Biomedical subjects

A G Coran

Publications and source records attributed to A G Coran.

At least 91 records · Page 5Linked to original sources

PubMed1994

Definitive treatment of Hirschsprung's disease in the newborn with a one-stage procedure.

BACKGROUND: The purpose of this study was to review our experience and early follow-up with 15 one-stage pull-through procedures performed at the time of diagnosis in neonates and infants with Hirschsprung's disease. METHODS: Historic chart review of all patients with the new diagnosis of Hirschsprung's disease seen at the C.S. Mott Children's Hospital at the University of Michigan, Ann Arbor, between June 1989 and June 1992 was performed. Progress notes, operative and anesthetic records, pathology reports, and outpatient follow-up notes were used for data collection. RESULTS: Operative technique included a modified endorectal pull-through after determining the presence of ganglion cells by frozen section. No colostomies were performed before or after operation. Three patients had affected family members. All infants were born at term. Operation was performed within 24 hours of diagnosis and as early as 48 hours of age. Twelve patients had standard rectosigmoid disease, two had total colonic disease, and another had long-segment disease. Bowel function returned within 4 days of operation, and feeding was instituted by postoperative day 6 in all patients. All of the patients with rectosigmoid disease are doing well. Patients with long-segment or total colonic disease had more problems but are currently at home and doing well. Morbidity included two postoperative bowel obstructions and three patients with postoperative enterocolitis. CONCLUSIONS: A single definitive operation may be used to treat Hirschsprung's disease diagnosed in the newborn. Long-term follow-up in these patients is required.

Female↗

PubMed1993

Prenatal diagnosis of gastrointestinal obstruction: a correlation between prenatal ultrasonic findings and postnatal operative findings.

The impact of prenatal sonographic diagnosis of oesophageal and gastrointestinal obstructions has been analysed over a 10-year period. Three groups of patients were evaluated. The first group consisted of 46 newborns with abnormal prenatal sonograms, 41 of which were confirmed to have intestinal obstruction postnatally. The second group consisted of 17 neonates with normal prenatal sonograms who had intestinal obstruction postnatally. The third group included 56 newborns who did not undergo a prenatal sonogram but who had intestinal obstruction confirmed at surgery. Polyhydramnios without the appearance of a stomach on ultrasound was diagnostic of pure oesophageal atresia. Polyhydramnios with intestinal dilation was diagnostic of intestinal obstruction. Although surgery was performed earlier in the infants diagnosed prenatally with ultrasound, mortality was no less than in the group that did not undergo a prenatal sonogram, probably because of the high incidence of associated anomalies.

Esophageal Diseases↗

PubMed1993

Decreased oxidized glutathione with aerosolized cyclosporine delivery.

Cyclosporine immunosuppression remains vital for successful lung transplantation. Cyclosporine also functions as a membrane active biological response modifier and has been noted to have a variable effect on ischemia-reperfusion (I/R) injury in various tissues. Glutathione plays an important role in the endogenous antioxidant defense system; plasma oxidized glutathione (GSSG) levels are useful as a sensitive indicator of in vivo oxidant stress and I/R injury. Lung transplantation results in ischemia, followed by a period of reperfusion, potentially producing functional injury. This study was designed to evaluate the effect of cyclosporine on oxygen radical generation in a model of single-lung transplantation. Single-lung transplantation was performed in 12 mongrel puppies, with animals assigned to receive either intravenous or aerosolized cyclosporine. Arterial blood and bronchoalveolar lavage fluid (BALF) samples were obtained to determine GSSG levels via a spectrophotometric technique. Samples were obtained both prior to and following the revascularization of the transplanted lung. Whole blood and tissue cyclosporine levels were determined via an high-performance liquid chromatography technique 3 hr following the completion of the transplant. Aerosolized cyclosporine administration resulted in greatly decreased arterial plasma and BALF GSSG levels, whole blood cyclosporine levels, and equivalent tissue cyclosporine levels when compared to intravenous cyclosporine delivery. These findings support the hypothesis that the transplanted lung is a source of GSSG production and release into plasma. Additionally, these findings suggest that cyclosporine may have a direct antioxidant effect on pulmonary tissue, with this activity occurring at the epithelial surface, an area susceptible to oxidant injury.

