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Biomedical subjects

J B Atkinson

Publications and source records attributed to J B Atkinson.

At least 19 recordsLinked to original sources
PubMed1992

Comparison of cardiac findings in patients with mitral valve prolapse who die suddenly to those who have congestive heart failure from mitral regurgitation and to those with fatal noncardiac conditions.

Sudden death occurs in a small but important subset of patients with mitral valve prolapse (MVP). Clinical criteria for identifying patients at risk for sudden death have been elusive. To determine if certain morphologic characteristics were present in hearts from patients with sudden cardiac death and MVP, autopsy hearts from persons with sudden death and isolated MVP who were previously asymptomatic or had a history of cardiac arrhythmias (n = 27) were compared with (1) hearts from patients with congestive heart failure (CHF) and mitral regurgitation (MR) secondary to MVP (n = 14), and (2) hearts from persons dying from non-cardiac causes in which MVP was an incidental finding (n = 19). Patients who died suddenly were younger than both patients with MR/CHF and incidental cases (37 +/- 10 vs 65 +/- 16 and 58 +/- 21 years, respectively, p less than 0.001). Mitral valve annular circumference, anterior and posterior mitral valve leaflet lengths, posterior mitral valve thickness, and presence and extent of endocardial plaque were greater in hearts from patients with sudden death than hearts from those with incidental MVP. Hearts from patients with MR/CHF weighed significantly more, had greater left and right atrial cavity sizes and left ventricular cavity diameter than hearts from both sudden death and incidental cases.

Age Factors↗
PubMed1992

Preoperative thyroid scanning in presumed thyroglossal duct cysts.

The purpose of this study was to determine if preoperative thyroid scans are essential in the workup of presumed thyroglossal duct cysts. Questionnaires were sent to pediatric otolaryngologists and pediatric general surgeons with a 65% response rate. Fifty-seven percent of the physicians have encountered ectopic thyroid. In 58% of these, this was the only functioning thyroid tissue. Twenty eight percent of pediatric surgeons vs 65% of pediatric otolaryngologists routinely order scans. Two of the physicians encountering ectopic thyroid volunteered that they had successful litigation directed against them for removing the sole functioning thyroid and creating permanent hypothyroidism. There is a likelihood of encountering ectopic thyroid during the course of one's practice. A case of ectopic thyroid is presented, and management strategies are discussed.

Humans↗
PubMed1992

Noninvasive detection of heart transplant rejection with positron emission scintigraphy.

Positron emission tomography has recently been used to evaluate ischemic heart disease through changes in myocardial blood flow and carbohydrate metabolism. Positron-emitting tracers were evaluated for their ability to detect acute allograft rejection after heterotopic cardiac transplantation in the rat. Sham-operated controls, nonrejecting isografts, and rejecting allografts were evaluated. Decay-corrected uptake of 13NH3 and 18F 2-fluoro 2-deoxyglucose (FDG) reflects blood flow and glucose flux, respectively. Histologic examination of rejecting allografts documented mild rejection at 4 days and severe acute rejection by 8 days. All isografts were free from rejection. Uptake of FDG is greater in rejecting allografts than in nonrejecting isografts during both severe rejection (2.4% +/- 0.8% versus 0.7% +/- 0.4%; p less than 0.02) and mild rejection (2.1% +/- 0.6% versus 0.4% +/- 0.1%; p less than 0.02). Uptake of NH3 in severely rejected grafts is reduced compared with nonrejecting grafts (0.6% +/- 0.3% versus 1.7% +/- 1.1%; p less than 0.02). There is no difference in NH3 uptake during mild rejection (1.8% +/- 0.7% versus 1.3% +/- 0.3%; p greater than 0.05). Uptake of FDG and NH3 in native hearts of animals from all experimental groups is not significantly different from that in sham-operated controls. Glucose may be a preferred metabolic substrate during rejection. Our data support a humoral mechanism for substrate preference during transplant rejection and a potential diagnostic role for positron emission tomography.

Ammonia↗
PubMed1992

Persistent pulmonary hypertension complicating cystic adenomatoid malformation in neonates.

