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Biomedical subjects

C M Harmon

Publications and source records attributed to C M Harmon.

35 records · Page 2Linked to original sources
PubMed1999

Specialty networking in pediatric surgery: a paradigm for the future of academic surgery.

OBJECTIVE: To review retrospectively a 4-year experience with pediatric surgical networking at a major academic medical center in the Midwest. BACKGROUND: The growth of managed care in the United States during the past decade has had a major impact on the practice of medicine in general, but especially on academic medicine. In some academic medical centers, the loss of market share has not only affected clinical activity but has also compromised the educational and research missions of these institutions. METHODS: At the authors' institution, a networking strategy in pediatric surgery was established in 1993 and implemented on July 1, 1994. In 1994, one new satellite practice was established; over the next 4 years, four additional practices were added, including one in another state. To assess the impact on financial status, clinical activity, education, and academic productivity, the following parameters were analyzed: gross and net revenue, surgical cases, clinic visits, ranking of the pediatric surgery residency, publications, grant support, and development and endowment funds. RESULTS: Gross and net revenue increased from $3,273,000 and $302,000 in 1993 to $10,087,000 and $2,826,000, respectively, in 1998. Surgical cases and clinic visits increased from 1240 and 3751 in 1993 to 5872 and 11,604, respectively, in 1998. At the medical center's children's hospital, surgical cases and clinic visits increased from 1240 and 3751 to 2592 and 4729 during the same time period. During this 4-year period, the faculty increased from 4 to 11. Since 1997, the National Resident Matching Program has provided data on how pediatric surgery residency candidates ranked a training program. In 1997, this program received the second-most one to five rankings; in 1998, it tied for first. This exceeds the faculty's perception of previous years' rankings. Publications increased from 26 in 1993 to a peak number of 62 in 1996; in 1997 and 1998 the publications were 48 and 37, respectively. External grant support increased from $139,882 in 1993 to a total of $6,109,971 in 1998. Development and endowment funds increased from $103,559 in 1993 to $2,702,2777 in 1998. CONCLUSIONS: Pediatric surgical networking at the authors' institution has had a markedly positive impact on finances, clinical activity, education, and academic productivity during a 4-year period. The residency training program appears to have improved in popularity among candidates, probably because of the increased referral of complex cases to the medical center from the various networking satellites. External grant support and basic laboratory research significantly increased, most likely because of the greater number of faculty with protected time for research recruited. Development and endowment funds dramatically grew because of the excellent fiscal health of the pediatric surgical program. This experience may serve as a model for other academic surgical specialties.

Academic Medical Centers↗
PubMed1998

Changes, with age, in the phospholipid content of the intestinal mucus layer of the newborn rabbit.

BACKGROUND/PURPOSE: The high incidence of bacterial translocation in newborns is thought to be caused, in part, by the immaturity of the intestinal mucosal barrier. Recently, intestinal mucus phospholipids (PL) have been reported to be important factors in the function of this mucosal barrier. The aim of this study was to quantify changes, with age, in the intestinal mucus PL of the newborn rabbit. METHODS: Mucus was gently scraped from the small intestinal mucosal surface of rabbits of different ages (0, 7, 14, and 28 days old and adult; n = 6 for all groups). PL was extracted from the mucus and was separated by two-dimensional thin-layer chromatography. The isolated phospholipid spots were quantified for their phosphorus content. RESULTS: Total PL content of the mucus decreased significantly with age (day 0, 21+/-2; day 7, 16+/-4; day 14, 9+/-3; day 28, 2+/-1; adult, 1+/-1 micromol/g wet mucus; P = .0001). Phosphatidylcholine and phosphatidylethanolamine levels in the adult rabbits were significantly lower in comparison with the 0-, 7-, and 14-day-old pups (P < .05). In contrast, lysophosphatidylcholine and lysophosphatidylethanolamine were significantly higher in the 28-day-old and adult rabbits in comparison with the 0-, 7-, and 14-day-old pups (P < .05). Phosphatidylinositol + phosphatidylserine levels in 7-day-old rabbits was significantly higher compared with adult rabbits. There was no significant difference in the composition of sphingomyeline between groups. CONCLUSION: Significant changes in the content and composition of the intestinal mucus phospholipids were observed during the first month of life in rabbits.

Aging↗
PubMed1998

Immediate and long-term results of surgical management of low imperforate anus in girls.

