Spontaneous pneumomediastinum in a shallow-water--diving child.
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Biomedical subjects
Publications and source records attributed to T V Whalen.
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Although the Worldwide Web has just blossomed this past decade, the origins of the Internet date to the late 1950s and Cold War concerns. The technological underpinning of the Internet rests with the concept of packet switching of data over dispersed routes of electronic intercommunication. Grounded in applications for the national defense, and nurtured in the domains of science within academia, the Internet of the masses has exploded with the addition of strong commercial interest and potential. Electronic mail is still the predominant application of the Internet, and the ease of widespread and near simultaneous dissemination of such communication has led to the genesis of listservers, especially appropriate as well as predominant in Medicine. One such list for pediatric surgeons is Pedsurg-L. There is an impressive evolving etiquette for those contributing to such lists. Initiatives are already well developed with public and private partnerships for the future of the Internet.
BACKGROUND/PURPOSE: The isolated finding of free intraperitoneal fluid on abdominal computed tomography (CT) scan after blunt trauma in adults is considered an indication for laparotomy by many trauma surgeons. The authors wished to determine if these guidelines are applicable to children. METHODS: A retrospective chart review was conducted. The authors included all children (< or =12 years of age) sustaining blunt abdominal trauma who were admitted to our institution between January 1, 1994 and November 1, 1998. RESULTS: There were 814 children admitted, and 437 had abdominal CT scans. Thirty-four studies showed free fluid associated with solid organ injuries, spine or pelvic fractures, or pneumoperitoneum, and were excluded. Thirty-two children had free fluid without associated injuries and formed the basis for the study. Five of these children underwent laparotomy based on the CT finding alone. The remaining 27 were observed with serial abdominal examinations and did not require surgical intervention. Only 1 of the 5 children who underwent surgery for the finding of isolated free fluid had a therapeutic laparotomy. In comparison, during the same period, 38 children underwent laparotomy after blunt injury based only on physical examination findings with a therapeutic laparotomy rate of 68%. The therapeutic laparotomy rate was significantly higher when the procedure was based solely on clinical examination as compared with the isolated finding or free fluid on the abdominal CT (26 of 38 v 1 of 5, P < .05). CONCLUSION: In contrast to adults, finding isolated free fluid on abdominal CT scans in children after blunt trauma does not dictate immediate surgical exploration.
BACKGROUND: The dysregulation of apoptosis may alter the progression of tumor growth and explain the clinical dichotomy observed in children with neuroblastoma (NB). An overexpression of the bcl-2 proto-oncogene induces resistance to apoptosis and has been observed in unfavorable NB. We hypothesized that alterations in apoptosis may be a result of the interactions between NB and the tissues surrounding it. MATERIALS AND METHODS: Human Chang liver cells (HCL, 10(4) cells/cm2) were plated in two-chamber slides for 3 days. Human NB cells (10(5) cells/cm2) were added to one of the chambers and incubated for 3 more days. Control NB were plated under identical conditions in its own medium and in the HCL medium with growth curves measured. DNA fragmentation was detected via the TUNEL method (TdT-mediated nick end-labeling) and bcl-2 expression was determined by immunostaining. RESULTS: NB growth was unaltered by the change in medium. NB stained mildly positive for bcl-2 when plated alone but became markedly positive in coculture. Histologically, HCL and NB appeared healthy when plated alone, but a halo of apoptotic HCL was seen around NB in the coculture. When plated alone, both NB and HCL demonstrated minimal apoptotic activity as detected via the TUNEL method. In the coculture, a halo of HCL surrounding the NB exhibited markedly increased DNA fragmentation and this intensity diminished in cells distant from the NB. CONCLUSIONS: The regulation of apoptosis was altered in this coculture model of NB and HCL. HCL stimulated NB to overexpress bcl-2 and presumably become resistant to apoptosis. Conversely, NB induced the surrounding HCL to undergo apoptosis. The interaction between the local tissue and NB induced alterations in apoptosis in both cell types and resulted in a survival advantage for NB.