Neonates with congenital diaphragmatic hernia (CDH) are known to be susceptible to stress-induced persistent pulmonary hypertension (PPHN). Congenital cystic adenomatoid malformations (CCAMs) may also present as respiratory distress in the newborn. Intubation and mechanical ventilation cause clinical deterioration because of air trapping within cystic spaces; these patients require prompt lobectomy. PPHN has not been commonly associated with CCAM. Three patients with CCAM were encountered who developed PPHN postlobectomy. Three newborns, 36 to 38 weeks' gestation, presented with respiratory distress. Two had diagnosis of thoracic tumors on fetal ultrasound (22 and 33 weeks). Chest x-ray at birth confirmed cystic intrathoracic tumors in all and they underwent immediate thoracotomy and lobectomy (1 right upper, 1 left lower, 1 left upper). The patients were stable for 4 hours to 5 days postoperatively and then developed findings consistent with PPHN by cardiac echocardiography and required extracorporeal membrane oxygen (ECMO) support. ECMO was required for 66.5 to 120 hours. Each patient was successfully weaned to conventional ventilatory support. The clinical course of these patients was similar to those with CDH who undergo immediate surgery. The stress of surgical intervention combined with hypoxia and hypercarbia stimulates a hyperactive pulmonary vasculature and the development of PPHN. ECMO provides an effective adjunct to support patients with PPHN on the basis of congenital cystic adenomatoid malformations.

Cystic Adenomatoid Malformation of Lung, Congenita↗
PubMed1992

Primary endodermal sinus (yolk sac) tumor of the falciform ligament.

Extragonadal yolk sac tumors (YSTs) are uncommon and YSTs of the liver are exceedingly rare, with only three reported cases in the literature. A case is described of primary YST of the falciform ligament extending into the left lobe of the liver in a 14-month-old boy. This is the first reported case of primary YST arising within the falciform ligament. The patient underwent an exploratory laparotomy after presenting with hemoperitoneum. An extremely friable and necrotic tumor was found extending from the falciform ligament into the liver. The tumor was debulked and the patient received 5 months of chemotherapy employing a modified Einhorn regimen. After a partial response to chemotherapy the patient had a second-look laparotomy, at which time a left hepatic lobectomy and en bloc resection of the falciform ligament was performed in order to remove residual tumor. At the present time the patient has no signs of metastases and is alive and well 2 years after his presentation.

Humans↗
PubMed1992

Augmented venous access in the problematic ECMO patient: a case report.

Extracorporeal membrane oxygenation (ECMO) provides an adjunct to support of neonates with respiratory distress. The rate of venous drainage is the limiting step to the amount of arterial flow that may be generated during ECMO. We present a 3-kg, 37-week gestation female with congenital diaphragmatic hernia (CDH) whose anatomic venous drainage was insufficient to allow total extracorporeal support. The internal jugular vein was of insufficient size to allow placement of a cannula large enough to support adequate bypass flow. We established minimally acceptable flow by simultaneous caudad and cephalad catheterization of the internal vein. We performed a right lower quadrant retroperitoneal dissection and cannulated the common iliac vein when systemic pressures deteriorated at 24 hours with marginal venous drainage. After triple cannulation the bypass flows were normal. The right leg developed mild cyanosis and edema immediately following cannulation, but these changes resolved over 24 hours with elevation. The common iliac vein provides a desirable route for augmentation of venous drainage in the patient with difficult standard, or cephalad, jugular venous access for extracorporeal support.

Catheterization, Central Venous↗
PubMed1992

Growth hormone reverses impaired wound healing in protein-malnourished rats treated with corticosteroids.

Corticosteroid (CS) administration amplifies the inhibitory effect of protein malnutrition (PM) on wound healing. Abdominal surgery in protein malnourished patients receiving corticosteroids (eg, advanced malignancy, transplant recipients) may be complicated by wound dehiscence or anastomotic breakdown. Although preoperative parenteral nutrition can reduce the incidence of these complications, this is not possible in patients requiring urgent surgical intervention. In a previous report we demonstrated that postoperative growth hormone (GH) administration could restore normal wound healing in PM rats. This study evaluates the effect of GH on wound healing in PM rats treated with CS. Forty-eight female Sprague-Dawley rats weighing 180 to 210 g were divided into four groups: (1) normally nourished; (2) PM only; (3) PM + CS; and (4) PM + CS + GH. PM rats (groups 2 to 4) received 5.5% protein chow every other day for 8 weeks. Control rats (group 1) received 23.4% protein chow for the same duration. Group 3 and 4 rats received prednisolone (2 mg/kg, intramuscularly) during the last 3 weeks of PM. All animals underwent precise 5-cm midline celiotomies. Postoperatively, rats in all groups were given 23.4% protein chow. Group 3 and 4 rats continued to receive CS postoperatively. Group 4 rats were given GH (0.5 mg/d, intraperitoneally) postoperatively for 5 days. Wound testing was performed on the 6th postoperative day after removal of the sutures. A balloon inserted into the peritoneal cavity through the vagina was gradually inflated. The pressure at which the wound disrupted was recorded as the wound bursting strength.(ABSTRACT TRUNCATED AT 250 WORDS)