BACKGROUND: The majority of girls with imperforate anus are reported to have a malformation of the low variety. Despite this, much of the literature has focused on the more complex, high lesions. METHODS: This study reviews our experience with 44 girls with low imperforate anus from a 22-year period. RESULTS: The incidence of associated anomalies was 61%, which is higher than generally reported. All patients in the study had anal fistulae. Fifty-seven percent had perineal fistulae, 23% had fourchette fistulae, and 20% had vestibular fistulae. Cutback anoplasty was performed in 55%, Potts transfer anoplasty was used in 27%, and 18% of patients were treated with either limited posterior sagittal anorectoplasty or anterior sagittal anorectoplasty. Surgical complications were uncommon. Long-term follow-up was carried out by telephone survey. This showed 89% of the girls to be successfully toilet trained. However, 47% of patients experience at least occasional soilage or episodic fecal incontinence. CONCLUSIONS: Low imperforate anus can be successfully treated using a variety of procedures without colostomy. Most girls with low imperforate anus are successfully toilet trained, but problems with continence persist in a significant number of these patients.

Anus, Imperforate↗
PubMed1998

Latex sensitization in general pediatric surgical patients: a call for increased screening of patients.

BACKGROUND/PURPOSE: Latex sensitization is a well-documented occurrence in children with myelodysplastic and urologic anomalies. The incidence of latex allergy in general pediatric surgical patients, however, has not been previously addressed. The purpose of this study was to examine the risk of perioperative latex reactions in a general pediatric surgical practice over a 1-year period. METHODS: This study examined the occurrence of latex sensitization using two methods. First, the preoperative anesthesia records of patients that have undergone surgery from October 1995 through September 1996 at Mott Children's Hospital were reviewed retrospectively. Second, all patients who had intraoperative anaphylaxis attributable to latex sensitization, including those from three additional hospitals, were evaluated. RESULTS: During a 12-month period, 1,523 pediatric general surgical operations were performed at the C.S. Mott Children's Hospital. Of these, only 11 operations on five patients were performed under latex precautions. All of these patients had a preoperative diagnosis of latex sensitivity. During the same period, intraoperative anaphylactic reactions caused by latex allergy occurred in two of the general surgical patients (0.13%) at the C.S. Mott Hospital. Four additional cases are also reported from other study hospitals. None of these patients were suspected, based on current screening methods, of having a latex allergy before their surgery. CONCLUSIONS: Latex allergy is a potentially life-threatening condition in the pediatric general surgical population. Further study is needed to develop criteria to preoperatively identify patients at risk for latex sensitization.

Adolescent↗
PubMed1998

The lateral approach for open splenectomy.

BACKGROUND: Laparoscopic splenectomy (LS) has been used increasingly to treat children with hematologic disorders and has been reported to have advantages over open splenectomy performed through a standard vertical or subcostal incision. The authors perform open splenectomy (OS) through a lateral, muscle-splitting approach, and believe their approach is more reasonable in comparison with LS. METHODS: Thirty-nine consecutive open splenectomies performed between 1991 and 1995 were reviewed retrospectively and compared with recent reports of LS. The series included 24 boys and 15 girls with an average age of 9 years and average weight of 37.5 kg. Indications included immune thrombocytopenic purpura (n = 20), hereditary spherocytosis (n = 18), and sickle cell anemia (n = 1). The operation was performed with the child in the lateral decubitus position through a left upper abdominal muscle-splitting incision (off the 11th rib), sparing the rectus muscle. RESULTS: All 39 cases were completed without intraoperative complications with an average surgical time of 98.0 minutes (range, 30 to 302). The average surgical blood loss was 89 mL (range, 10 to 300). The children started feeding an average of 1.2 days (range, 0 to 4) postoperatively, were on a regular diet at an average of 2.0 days (range, 1 to 6) postoperatively, and had an average length of stay of 2.7 days (range, 1 to 6). There was no mortality or morbidity. CONCLUSIONS: Open lateral splenectomy is performed with shorter surgical times, less blood loss, an excellent cosmetic result, no complications, and a length of stay comparable to any of the published series on laparoscopic splenectomy in children. This approach provides a reasonable basis for comparison with laparoscopic splenectomy.

Adolescent↗
PubMed1997

Conservative management of mesenchymal hamartoma of the liver.