Aerosols↗

PubMed1993

Lung injury produced by moderate lung overinflation in rats.

In models using both intact animals and isolated lungs of rats, rabbits, lambs, and dogs, application of high airway pressure and resultant lung overdistension has been shown to cause lung injury. Under pathological conditions, the more normal portions of the lung may be subjected to relative overdistension when supranormal airway pressures are used. A small animal model of lung overdistension is presented here to demonstrate that lung injury can be caused by moderate lung overdistension. Rats were anesthetized with Ketamine and pentobarbital. A tracheostomy was performed and arterial and central venous catheters placed. The animal was placed in a plethysmograph and an infant ventilator was used to provide mechanical ventilation. In the first experiment, animals in group A (n = 6, control) were ventilated at tidal volume (TV) of 5 mL/kg for 5 hours. Animals in group B (n = 6) were ventilated at TV 15 mL/kg for 60 minutes and then were returned TV of 5 mL/kg for the remainder of the experiment. Animals in group C (n = 5) were ventilated at TV 20 mL/kg for 60 minutes and then returned to TV 5 mL/kg. Static lung compliance and arterial blood gasses were measured. Wet and dry lung weight were obtained after sacrifice. In the second experiment, animals in group D (n = 4, control) were ventilated at TV 5 mL/kg for 240 minutes and killed. Animals in group E (n = 4) were ventilated at TV 20 mL/kg for 60 minutes, returned to TV 5 mL/kg, and killed at 240 minutes. Fluorescein-labeled albumin was administered to each animal prior to mechanical ventilation.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

PubMed1993

Trauma scores, accident deformity codes, and car restraints in children.

The importance and effectiveness of the appropriate use of automobile restraints by young children has been emphasized in several studies. Once the child has entered the emergency care system, however, restraint use may not be the best predictor of injury severity. This study was undertaken to investigate the relationship of restraint status to morbidity and mortality in children examined in a hospital emergency facility following involvement in a motor vehicle crash (MVC). The emergency room charts of 101 children under 18 years of age, who were victims of MVCs, were reviewed and the following trauma scores were calculated: Glascow Coma Scale, Pediatric Trauma Score, Revised Trauma Score, Injury Severity Score, and Maximum Abbreviated Injury Score. In addition, the Traffic Accident Damage (TAD) score, an estimate of crash severity determined by the police at the accident scene, was recorded. The patients were age stratified as follows: 0 to 4 years (n = 24), 5 to 11 years (n = 29), and 12 to 17 years (n = 48). Fifty patients were appropriately restrained at the time of the crash. There was a significant correlation between mean trauma scores and mean TAD codes (P < .05). There were no significant differences in mean trauma scores between improperly restrained (n = 11) and unrestrained (n = 40) children (P > .05) across all age groups, and these children were grouped together as "unrestrained" in further analyses.(ABSTRACT TRUNCATED AT 250 WORDS)

Accidents, Traffic↗

PubMed1993

Reperfusion injury following single-lung transplantation: the tissue glutathione response.

Parenchymal injury following reperfusion of the donor lung remains a significant problem in clinical lung transplantation. It has been postulated that free oxygen radicals act as local mediators of this event, and that tissue oxidized glutathione levels which reflect local free oxygen radical production, may be useful as an indicator of this regional ischemia-reperfusion injury. The glutathione redox cycle plays a physiologically important role in the endogenous antioxidant defense system. Intracellular glutathione depletion has been shown to render cells vulnerable to oxidant mediated injury. Adequate glutathione stores may be vital in protecting the cell from oxidant injury, especially the relatively exposed pulmonary epithelial cells. Single lung transplantation was carried out in 10 3- to 5-kg mongrel puppies, with a standard 2-hour ischemic time for the donor lung prior to reimplantation. Four hours following transplantation, lung tissue was harvested from both the transplanted and native lung of the recipient animal, and compared to normal lung tissue from the donor animal. Tissue was prepared for histological evaluation and glutathione assay. Tissue glutathione levels were determined via a spectrophotometric assay. For determination of oxidized glutathione (GSSG), samples were prepared with 2-vinylpyridine and N-ethylmaleimide (NEM) to derivatize all reduced glutathione and leave only GSSG for measurement by the fluorometric assay.(ABSTRACT TRUNCATED AT 250 WORDS)

Analysis of Variance↗

PubMed1993

Efficacy of the Nissen fundoplication in the management of gastroesophageal reflux following esophageal atresia repair.