An estimated 24 million people, or 11% of the North American population over 16 years of age, use the Internet. An estimated 40% of households have computers, and 37 million people have Internet access. The experience of three pediatric surgery Internet sites are reviewed to evaluate current practices and future potential of the Internet to practicing pediatric surgeons. The sites reviewed are the Pediatric Surgery Bulletin Board System (BBS), the Pediatric Surgery List Server, and the Pediatric Surgery Website. Statistics were collected at each site to characterize the number of users, traffic load, topics of interest, and times of peak use. There are currently 79 subscribers to the Pediatric Surgery BBS and 100 subscribers to the Pediatric Surgery List Server. The average user of the BBS is a young man who has placed an average of 52 calls to the BBS since joining. There have been 1413 Internet electronic mail messages sent. Twenty-five percent of the traffic has been related to clinical problems and 5% to research, teaching, and career issues. Traffic at this site has been increasing exponentially with most of the dialogue concentrated on clinical issues and problem cases. In a 3-month period the Pediatric Surgery Website received 16,270 hits. The most commonly accessed areas include an electronic mail directory, case studies, the job board, information on the pediatric surgical residency, and information on upcoming meetings. Pediatric surgeons are exploring the Internet and using available pediatric surgery resources. The scope of professional information available to pediatric surgeons on the Internet is still limited but is increasing rapidly. The Internet will impact the way physicians practice medicine through education and communication.
Therapy of the lymphomas is predominantly nonoperative, relying on chemotherapy and radiation therapy. In Hodgkin's lymphoma, the role of the surgeon was once large, involving staging laparotomy. At present, chemotherapy is the predominant mode of therapy in patients of all ages, and the therapeutic distinctions centered on the histology of laparotomy specimens no longer exist. The surgeon most often will encounter the patient with lymphoma for biopsy for tissue diagnosis and for institution of long-term venous access. Non-Hodgkin's lymphoma presents with three cellular subtypes in children, and frequently is first seen in the abdomen and mediastinum as a fast-growing diffuse tumor. As a systemic disease, these lymphomas also are nearly always treated systemically by chemotherapy, yet a small number of patients with localized disease may benefit from attempts at tumor extirpation.
Gut ischemia has been implicated in the pathogenesis of necrotizing enterocolitis. Cyclosporine A and rapamycin, both potent novel immunosuppressants which act on signal transduction pathways in CD4+ T-cells, could potentially modulate immune/inflammatory cellular reactions involved in tissue ischemia/reperfusion injury. We hypothesized that cyclosporine A and rapamycin would preserve mucosal cell function and attenuate inflammatory T-cell-mediated cellular changes associated with small bowel ischemic injury. Forty Sprague-Dawley rats underwent 60 min of gut ischemia by vascular occlusion of the superior mesenteric vessels. Animals were randomized to four groups (n = 10): cyclosporine A (CSA, 5 mg/kg/day SQ), rapamycin (RAP, 2 mg/kg/day SQ), cyclosporine A and rapamycin (C&R), and vehicle given to controls (CON). Following 1 hr of reperfusion, small bowel was harvested for xanthine oxidase (XO, units/mg protein) and maltase (MALT, mM substrate degraded/min/g protein) assays. Blood was obtained from the portal vein for tumor necrosis factor-alpha (TNF-alpha, pg/ml) assay. The results of the study are presented below (mean +/- SEM, *, P < 0.05 versus controls). (Table in text) The results indicate that cyclosporine and rapamycin each play a significant role in attenuating ischemia/reperfusion injury in the gut. These data suggest that there are cytoprotective and anti-inflammatory mechanisms of these drugs independent of T-cell signal transduction that provide some protective effect in small bowel ischemia. Furthermore, T-cell-mediated immune mechanisms may not be associated with the adverse effects of small bowel ischemia/reperfusion injury. Additional investigation will be necessary in order to define the role of T-cell-mediated immune injury in the gut and how this relates to the beneficial effect of immunosuppression in small bowel mucosal ischemic injury.