The natural history of mesenchymal hamartoma of the liver is poorly understood. This case demonstrates the course of a biopsy-proven mesenchymal hamartoma using sequential computed tomography (CT) examinations. These CT scans show initial expansion of the lesion with subsequent involution. The spontaneous resolution in this patient suggests the possibility of conservative management of asymptomatic mesenchymal hamartomas. The case is presented, and the literature on mesenchymal hamartoma is reviewed.

Hamartoma↗
PubMed1997

Acute pancreatitis.

The etiology of acute pancreatitis in children is widely varied and includes idiopathic, drug-related, congenital, and posttraumatic causes. Most children have abdominal pain and tenderness without evidence of peritonitis, and most patients will have elevated serum amylase levels initially or after a delay of about 12 hours. If the diagnosis remains equivocal or in the setting of trauma, an abdominal CT scan should be obtained. Initial treatment for all forms of acute pancreatitis includes bowel rest and support with intravenous fluids. A nasogastric tube should only be placed for symptomatic relief and prophylactic broad-spectrum antibiotics should be given only in the setting of necrotizing pancreatitis, especially if patients are receiving pharmacologic immunosuppression. Fever or decline in clinical status should prompt CT scan with intravenous contrast and possible fine needle aspiration to detect the presence of sterile or infected necrotizing pancreatitis. Positive cultures or severely worsening clinical status are indications for necrosectomy and debridement with sequential packing and explorations. All patients who have had an episode of gallstone pancreatitis should have a cholecystectomy after resolution of pancreatic inflammation but before discharge from the hospital.

Abdominal Injuries↗
PubMed1996

Effect of very delayed repair of congenital diaphragmatic hernia on survival and extracorporeal life support use.

BACKGROUND: Since November 1992, operative repair in neonates with congenital diaphragmatic hernia (CDH) at this institution was delayed until respiratory insufficiency had resolved. METHODS: A retrospective analysis was performed (n = 33) comparing delayed repair with our previously reported institutional experience with immediate repair from January 1988 to October 1992 (n = 66). Infants with severe genetic defects or moribund conditions or who were premature were not considered candidates for repair or extracorporeal life support (ECLS), but they were included in the survival analysis. Survival was defined as hospital discharge. Data were compared with an independent t test or Pearson chi-squared test. RESULTS: Mean age at repair was 8.9 +/- 4.5 days (range, 3 to 20 days). Eleven infants in the study group were placed on ECLS (33% versus 68% in the comparison group; p = 0.001). Six of these infants survived (55% versus 58% in the comparison group; p = 0.846). Of these survivors, one patient was repaired while on ECLS, and the remainder underwent repair after decannulation from ECLS. All 20 of the remaining candidates for repair survived without need for ECLS. Overall survival was 79% versus 56% in the comparison group (p = 0.027). CONCLUSIONS: Our current data suggest that very delayed repair of newborns with CDHs is associated with an increase in the overall survival and a decrease in the use of ECLS when compared with previous experience at this institution.

Extracorporeal Membrane Oxygenation↗
PubMed1995

Ovarian torsion: clinical and imaging presentation in children.

Ovarian torsion is uncommon and has a nonspecific clinical presentation. To determine the impact of imaging on clinical management, the authors reviewed their recent experience with 12 children who had a total of 13 episodes of ovarian torsion. Three children presented as neonates, six were premenarchal, and three were postmenarchal. Ultrasound was the imaging study of choice. In all three neonates, ultrasonography showed complex abdominopelvic cysts indicating the need for surgery. In five of 10 episodes in older patients, ultrasonography showed a solid mass with an appearance strongly suggestive of torsion. Same-day surgery was performed in three patients, and the involved ovary was salvaged in one. Another patient had a small piece of normal-appearing ovary left in situ. This low rate of ovarian salvage is attributable to the combination of delay in patient presentation and surgical delay owing to the often nonspecific clinical and imaging presentation of ovarian torsion. A high level of clinical suspicion, expeditious imaging, and familiarity with the varied clinical and imaging presentations of ovarian torsion should decrease the surgical delay and improve the likelihood of ovarian salvage.

Adolescent↗
PubMed1995

Midaortic syndrome and hypertension in childhood.