From January 1974 to December 1988, 80 patients with esophageal atresia (EA) and tracheoesophageal fistula (TEF) were treated at the C.S. Mott Children's Hospital with division of their TEF and esophagoesophagostomy. Thirty-four in this group developed gastroesophageal reflux (GER). After an unsuccessful trial of medical management, 21 underwent Nissen fundoplication, and an additional child with refractory GER died intraoperatively before completion of her fundoplication. Following fundoplication, only eight patients had an uncomplicated course with elimination of reflux and no postoperative dysphagia. Wrap disruption and recurrent reflux occurred in 7 of the 21 (33%), a markedly higher incidence than the 10% figure seen in 220 children without EA who have undergone fundoplication at this institution. Upward tension on the wrap due to the presence of a shortened esophagus probably predisposes to an increased frequency of fundoplication failure in the EA child. In addition, postoperative dysphagia requiring prolonged gastrostomy feedings complicated eight otherwise successful initial or redo-fundoplications. Prolonged dysphagia in this group is likely related to the inability of the dyskinetic esophagus, common in EA, to overcome the increased resistance caused by the Nissen fundoplication. Three deaths (14%) from complications related to antireflux surgery occurred in the series. Although 15 of the 21 children (71%) eventually had excellent long-term results following initial or redo-fundoplication with elimination of reflux and normalization of oral intake, morbidity and mortality were clearly significant. Due to the high incidence of postoperative dysphagia and recurrent reflux, the transabdominal Nissen fundoplication may not be appropriate in EA patients.

Child↗

PubMed1993

Effects of coenzyme Q10 on the mediator cascade of sepsis.

Coenzyme Q10 (CoQ) has been promoted as an effective agent for reducing the deleterious effects of septic shock by acting as an oxygen free radical scavenger and thus stabilizing mitochondrial membranes and by inhibiting the arachidonic acid metabolic pathway and the formation of various prostaglandins. This study was undertaken to evaluate the effect of CoQ in a live Escherichia coli model of canine septic shock. Group I (E. coli, n = 5) animals received an LD100 dose of 10(9) live E. coli/kg and were given no further treatment. Group II (CoQ, n = 5) animals received a 20-mg/kg bolus of CoQ without further treatment. Group III (CoQ + E. coli, n = 5) animals received a 20-mg/kg bolus of CoQ 10 min prior to a bacterial infusion as in group 1. Mean arterial pressure stabilized at 70% of baseline levels (P < .002), while cardiac output remained near 50% of baseline levels (P < .053) in group III compared to group I dogs. The arachidonic acid metabolites, prostaglandin E2, Thromboxane B2, and leukotriene B4 were significantly elevated in groups I and III (vs. group II) (P < 0.05). The catecholamines, tumor necrosis factor (TNF) and interleukin 6 (IL-6) were significantly elevated in groups I and III (vs. group II) (P < 0.05). Fluorescent products (lipid peroxidation activity) were elevated in group I (vs. groups II and III) at 120 and 180 min (P < 0.05). We conclude that CoQ supports cardiovascular hemodynamics and prevents free radical mediated lipid peroxidation during live E. coli septic shock, and its effect is not due to altered levels of humoral or cytokine mediators.

Animals↗

PubMed1992

Intestinal vaginoplasty for congenital absence of the vagina.

