful endotracheal stent placement and expansion were accomplished in all piglets. One pig died of anesthesia complications less than 24 hours after stent insertion. The remaining pigs exhibited excellent clinical tolerance through experiment completion. No detrimental effect on growth was noted, and effective dilatation of the stented tracheal region was observed. Stent incorporation was evident with significant mucosal ingrowth. Inflammation in the form of nonobstructing granulation tissue was present, and no evidence of necrosis or cartilage invasion was evident. The piglet trachea appears to be an excellent model for evaluation of expandable metallic airway stents in management of congenital and acquired tracheobronchial stenoses.

Extrauterine twin-twin transfusion affects renal function and perioperative management of conjoined twins.

This series describes the occurrence of unbalanced circulatory shunting in three consecutively treated pairs of conjoined twins. The impact of renal functional changes and compensatory cardiac physiology on the timing of surgery and perioperative management are illustrated. The craniopagus set of twins presented in renal failure (1A) and cardiac failure (1B) to our hospital at age 2.5 years. Renal transplantation for anuria was performed in 1A before separation of the twins. This did not improve urine output in the hypoperfused twin, and normal renal function was not restored until the twins were separated. Two sets of omphalopagus twins were delivered and transferred to our hospital and separated during the first week of life. In each case a preoperative oliguric state in the underperfused twin reversed after separation, and a postoliguric diuresis ensued. Serum creatinine levels were similar in each pair preoperatively despite the inequality in urine volumes. In conjoined twins, assessment of renal function is necessary and should include serial measurements of urine volumes and urine creatinine clearance. Serum creatinine is not a useful marker of individual twin renal function in this situation. When disparity in renal function exists, early separation is indicated to prevent renal failure and compensatory cardiac failure.

The impact of a previous Kasai procedure on liver transplantation for biliary atresia.

The usual treatment for biliary atresia is a Kasai procedure followed by liver transplantation when indicated. Although primary transplantation for biliary atresia without a previous Kasai procedure is occasionally advocated, it is rarely performed. This review was undertaken to evaluate the impact of a Kasai procedure on the morbidity and mortality of patients who went on to need a liver transplant. Sixty-three patients with biliary atresia were included in this review. Fifty seven patients underwent transplantation: eight patients had a liver transplant only (group 1), and 49 patients underwent a Kasai procedure before transplantation (group 2). Six patients died before receiving a transplant. Time spent on the waiting list for liver transplant was longer in group 2 than in group 1 (170.3 +/- 24.6 days versus 63.3 +/- 7.1 days, P < .05). The patients in group 1 were younger (0.7 +/- 0.2 versus 2.3 +/- 0.4 years) and smaller (6.9 +/- 0.4 kg versus 11.6 +/- 1.2 kg) than the patients in group 2 (P = .07). There was no difference in pretransplant urgency status between the two groups. The mean duration of the transplant operation was shorter in group 1 patients (476.8 +/- 53.3 minutes) compared with group 2 (593.9 +/- 29.3 minutes, P = .06). Group 1 patients received 199.8 +/- 46.2 mL/kg blood transfusion intraoperatively, and group 2 patients had twice that amount, 466 +/- 122.5 mL/kg. No patients in group 1 experienced postoperative bowel perforations or required reoperation for bleeding. In group 2 however, 11 of 49 (22.4%) experienced bowel perforations and 7 of 49 (14.2%) required reoperation for bleeding. There was no difference in nonsurgical complications between the two groups. Long-term survival was equal in the 2 groups: six of eight patients (75%) in group 1 and 36 of 49 (74%) in group 2. The marked increase in complications noted in group 2 patients did not reach statistical significance because of the much smaller number of patients in group 1. These results suggest that patients with biliary atresia have fewer complications after transplantation if a Kasai procedure is not performed before the transplant, and that a more careful selection of surgical options available in treating patients with biliary atresia is required.

Laparotomy or drain for perforated necrotizing enterocolitis: who gets what and why?

Between 1974 and 1988, 86 newborns with perforated necrotizing enterocolitis (NEC) were treated by either laparotomy (usually involving a bowel resection and a temporary stoma) or a peritoneal drain under local anesthesia. The survival of babies in the laparotomy group was 57% versus 59% in the drained group. However, for neonates less than 1,000 g survival in the drained group was 69% compared to 22% for the laparotomy group (P <.01). As the weight of the babies increased over 1,000 g, the survival in the laparotomy group increased to 67%. There was no significant increase in survival in infants over 1,500 g. The highest neonatal mortality risk is generally found among babies weighing less than 1,000 g at birth with a gestational age of less than 30 weeks. This risk increases even more when perforated NEC is added to the prematurity. With the use of peritoneal drainage, survival in this group can approach that of larger neonates.

Biliary atresia: should all patients undergo a portoenterostomy?