Adrenal Cortex Hormones↗
PubMed1992

Proximal and distal cannulation of the internal jugular vein for ECMO in a primate.

Extracorporeal membrane oxygenation (ECMO) is lifesaving for infants with severe respiratory distress but is complicated by severe intracranial hemorrhage in 10% to 30% of patients. Intracranial venous hypertension, as a result of ligation of the internal jugular vein (IJV), has been hypothesized as a contributing factor to cerebral edema and subsequent hemorrhage. Accessory cephalad IJV cannulation may serve as a means of additional venous drainage to the pump as well as protection against intracranial venous hypertension. Proximal and distal cannulation of the IJV were studied in a primate model. The parameters monitored included sagittal sinus, right and left ventricular pressures as well as venous pressure in the ECMO circuit. The cephalad venous cannula was clamped and unclamped at 30-minute intervals. There was no significant difference in sagittal sinus or intracranial pressures during periods of cephalad cannula clamping or unclamping. Venous return was augmented when the cephalad cannula was unclamped. Cephalad cannulation has no demonstrable protective effect on intracranial, subarachnoid or venous pressures but does improve venous return to the ECMO circuit. It is concluded that cephalad venous cannulation is not necessary in all cases and should be reserved for those patients requiring additional venous drainage to support pump flow.

Animals↗
PubMed1992

Major surgical intervention during extracorporeal membrane oxygenation.

Of 135 patients treated with extracorporeal membrane oxygenation (ECMO) between January 1987 and December 1989, 19 (14.0%) patients underwent surgical procedures while on ECMO. Thirteen (68%) patients had operations related to hemorrhage, including cannula site (6), mediastinal (1), hemoperitoneum (3), and hemothorax (3). Six of 13 patients required repetitive operations for bleeding; 4 of 6 died. Six (35%) patients had operations for congenital pathology including patent ductus (PDA) ligation (2), repair of transposition of the great vessels (2), repair of coarctation (1), and repair of congenital diaphragmatic hernia (3). One patient had multiple simultaneous procedures performed. Of these 6 patients, 4 were decannulated immediately and 2 were decannulated within 28 hours following surgery without any bleeding complications. Fifteen of 19 patients were operated on in the neonatal intensive care unit. The 4 remaining patients required transport on ECMO to the surgical suite. Thirteen of the 19 patients requiring surgical intervention on ECMO survived. In the 13 survivors, the mean time to decannulation postoperative was 45 hours, and in those that died it was 90 hours. Our experience suggests that surgical intervention while on ECMO is technically feasible with the best results achieved when rapid discontinuation of ECMO can be accomplished postoperatively. Due to this fact major surgical intervention should be postponed if possible until near the conclusion of the ECMO therapy.

Algorithms↗
PubMed1992

ECMO and the management of congenital diaphragmatic hernia with large diaphragmatic defects requiring a prosthetic patch.

From 1977 to 1991, 136 neonates have had corrective surgery for diaphragmatic hernia at Children's Hospital of Los Angeles. A retrospective study was performed to determine how many of the 136 neonates had defects large enough to require the use of a prosthetic patch to repair the defect. Twelve were found. All 12 were symptomatic at birth for respiratory distress. Mean arterial blood gas values at birth were pH 6.95, PCO2 94.8, and PO2 47.2. The mean oxygen index (n = 10) was 61.8. Six of these patients were repaired without extracorporeal membrane oxygenation (ECMO) support while the other six received ECMO bypass perioperatively. All six of the patients who did not receive ECMO support died despite successful diaphragmatic repair. Five of six patients who received ECMO perioperatively survived (83%). These surviving infants are now between 1 month and 4 years of age. In the survivors, four of five required subsequent repair and patch enlargement for a recurrent diaphragmatic hernia. Gastroesophageal reflux, requiring a Nissen fundoplication in two infants, complicated the course of three survivors. Four survivors were discharged with supplemental oxygen therapy lasting less than 13 months. Patch disruption is predicted to occur at approximately 18 months of age in all patients, especially if little or no muscle was available at primary repair for prosthetic attachment. These children should be followed closely for feeding or respiratory symptoms. Diagnosis of patch disruption can be made by chest x-rays and confirmed by contrast studies. Patch expansion by laparotomy and careful search for additional musculature for patch attachment is recommended when reherniation occurs.