Congenital absence of the vagina is rare and occurs as a result of aplasia of the Müllerian ducts (46,XX) or complete androgen insensitivity syndrome (AIS--46,XY). Both syndromes are associated with normal female external genitalia and these patients are raised as females. These children are usually treated during adolescence with chronic dilatation of the shallow vaginal introitus (pressure tube technique) or by skin graft vaginoplasty (McIndoe procedure). Neither of these procedures is entirely satisfactory, as both may lead to neovaginal stenosis, inadequate length, poor lubrication, or all three. We have recently modified the operation first described by Baldwin in which a loop of sigmoid colon or small bowel is isolated, closed at one end, and brought down on its vascular pedicle as a neovagina and anastomosed to the hymenal ring. We have performed this operation on four adolescents (mean age, 15 years) and two infants (aged 4 days and 14 months) with excellent results (mean follow-up, 7.5 years for the adolescents and 1.8 years for the infants).(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗

PubMed1992

Hypoxia-induced bacterial translocation in the puppy.

Because hypoxia is one of the most common major stresses to which a neonate is exposed, we postulated that it alone might be the cause of intestinal bacterial translocation, which could be the underlying etiology of neonatal sepsis. An animal model, in which hypoxia is the sole stress, was developed in our laboratory and tested in 18 puppies to determine the effect of hypoxia and reoxygenation on intestinal bacterial translocation. In group I (n = 8), following laparotomy and cannulation of the superior mesenteric vein (SMV), the FIO2 was decreased from 21% to 9% for 90 minutes followed by reoxygenation at 21% for 120 minutes. The abdomen was closed and the animals were allowed to recover. After 24 hours the mesenteric lymph nodes (MLNs), spleen, and liver were harvested for bacterial determination and the ileum and jejunum for histological evaluation. Group II (n = 7) was treated the same as group I with the FIO2 maintained at 21%. Group III (n = 3) animals were killed, without intervention, for bacterial analysis. In group I, the systemic PO2 decreased by 75%, SMV PO2 decreased by 64%, and oxygen delivery to the small bowel decreased by 80% in comparison with group II. The mean arterial pressure and cardiac output were not significantly different between group I and group II; however, the mucosal blood flow was decreased by 60% (P less than .001) in group I. Arterial and SMV blood lactic acid levels were unchanged in group I in comparison with group II, suggesting that anaerobic metabolism was not initiated in the splanchnic circulation during hypoxia.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

PubMed1992

Extracellular fluid and total body water changes in neonates undergoing extracorporeal membrane oxygenation.

After being placed on extracorporeal life support (ECLS), newborn patients typically weight 5% to 30% more than their birthweight. Recovery and eventual decannulation from ECLS is associated with a return to baseline weight or birthweight values after a pronounced diuresis. It has been assumed that the increases in weight in these patients are due to increases in extracellular fluid (ECF) and total body water (TBW). This study was undertaken to prove or disprove this hypothesis. ECF space was measured using the compound sodium bromide and TBW was determined with the use of deuterium oxide (nonradioactive heavy water). Fluid compartment measurements were made prior to the institution of ECLS, immediately after placement on bypass, approximately every other day while on bypass, and a final measurement was made once the patient was off bypass. Sodium bromide concentration was analyzed by high-pressure liquid chromatography, and deuterium oxide concentration was measured by the falling drop method. Eight newborns with respiratory failure were placed on either venoarterial (4 patients) or venovenous (4 patients) ECLS for an average of 106 hours (range, 71 to 219 hours). Pre-ECLS TBW was high in the neonates (87% of total body weight v the normal of 75% to 80%). Mean values for each fluid compartment were corrected for the additional volume of the bypass circuit when the patient was on bypass. ECF increased immediately after the institution of ECLS; however, both ECF and TBW decreased during the bypass run, and post-ECLS levels of ECF and TBW were similar to those found prior to ECLS.(ABSTRACT TRUNCATED AT 250 WORDS)

Body Water↗

PubMed1992

Pericardial flap interposition for the definitive management of recurrent tracheoesophageal fistula.