UNLABELLED: Midaortic syndrome is a form of fibromuscular hyperplasia that involves the abdominal aorta including the renal and visceral branches. Symptomatology depends on the degree and location of vessel narrowing. This report updates the authors' experience and details 17 operative cases, the largest reported series. Seventeen of the 45 patients who have been operated on for severe renovascular hypertension have had this syndrome. Ages have ranged from 5 months to 15 years (average, 9.7 years). Signs and symptoms have included various manifestations of malignant hypertension, congestive heart failure, oliguric renal failure, and claudication. Intestinal angina has not been noted despite celiac and/or superior mesenteric arterial involvement. Although balloon angioplasty was performed in two patients, lasting results were not achieved. One primary nephrectomy was performed. The other 16 patients had vascular reconstructions including aortoaortic bypass grafting (n = 12), with bilateral renal artery bypasses (n = 9) or unilateral renal bypass (n = 3) or bilateral renal bypass alone (n = 4). The majority had associated visceral artery narrowing, but excellent collaterals have been present so no visceral reconstructions have been required. All renal artery bypasses have been with reinforced saphenous vein. RESULTS: In the average follow-up period of 48 months, 12 of the 17 patients have been cured of hypertension, and the other five have improved. Claudication, congestive failure, and renal failure have been alleviated. Thus far, reinforcement of the saphenous vein grafts has prevented aneurysmal degeneration and graft loss. CONCLUSION: These results indicate that aggressive single-stage reconstruction is the best approach for these children.

Adolescent↗
PubMed1993

Binding of sulfosuccinimidyl fatty acids to adipocyte membrane proteins: isolation and amino-terminal sequence of an 88-kD protein implicated in transport of long-chain fatty acids.

We recently reported (Harmon et al., J. Membrane Biol. 124:261-268, 1991) that sulfo-N-succinimidyl derivatives of long-chain fatty acids (SS-FA) specifically inhibited transport of oleate by rat adipocytes. These compounds bound to an 85-90 kD membrane protein which was also labeled by another inhibitor of FA transport [3H]DIDS (4,4'-diisothiocyanostilbene-2-2'-sulfonate). These results indicated that the protein was a strong candidate as the transporter for long-chain fatty acids. In this report we determined that the apparent size of the protein is 88 kD and its isoelectric point is 6.9. We used [3H]SS-oleate (SSO), which specifically labels the 88-kD protein, to isolate it from rat adipocyte plasma membranes. Identification of 15 amino acids at the N-terminus region revealed strong sequence homology with two previously described membrane glycoproteins: CD36, a ubiquitous protein originally identified in platelets and PAS IV, a protein that is enriched in the apical membranes of lipid-secreting mammary cells during lactation. Antibody against PAS IV cross-reacted with the adipocyte protein. This, together with the N-terminal sequence homology, suggested that the adipocyte protein belongs to a family of related intrinsic membrane proteins which include CD36 and PAS IV.

Adipose Tissue↗
PubMed1993

Thoracic trauma in children.

Thoracic trauma in children is an infrequent but potentially lethal injury often associated with coexisting significant injury to other systems. Most reports suggest that the incidence of chest trauma in the injured child is approximately 10%. The most frequently associated trauma is, unfortunately, to the central nervous system and is an unusually deadly combination of injuries. As such, the thoracic injuries serve as a reliable marker for injury severity in children, mandating meticulous evaluation of the child presenting with thoracic trauma. The diagnosis of the thoracic injury may be difficult on cursory clinical examination and supine chest radiograph, and a thorough and focused evaluation of the child's thoracic injuries is required to discover the extent and severity of these injuries. This is particularly important because most of the thoracic injuries that may be immediately life threatening may be expediently and easily treated in the emergency department during the primary survey phase of Advanced Trauma Life Support. But when the injuries are not suspected, diagnosed, and treated, the child's morbidity and mortality risk rises exponentially and approaches 50%. Many current published reports have concentrated on the overall epidemiology of childhood thoracic trauma in order to focus medical attention on the importance of thoracic trauma to medical planning. Much of the remaining pertinent clinical literature on thoracic trauma during the last several years has looked at particular markers of injury severity and on the recognition and management of the rare but morbid cardiovascular and tracheobronchial injuries. Each of these topics is reviewed, with particular attention to the recent literature over the past 12 months.

Blood Vessels↗
PubMed1991

Labeling of adipocyte membranes by sulfo-N-succinimidyl derivatives of long-chain fatty acids: inhibition of fatty acid transport.