PURPOSE: The management of noncorrectable extra hepatic biliary atresia includes portoenterostomy, although the results of the surgery are variable. This study was done to develop criteria that could successfully predict the outcome of surgery based on preoperative data, including percutaneous liver biopsy, allowing a more selective approach to the care of these babies. METHODS: The charts and biopsy results of 31 patients who underwent a Kasai procedure for biliary atresia between 1984 and 1994 were reviewed. Values for preoperative albumin, bilirubin, age of patient at Kasai, and lowest postoperative bilirubin were recorded. Surgical success was defined as postoperative bilirubin that returned to normal. A pathologist blinded to the child's eventual outcome graded the pre-Kasai needle liver biopsy results according to duct proliferation, ductal plate lesion, bile in ducts, lobular inflammation, giant cells, syncitial giant cells, focal necrosis, bridging necrosis, hepatocyte ballooning, bile in zone 1, 2, and 3, cholangitis, and end-stage cirrhosis. Clinical outcome was then predicted. RESULTS: Success after portoenterostomy could not reliably be predicted based on gender, age at Kasai, preoperative bilirubin or albumin levels. Histological criteria, however, predicted outcome in 27 of 31 patients (P < .01). Fifteen of 17 clinical successes were correctly predicted; as were 12 of 14 clinical failures (sensitivity, 86%; specificity, 88%). Individually, the presence of syncitial giant cells, lobular inflammation, focal necrosis, bridging necrosis, and cholangitis, were each associated with failure of the portoenterostomy (P < .05). Bile in zone 1 was associated with clinical success of the procedure (P < .05). CONCLUSIONS: Based on the predictive information available in a liver biopsy, we conclude that those patients who will not benefit from a Kasai procedure can be identified preoperatively, and channeled immediately to transplantation.

Primary mediastinal masses. A comparison of adult and pediatric populations.

Since 1944 62 pediatric patients with primary cysts and tumors of the mediastinum have been operated on at our institution. We compared this group with 195 adult patients with similar diagnoses who were operated on during this period. Comparisons were made with regard to histologic type, location, presenting symptoms, physical findings, and surgical complications. We found significant increases in the prevalence of lymphoma in adults (41/195 versus 4/62, p < 0.05) and of neurogenic tumors in children (21/62 versus 24/195, p < 0.05). There were no significant differences in the prevalence of thymic tumors (51/195 versus 22/62), germ cell tumors (24/195 versus 4/62), and cysts (32/195 versus 15/62). There was no difference in the prevalence of symptomatic patients (99/195 versus 36/62). The prevalence of malignancy has increased in both groups since 1970 (2/28 versus 16/34 in children, p < 0.01; and 14/56 versus 69/139 in adults, p < 0.05). This is attributed to a rise in the prevalence of malignant neurogenic tumors in children and to an increase in the prevalence of lymphomas in adults. Tumor size, location, and the presence of symptoms were predictive of malignancy in the adult population but not in the pediatric population. No difference existed in mortality and morbidity between the two groups. All three pediatric deaths were directly related to loss of airway control as a result of mass effect from the tumor. Definite differences exist between the adult and pediatric populations with regard to mediastinal tumors. These differences need to be considered carefully when evaluating and planning treatment for a child with a mediastinal mass.

Perioperative complications of long-term central venous catheters in high-risk patients: predictors versus myths.

A prospective cohort of 126 patients having long-term central venous catheterization was collected over a 10-month period. The patients were preoperatively assessed for the following risk factors: previous catheter placement, an absolute neutrophil count less than 500/mm3, a platelet count less than 50,000/mm3, a BUN value greater than 60 mg/dL or a serum creatinine level greater than 2.5 mg/dL, a prothrombin time greater than 1.5 times control, recent sepsis, and a Western blot test positive for HIV. The incidence of perioperative complications was 23%. Complications included pneumothorax, arterial puncture, tunnel hematoma, unsuccessful initial placement, and reaction to local anesthesia or blood products. No single risk factor had any statistical significance in predicting a complication. In the subpopulation of patients having two or more risk factors, the complication rate was 50%, with the majority of these being failed placement attempts. We conclude that inserting a permanent central venous catheter is not a benign procedure, but it can be safely done in critically ill patients. Furthermore, evaluation of preoperative risk factors in candidates for catheterization can be helpful to the surgeon with respect to counseling and operative planning.

Vascular ring: does magnetic resonance imaging replace angiography?

The records of 21 patients who underwent operation for symptoms attributable to vascular ring were reviewed. The study covered 33 years, 1958 to 1991, and the mean follow-up was 6.8 years. The patients ranged from 7 days to 26 years old with a mean age of 2.9 years. Twenty patients were symptomatic. Symptoms were due to tracheal compression in 16 patients, esophageal compression in 2, and both causes in 2. During the first 30 years, chest roentgenography, barium swallow, and aortography constituted the diagnostic workup in the majority of the patients. During the last 3 years, magnetic resonance imaging replaced aortography. The surgical diagnosis included five variants of vascular ring. The surgical approach consisted of left thoracotomy in 19 patients and right thoracotomy in 2. These 2 had the diagnosis of right aortic arch with posterior left subclavian artery. In both instances, preoperative angiographic data determined the surgical approach. Barium swallow may be sufficient for the diagnosis of vascular ring; however, additional data are useful in determining the surgical approach. Magnetic resonance imaging can yield accurate data without subjecting the patient to the risks associated with angiography.

Preoperative evaluation and general preparation for chest-wall operations.

Chest-wall reconstruction is a major procedure with a risk of life-threatening complications. Accurate preoperative assessment is therefore critical, as it allows detection and treatment of correctable problems and permits the surgeon to individualize postoperative management. Risk factors may be cardiovascular, pulmonary, or nutritional. The guiding principle of planning for the reconstruction is that there must be absolutely no tension at the site of the full-thickness defect in the chest wall.