From 1974 to 1988, six children with fistula recurrence following primary tracheoesophageal fistula (TEF) repair have been managed at our hospital. Reclosure of the fistula with pleural flap interposition was used as the initial corrective procedure in five patients, with an 80% incidence of second TEF recurrences. Due to these discouraging results, we have abandoned this technique and instead favor fistula reclosure with interposition of a pedicle of vascularized pericardium between the esophageal and tracheal suture lines. The pericardial pedicle is easy to mobilize, effectively isolates the tracheal and esophageal suture lines, and eliminates the often difficult task of finding sufficient pleural tissue for fistula interposition in small infants. Furthermore, the vascularized pedicle serves as a template for the ingrowth of neomucosa from the existing esophageal mucosa should an anastomotic leak occur. Since adopting this approach, we have used this technique on four children, three of whom had second recurrences after pleural interposition, and have had no evidence of recurrent fistula formation at follow-up ranging from 2 to 6 years. With at least a 20% incidence of second recurrences reported following conventional management with fistula closure and pleural interposition, we believe use of a pericardial flap in the management of the recurrent TEF is the most appropriate surgical procedure.

Humans↗

PubMed1992

Ibuprofen intervention in canine septic shock: reduction of pathophysiology without decreased cytokines.

This study was undertaken to evaluate the effect of a cyclooxygenase inhibitor, ibuprofen, at various time intervals in a live Escherichia coli model of canine septic shock. Group I (control) animals (n = 5) received a LD100 dose of 10(9) live E. coli per kilogram were given no further treatment. Group II animals (n = 5) received a 10 mg/kg bolus of ibuprofen 10 min prior to bacterial infusion. Group III animals (n = 5) received ibuprofen 15 min after the bacterial infusion. Statistical analysis revealed the following: Group II animals had significantly higher MABP and significantly lower levels of serum fluorescent products (superoxide radical activity), plasma thromboxane B2, prostaglandin E2, and endotoxin levels compared to Group I animals (P less than 0.05). Plasma levels of tumor necrosis factor (TNF) and interleukin-6 (IL-6) were significantly elevated (P less than 0.05) from baseline in all animals (Groups I, II, and III), but ibuprofen treatment failed to either increase or decrease these levels. This study demonstrates that ibuprofen treatment can significantly reverse the deleterious hemodynamic and metabolic effects commonly seen in live E. coli septic shock without depressing the endogenous production of TNF or IL-6. These data support the hypothesis that sepsis initiates a cascade of mediators with the cytokines TNF and IL-6 being proximal events which in turn stimulate the next level, with ibuprofen probably exerting its inhibitory effect distal to this point in the cascade.

Animals↗

PubMed1992

Appendiceal transection in a child associated with a lap belt restraint: case report.

The seatbelt syndrome refers to the spectrum of injuries associated with lap belt restraints and includes intestinal tears, perforations, and transections; mesenteric disruptions; and lumbar distractions, dislocations, and fractures. We report a case of appendiceal transection associated with a lap belt restraint in a small child.

Accidents, Traffic↗

PubMed1992

Intravenous nutrition for the pediatric patient.

Nutritional management of infants and children differs from that of adults because of the extra requirements for growth and the limitations of physiological immaturity. Although parenteral nutrition (PN) is an accepted practice and a potentially life-saving therapy for pediatric patients who cannot be fed through their gastrointestinal tract, it is associated with the risk of serious metabolic, mechanical, and infectious complications. Candidates for PN should be selected according to well-defined indications, with initial nutritional assessment and with careful attention given to fluid, electrolyte, vitamin, trace element, and caloric requirements. Total calories should be administered so that the nonprotein-calorie to gram-nitrogen ratio is in the range of 150 to 250:1. Although short-term supplemental nutritional support can be administered through a peripheral vein, long-term total PN is best delivered by central venous access. PN should be initiated and monitored in accordance with well-established protocols. The lowest complication rate and highest cost-effectiveness are achieved by an interdisciplinary team that includes one or more nurses, dietitians, pharmacists, and physicians. The development of safe, reliable, and miniaturized intravenous pumps with built-in monitors has made home parenteral nutrition possible and desirable in selected patients.

Catheterization, Central Venous↗

PubMed1992

Etiology and management of respiratory complications after repair of esophageal atresia with tracheoesophageal fistula.