PURPOSE: Gut ischemia has been implicated in the pathogenesis of necrotizing enterocolitis. Cyclosporine A (CSA), a potent immunosuppressant, attenuates immune/inflammatory cellular reactions. CSA also might be useful for inhibiting cellular immune responses involved in tissue ischemia/reperfusion injury. The authors hypothesized that CSA would attenuate inflammatory cellular changes associated with gut ischemic injury and that these effects could be quantified by computerized morphometry. METHODS: Twenty Sprague-Dawley rats underwent 60 minutes of gut ischemia by vascular occlusion of the superior mesenteric vessels. After 1 hour of reperfusion, the ischemic small bowel was harvested for histopathological examination and computerized morphometry, as well as xanthine oxidase (XO, U/mg protein) and maltase (MALT, mmol/L substrate degraded/min/mg protein) assays. CSA (5 mg/kg/d subcutaneously) was given to experimental animals (CSA, n = 10) for 5 days before ischemia, and vehicle was given to controls (CON, n = 10). The computer morphometric parameters studied were: surface index (SI, mucosal surface length per linear unit of intestine), average villous thickness (AVT), and average villous height (AVH). RESULTS: Results are provided in Table 1. CONCLUSION: The results of this study show that CSA may play a role in attenuating ischemia/reperfusion injury in the gut. Enzymatic analysis showed a beneficial role in the preservation of mucosal cell function after gut ischemia/reperfusion injury, as demonstrated by an elevated maltose level. Computerized morphometry demonstrated significant differences in all parameters in the experimental group, showing that CSA does confer gut mucosal protection during ischemia.
INTRODUCTION: A multi-institutional study was conducted by the Children's Cancer Group (CCG) to evaluate all soft tissue sarcomas diagnosed within the first month of life. METHODS: A retrospective study by 11 CCG institutions of patient records from 1971 to 1991 were reviewed for demographic data, pathology, therapy, and outcome. RESULTS: 32 neonates with soft tissue sarcomas were identified. There were 21 boys and 11 girls. Pathology was equally divided into three groups: Congenital fibrosarcoma (CFS) (12), rhabdomyosarcoma (RMS) (11), and non-RMS soft tissue sarcomas (NRSTS) (9). Anatomic sites consisted of head/neck (11), extremity (9), trunk (8), pelvis (3), and unknown (2). Overall survival rate was 59% (19/32). CONCLUSION: Soft tissue sarcomas in the neonate comprise three general groups with survival rates dependent on pathology and extent of disease.
Histopathologic alterations in the intestinal mucosa after ischemic injury have been extensively described in the literature, but these descriptions have primarily been qualitative in nature. The purpose of this study was twofold: (1) to establish parameters obtained by computerized digital image analysis that would be useful in identifying ischemic injury, and (2) to use these parameters to identify the critical period of intestinal ischemia producing measurable histopathologic change. Seventy male Sprague-Dawley rats weighing 80 to 150 g underwent various times of gut ischemic injury by vascular occlusion of the superior mesenteric artery and vein with a microaneurysm clamp. The clamp times were 0, 1, 20, 30, 40, 50, 60, 70, 80, and 90 minutes. Histological sections of the terminal ileum were quantitatively analyzed using Jandel Scientific's computerized morphometric image analysis system. Parameters studied were surface index (SI, surface length per linear unit of mucosa), average villous thickness (AVT), average villous height (AVH), and the number of villous cells/100 microns length (VC). Ischemic times of 1, 20, 30, and 40 minutes produced no measurable injury as compared with baseline (P[40 minutes versus baseline] = SI, .60; AVT, .84; AVH, .93; VC, .09). At 50 minutes, SI and AVH showed a measurable change from baseline (P[50 minutes versus baseline] = SI, .01; AVH, .02). Sixty minutes of ischemic time produced measurable change in all parameters (P[60 minutes versus baseline] = SI, .007; AVT, .001; AVH, .002; VC, .007).(ABSTRACT TRUNCATED AT 250 WORDS)
Hydrostatic reduction of intussusception is definitive therapy in most infants with this abnormality. In the older child, adolescent, and adult, a polyp or tumor is often present. Operative intervention should be considered earlier in the clinical course both to relieve the intussusception and to define the nature of the lead point.