Sulfo-N-succinimidyl derivatives of the long-chain fatty acids, oleic and myristic, were synthesized and covalently reacted with isolated rat adipocytes. The plasma membrane proteins labeled by these compounds and the effect of labeling on the transport of long-chain fatty acids were investigated. Sulfo-N-succinimidyl oleate (SSO) and myristate (SSM) inhibited the transport of fatty acids (by about 70%). Inhibition of fatty acid transport was not a result of alterations in cell integrity, as intracellular water volume was not changed. It did not reflect effects on fatty acid metabolism, since it was observed under conditions where greater than 90% of the fatty acid taken up was recovered in the free form. The inhibitory effect was specific to the fatty acid transport system, as the transport of glucose and the permeation of retinoic acid, a substance with structural similarities to long-chain fatty acids, were unaffected. Sulfosuccinimidyl oleate reacted exclusively with a plasma membrane protein with an apparent size of 85 kDa while sulfosuccinimidyl myristate also labeled a 75-kDa protein. These proteins were among the ones labeled by diisothiocyanodisulfonic acid (DIDS) which also inhibits fatty acid transport irreversibly. The data suggest that the 85-kDa protein, which is the only one labeled by all three inhibitors is involved in facilitating membrane permeation of long-chain fatty acids.

4,4'-Diisothiocyanostilbene-2,2'-Disulfonic Acid↗
PubMed1988

Insulin antagonism of catecholamine stimulation of fatty acid transport in the adipocyte. Studies on its mechanism of action.

Insulin at physiological concentrations can suppress catecholamine activation of the membrane transport of long chain fatty acids in the adipocyte. We have previously shown that the stimulatory effect of catecholamines was mediated by a beta-receptor interaction and cAMP (Abumrad, N.A., Park, C.R., and Whitesell, R. R. (1986) J. Biol. Chem. 261, 13082-13086). In this study we have investigated the mechanism of insulin action to antagonize transport activation. Fatty acid transport was stimulated using different cAMP derivatives with varying susceptibilities to hydrolysis by the cAMP-degrading enzyme phosphodiesterase. Insulin was effective in antagonizing the effect of cAMP analogs which were good substrates for the phosphodiesterase and failed to suppress the effect of those which were poorly hydrolyzed by the enzyme. Addition of increasing concentrations (1-100 microM) of the phosphodiesterase inhibitor methylisobutylxanthine (MIX) to norepinephrine (0.1 microgram/ml) gradually abolished insulin's antagonism. Insulin was completely ineffective in inhibiting stimulation by norepinephrine and 20 microM methylisobutylxanthine. Also consistent with involvement of cAMP lowering in insulin action was the finding that adenosine removal greatly diminished insulin's responsiveness. Treatment of cells with adenosine deaminase (1 unit/ml) enhanced the effect of norepinephrine by about 30%. A 10-fold higher range of insulin concentrations was then required to produce inhibition of fatty acid transport. The effect of adenosine removal was reversed by addition of phenylisopropyladenosine (500 nM), which is resistant to hydrolysis by the deaminase. Finally, exposure of insulin-treated cells (1 nM for 5 min) to dinitrophenol (1 mM for 5 min) reversed insulin action, consistent with reports of reversal of insulin's activation of the phosphodiesterase. In conclusion, our studies support the involvement of cAMP lowering in insulin's antagonism of fatty acid transport stimulation in the adipocyte.

1-Methyl-3-isobutylxanthine↗
PubMed1988

Management of children with hypertension from reflux or obstructive nephropathy.

During a ten-year period, 35 children presenting with vesicoureteral reflux, ureteropelvic junction obstruction, or a "small kidney" were found to be hypertensive. Of these, 15 subsequently underwent surgical procedures for relief of hypertension. Seven were "cured," six were "improved," and two were "unchanged." The severity of hypertension could not be correlated with the degree of reflux nor with the degree of obstructive uropathy. However, all children with reflux in our study who were hypertensive had some degree of calicectasis noted preoperatively on intravenous pyelogram. Also it was noted that hypertension may occur several years after successful anti-reflux surgery. Children with vesicoureteral reflux, ureteropelvic junction obstruction, or a small kidney need to have blood pressure determinations at regular intervals, even if all previous readings had been in the normotensive range and whether or not they were followed up medically or post surgically. We suggest that blood pressure determinations be made every three months for the first year after diagnosis of reflux or ureteropelvic junction obstruction, and at least once a year thereafter.

Adolescent↗