This article reviews the cause and management of respiratory symptoms after repair of esophageal atresia with tracheoesophageal fistula (TEF). Postoperative respiratory symptoms developed in 31 (46%) of 68 patients and included apnea and bradycardia, respiratory arrest, aspiration, and recurrent pneumonia. The respiratory symptoms were initially attributed to gastroesophageal reflux (GER) in 20 patients (64%), tracheomalacia in 4 patients (13%), recurrent TEF in 4 patients (13%), and anastomotic stricture in 3 patients (10%). Three patients with GER and the three patients with a stricture were initially managed nonoperatively. The remaining 25 patients underwent surgical correction of the underlying cause of the respiratory symptoms. Despite aggressive management of this problem, 14 (45%) of these 31 patients had persistent or recurrent respiratory symptoms. Although GER is the most common cause of respiratory complications in patients who have undergone prior TEF repair, other factors are often responsible for these symptoms and should not be overlooked.

Esophageal Atresia↗

PubMed1991

Redo fundoplication in infants and children with recurrent gastroesophageal reflux.

The Nissen fundoplication is well established as the surgical treatment for medically refractory gastroesophageal reflux (GER) in childhood. Recurrent GER following fundoplication is a challenging problem with a reported incidence ranging from 0% to 12%. From January 1974 to January 1989, 286 children have been treated for GER with Nissen fundoplication and gastrostomy tube placement at the University of Michigan C.S. Mott Children's Hospital; 242 of these children have been followed for an average of 30 months, the remaining 44 have been lost to follow-up. Twenty-nine children (12%) have developed recurrent reflux following fundoplication. Medical management with thickened upright feelings, gastrostomy feedings, or gastrojejunostomy tube feedings has been successful for 11 children with control of reflux symptoms. Five additional children who were treated nonoperatively died of coexistant medical problems within 2 months following documentation or recurrent reflux. The remaining 13 children have required redo fundoplication for wrap disruption or herniation, and an additional six children, initially treated at other institutions, have also undergone redo fundoplications. One other child treated at this hospital required redo fundoplication for a postoperative partial gastric volvulus causing gastric outlet obstruction. Of the 20 children who have undergone a second Nissen fundoplication, 16 (80%) are doing well without recurrent GER. Four children have developed recurrent GER with wrap disruption; 1 is doing well following a third fundoplication, 2 have been managed successfully with continuous feedings via gastrojejunostomy feeding tubes, and a fourth child died of complications related to a recurrent tracheoesophageal fistula. Conservative management with gastrojejunal tube feedings should be considered in the initial management of children with recurrent GER following fundoplication.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗

PubMed1991

Surgical management of ambiguous genitalia in the infant and child.

Proper gender assignment to a neonate born with ambiguous genitalia is a social emergency of the newborn period. Once an appropriate sex assignment has been made, the next critical step is performance, if needed, of a reconstructive procedure in a timely fashion. In an attempt to evaluate our experience with this unique group of patients, we have retrospectively reviewed the course of 69 children with ambiguous genitalia managed surgically at this institution between 1974 and 1989. This series consists of 32 genotypic females with congenital adrenal hyperplasia (CAH), 10 children with mixed gonadal dysgenesis (MGD), 10 male pseudohermaphrodites, 3 true hermaphrodites, 8 genotypic females with urogenital sinus anomalies (UGS), and 6 genotypic males with bilateral undescended testes and penoscrotal hypospadius. All newborns initially seen at this institution received proper sex assignment within the first week of life. Prior to 1980, 17 of the children with CAH underwent clitorectomy and vaginoplasty and three underwent clitoral recession and vaginoplasty. After 1980, 10 patients with CAH were managed with clitoral recession and vaginoplasty and 2 with vaginoplasty alone. Eight of 10 cases of MGD were given a female sex assignment and all 8 underwent gonadectomy due to the high risk of gonadoblastoma; the other 2 children were raised as males. There were 3 true hermaphrodites of which 2 were assigned female gender roles and were managed with a clitoral recession and vaginoplasty. All 10 male pseudohermaphrodites were raised as females and all underwent bilateral orchidectomy. The 8 children with UGS were raised as females and underwent vaginal reconstruction.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