A 14-year-old male was found to have an intussusception secondary to an invaginating Meckel's diverticulum. He was initially referred for crampy abdominal pain and diarrhea, and inflammatory bowel disease was suspected. The etiology of most intussusceptions is unknown; however, both in adolescence and adulthood they may be initiated by a lead point. This paper presents, analyzes, and discusses an intussusception caused by a Meckel's diverticulum as a lead point and the difficulty in making a preoperative diagnosis.
Polysplenia syndrome has been well described. It is associated with gastrointestinal atresia in patients with situs inversus abdominus; however, it appears that this case represents the first occurrence of polysplenia with jejunal atresia having agenesis of the dorsal mesentery and partial situs inversus abdominus.
Recent experience with a twin who had esophageal atresia and tracheoesophageal fistula revealed complex anatomy not suspected before operation. The experience in patients with esophageal atresia and tracheoesophageal fistula who were twins was reviewed at the Children's Hospital of Los Angeles. Of 245 patients seen in the past 23 years, 16 were twins (only two of whom were siblings). Six of the 16 patients (38%) had other than the most frequent anatomy, i.e., proximal atresia of the esophagus and distal fistula. Two of these patients had extremely complex anatomy. Twenty-five per cent of the patients had a right aortic arch compared with 5% of all patients with tracheoesophageal fistula. The surgeon who encounters a twin with esophageal atresia or tracheoesophageal fistula is appropriately cautioned that significant anatomic complexity may be encountered.
From 1941 through 1983, a total of 66 patients with sacrococcygeal teratoma were seen, representing 41 percent of the total of 162 patients with teratomas from all anatomic sites seen over this period. Forty-six (70 percent) of the patients with sacrococcygeal teratomas were female and 34 (52 percent) were neonates. Younger patients had a significantly better prognosis. Approximately half (48 percent) of the patients had benign tumors. Of the other 34 patients, 19 (29 percent) had frank malignancy, being either a purely malignant tumor or a tumor with malignant mixed with benign elements, and 15 (23 percent) patients had tumors containing embryonic but no malignant components. Patients with tumors containing mature adult or embryonic tissues have a good prognosis. However, malignant sacrococcygeal teratoma portends a bleak prognosis irrespective of therapy (in this series only one patient survived among 19 patients with an average survival of 16 months after diagnosis).
Although the etiologies of Hirschsprung's disease and infantile hypertrophic pyloric stenosis remain unclear, it is certain that in Hirschsprung's disease, there is an absence of myenteric ganglia. In pyloric stenosis, there is a decreased number of ganglia, but this may be secondary phenomenon. The occurrence of both Hirschsprung's disease and pyloric stenosis in any single patient is uncommon, disputing a common etiology on statistical grounds. The authors have recently seen two infants with both diseases, and have reviewed the histology and pathophysiology analyzing the possibility of a single cause.
Four cases of pelvic trauma associated with a deep perineal tear are reported. The mechanism of injury, preoperative and operative care of this type of injury are discussed. The theory that the tear is similar to an explosion is presented. Categories of anorectal injury are listed. As expected, genitourinary and rectal injuries as well as hemorrhage are the primary concerns with this type of trauma. Management consists of careful evaluation for genitourinary tract injury followed by careful inspection of the perineal tear in the operating room. Rectal examination is crucial and proctosigmoidoscopy is advised for all injuries. Sepsis is the most important complication of the perineal tear. Prevention begins with mandatory colostomy for all patients. The loop colostomy serves as the necessary totally diverting colostomy. Equally important is evacuation and washout of distal fecal content of colon during operation. Hemorrhage may assume greater importance than with closed injuries due to the loss of tamponade. Hypogastric ligation at the time of exploration and colostomy may be beneficial. Drainage of the pararectal space is necessary when the rectum is directly involved in the tear.