Extracorporeal Membrane Oxygenation↗
PubMed1992

Severe arteriosclerosis in the kidney of a cocaine addict.

Cocaine abuse has been associated with sudden cardiac death with coronary artery thrombosis with or without underlying vessel disease. Additional vascular beds thus far implicated in cocaine-associated arteriopathy include thoracic and abdominal aorta, and pulmonary, cerebral, and placental vessels; abnormalities include vasospasm, thrombosis, and accelerated atherosclerosis. We report the case of an adult male cocaine user with severe arteriosclerosis of renal vessels, and suggest that cocaine may also affect the renal vasculature.

Adult↗
PubMed1992

Congenital diaphragmatic hernia. Stabilization and repair on ECMO.

Availability of extracorporeal membrane oxygenation (ECMO) support and the potential advantages of delayed repair of congenital diaphragmatic hernia (CDH) have led several centers to delay CDH repair, using ECMO support if necessary. This study reviews the combined experience of five ECMO centers with infants who underwent stabilization with ECMO and repair of CDH while still on ECMO. All infants were symptomatic at birth, with a mean arterial oxygen pressure (PaO2) of 34 mmHg on institution of bypass despite maximal ventilatory support. A total of 42 infants were repaired on ECMO, with 18 (43%) surviving. Seven infants had total absence of the diaphragm, and 28 required a prosthetic patch to close the defect. Only five infants ever achieved a best postductal PaO2 over 100 mmHg before institution of ECMO. Prematurity was a significant risk factor, with no infants younger than 37 weeks of age surviving. Significant hemorrhage on bypass was also a hallmark of a poor outcome, with 10 of the 24 nonsurvivors requiring five thoracotomies and six laparotomies to control bleeding, whereas only one survivor required a thoracotomy to control bleeding. In follow-up, nine of the 18 survivors (50%) have developed recurrent herniation and seven (43%) have significant gastroesophageal reflux. Importantly, five of the 18 survivors were in the extremely high-risk group who never achieved a PaO2 over 100 mmHg or an arterial carbon dioxide pressure (PaCO2) less than 40 mmHg before the institution of ECMO. In conclusion, preoperative stabilization with ECMO and repair on bypass may allow some high-risk infants to survive. Surviving infants will require long-term follow-up because many will require secondary operations.

Extracorporeal Membrane Oxygenation↗
PubMed1992

Skeletal muscle composition in dietary obesity-susceptible and dietary obesity-resistant rats.

The intent of this study was to determine whether a relationship exists between susceptibility to high-fat diet (HFD)-induced obesity and skeletal muscle fiber type. Forty-four adult male Wistar rats were given ad libitum access to a HFD (60% of calories from fat) for 4 wk. Rats were then grouped into quartiles for total weight gain, and the top-quartile [obesity prone (OP)] rats were compared with the bottom-quartile [obesity resistant (OR)] rats. OP rats gained 1.5 times as much weight as OR rats. OR rats had a significantly higher proportion of type I muscle fibers in the medial head of the gastrocnemius muscle than OP rats both before (determined from a muscle biopsy) and after the HFD feeding period. A greater proportion of type I fibers may be associated with a greater capacity for fat oxidation, which would favor resistance to body fat accumulation. Preexisting differences in muscle fiber composition may play a role in determining susceptibility to dietary obesity.

Animals↗
PubMed1991

The impact of extracorporeal membrane support in the treatment of congenital diaphragmatic hernia.

Neonates with congenital diaphragmatic hernia (CDH) treated by immediate surgical intervention and conventional ventilatory support have an overall poor survival. The potential of extracorporeal membrane oxygenation (ECMO) therapy to improve survival of infants with CDH remains controversial. Comparison was made in a single institution's pre-ECMO and post-ECMO survival statistics to establish efficacy of extracorporeal support for persistent pulmonary hypertension (PPH). This study was accomplished by stratifying patients by an oxygen index (OI). Sixty-eight patients were treated for CDH from 1977 to 1986 without ECMO. Fifty-eight patients underwent repair of CDH within the first 24 hours of life. Data could be retrieved for calculation of the OI in 46 patients. Nineteen patients developed an OI of 40 or greater; one survived (5%). Three of 27 patients with an OI less than 40 died (OIs = 34, 38, and 38). Thirty-one patients were treated from 1987 to 1989 and none were excluded from ECMO based on a minimum PO2. Fifteen had an OI less than 40 (range, 1 to 38), were treated conventionally, and 13 survived (87%). Sixteen patients had an OI greater than 40 and 13 qualified for ECMO. Nine of 13 survived (69%). Comparing pre-ECMO and post-ECMO survival for infants with an OI of 40 or greater (5% v 69%), there is a significant improvement in survival when ECMO is used (P less than .001). ECMO support offers a strong adjunct in management of neonates with CDH who develop PPH.

Extracorporeal Membrane Oxygenation↗
PubMed1991

The posterior sagittal approach for reconstruction of severe rectovaginal injuries.

Reconstruction of major perineal lacerations in the small child is difficult and frequently results in less-than-satisfactory continence. A 2 1/2-year-old girl who had sustained a fourth-degree perineal laceration at 9 months of age presented with a common rectovaginal orifice and complete fecal incontinence. Repair was carried out via a posterior sagittal approach, resulting in a normal-appearing perineum with complete continence. The techniques used in the posterior sagittal approach allow precise identification of the striated muscle complex and, therefore, offer a valuable means of achieving complete continence. Although the technique was originally described for reconstruction of congenital anomalies, this report demonstrates it to also be useful for reconstruction of severe perineal trauma.

Child, Preschool↗
PubMed1991

Fecal fat, cyclosporine, and alpha 1-antitrypsin for assessment of small bowel function following transplantation.

Many factors affect the integrity of transplanted small bowel. These include ischemic preservation and immunologic injury as well as the division of intestinal lymphatics during transplantation. This study was undertaken to evaluate the recovery of fat absorption in transplanted small bowel in syngeneic rats. Orthotopic transplantation of the total small bowel with resection of the native intestine was performed. The experimental (n = 11) and a pair-fed, sham-operated control (n = 8) groups were fed a 50% kcal corn oil semipurified diet. Studies of cyclosporine (CSA) absorption, maltose absorption, dietary fat, and fecal alpha 1-antitrypsin (FA1AT) excretion in transplanted animals were performed preoperatively and at 15, 30, and 50 days postoperatively. There was no significant difference in the weight change or fat and maltose absorption in experimental animals compared with control animals at any time point. Peak serum CSA levels were lower at day 15 in transplanted animals than in controls (P = 0.006) and improved but remained lower than those in controls at days 30 and 50 (P = 0.017). FA1AT excretion was increased on postoperative day 15 (accompanied by a decrease in body weight) and returned to control levels at days 30 and 50. Transplanted isogeneic rats had weight recovery and fat and carbohydrate absorption similar to those of controls. Transplanted animals had a protein-losing enteropathy measured by FA1AT at day 15 that resolved by 30 and 50 days, respectively. CSA absorption showed a much more gradual return to control levels and remained abnormal at 50 days.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1991

Pulmonary sequestration: diagnosis with color Doppler sonography and a new theory of associated hydrothorax.

The diagnosis of pulmonary sequestration has traditionally relied on angiographic demonstration of a systemic artery to the sequestered lung tissue. Rarely, extralobar sequestration can be associated with tension hydrothorax, which in the past has invariably led to fetal hydrops and death. The authors report the cases of three infants who had initially undergone color and spectral Doppler analysis; in two of them, extralobar sequestrations were associated with congenital hydrothorax. All three patients underwent surgical resection and histopathologic evaluation of their sequestrations. On the basis of the findings, the authors believe that torsion of the sequestration occludes the efferent venous and lymphatic channels, initiating the accumulation of pleural fluid and subsequent hydrops through systemic venous obstruction. Color Doppler made possible the identification of minute feeding vessels, obviating further diagnostic studies.

Bronchopulmonary Sequestration↗