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Biomedical subjects

C J Stolar

Publications and source records attributed to C J Stolar.

At least 55 records · Page 3Linked to original sources
PubMed1989

Similar efficacy of 6 and 18 months of therapy with four drugs (COMP) for localized non-Hodgkin's lymphoma of children: a report from the Childrens Cancer Study Group.

Successful treatment of localized non-Hodgkin's lymphoma (NHL) in childhood with 18 months of cyclophosphamide, vincristine, methotrexate (MTX), and prednisone (COMP) prompted a randomized clinical trial to determine whether a 6-month course of the same therapy was as effective as an 18-month course when combined with local irradiation. Two successive Childrens Cancer Study Group (CCSG) protocols (CCG 551 and CCG 501) entered 232 eligible patients from October 1979 until April 1986. Initially, all children with localized disease were considered eligible, but by a subsequent amendment, those with lymphoblastic (LB) histology were excluded. Hence, the study population consisted of 211 patients with nonlymphoblastic (NLB) and 21 with LB disease. Early relapses (before 6 months) occurred in 13 patients with NLB histology. Late relapses were seen in seven patients, three with LB histology. Among the 104 randomized patients who followed the prescribed therapy, there were four recurrences and no differences between 6-month and 18-month therapy. The overall survival for NLB disease was 91% on CCG 551 and 98% on CCG 501. We conclude that 6 months of COMP is excellent therapy for children with localized NLB NHL.

Adolescent↗
PubMed1988

Extracorporeal membrane oxygenation causes significant changes in intracranial pressure and carotid artery blood flow in newborn lambs.

The effects of ECMO on cerebral dynamics, particularly in the face of asphyxia, are largely unknown. We inquired as to whether carotid artery blood flow (CABF) and intracranial pressure (ICP) were affected by carotid artery/jugular vein ligation, asphyxia, ECMO, and ECMO with asphyxia. Lightly sedated newborn lambs (two to four days old, 3 to 4 kg) in four groups were monitored for mean ICP by an epidural sensor, mean CABF by a flow probe, and mean arterial pressure. Mean values were determined for the duration of each step of the experiment. ECMO was venoarterial at 100 to 120 mL/kg/min. CABF and ICP were measured in group 1 before and after CA/JV ligation; in group 2 during normoxia/normocapnia followed by hypoxia (30 to 40 torr)/hypercapnia (70 to 90 torr); in group 3 before, during, after ECMO while normoxic/normocapnic throughout; and in group 4 as ECMO was begun while hypoxic/hypercapnic. Vessel ligation alone caused no significant CABF/ICP changes. Asphyxia caused physiologic increases in CABF (P less than .03) and ICP (P less than .01). ECMO alone caused a significant decrease in ICP (P less than .003). ECMO with asphyxia caused an even more severe decrease in ICP (P less than .001) combined with augmented CABF (P less than .03). The ICP decrease was limited to the duration of ECMO. Possible explanations include loss of cerebral autoregulation induced by hypoxia/hypercarbia and alterations in cerebral venous drainage necessitated by this method of cardiopulmonary bypass.

Animals↗
PubMed1988

Esophageal dilatation and reflux in neonates supported by ECMO after diaphragmatic hernia repair.

Extracorporeal membrane oxygenation (ECMO) for survivors of surgical repair of congenital diaphragmatic hernia was used in 14 neonates. All showed marked esophageal dilatation on postoperative chest radiographs; the dilated esophagus simulated an air- or fluid-filled mass. All patients were later shown to have marked gastroesophageal reflux as well. The finding suggests a problem in swallowing exists before birth, which may explain the recent correlation between diaphragmatic hernia and hydramnios. The observation of a mediastinal mass in neonates with congenital diaphragmatic hernia may represent esophageal ectasia and may be related to significant gastroesophageal reflux.

Dilatation, Pathologic↗
PubMed1987

Reconstruction of penile agenesis by a posterior sagittal approach.

Penile agenesis is a rare condition requiring gender reassignment and staged perineal reconstruction. This report describes two children reconstructed by taking advantage of the posterior sagittal approach. This approach allows a precise anatomic dissection, construction of a neovagina and accurate positioning of all perineal orifices. We think that this is the preferred approach for this rare condition.

Disorders of Sex Development↗
PubMed1987

Residual or recurrent chest mass in pediatric Hodgkin's disease. A surgical problem?

Controversy surrounds the management of a residual chest mass in patients treated for Hodgkin's disease. Between 1971 and 1985, we treated 22 children, aged 7-18 years, with pathologically proven Hodgkin's disease. Nine had radiographic evidence of mediastinal and/or pulmonary involvement. Following treatment, a residual or new chest mass occurred in three patients, prompting surgical exploration. No histologic subtype of Hodgkin's disease predominated in this group. Two patients had received radiotherapy and chemotherapy, and one had received chemotherapy alone. The erythrocyte sedimentation rate (ESR), uniformly elevated at diagnosis, was normal prior to surgery in all three patients. Gallium scans, also uniformly positive at diagnosis, were negative in two patients but positive in a third, suggesting possible relapse. At operation, however, no patient had recurrent Hodgkin's disease. Pathologic findings were thymic fibrosis, mediastinal pseudocyst, and normal thymus, respectively. We conclude that a chest mass following treatment for Hodgkin's disease may be benign, particularly if disease markers such as ESR have normalized. Moreover, a positive gallium scan does not necessarily indicate recurrent Hodgkin's disease. Although surgical exploration is a prudent policy when there is persistent evidence of residual or recurrent chest mass, our experience suggests that immediate exploration is not mandatory and may be deferred for a period of close continued observation.

Adolescent↗
PubMed1987

Extracorporeal membrane oxygenation for neonatal respiratory failure.

Extracorporeal membrane oxygenation will continue to be an appropriate modality of treatment in properly selected infants. In the future, respiratory management and selection criteria for these patients should become standardized and universally accepted. It is conceivable that as we become more comfortable with this treatment we can complete prospective, randomized trials on infants who have less than a 90 percent mortality likelihood and thereby avoid the ethical implications of a study in which the control population has death as an endpoint. It is also conceivable that ECMO will be more benign and induce less morbidity than the barotrauma seen in many of the infants supported by aggressive ventilator management.

Humans↗
PubMed1986

Diaphragmatic activity is a determinant of postnatal lung growth.

To test the hypothesis that activity of respiratory muscles determines regional growth of lung parenchyma, we studied the effects of unilateral diaphragmatic paralysis on contralateral/ipsilateral lung growth in cats and piglets. Five 10- to 12-wk-old cats and five 8-wk-old piglets underwent unilateral diaphragmatic paralysis by thoracic and cervical phrenectomy, respectively. Five to seven weeks after surgery, when the cats were killed for studies of lung growth, gain in body weight was the same as in five sham-operated controls. At this time, mean pleural pressure ipsilateral to the paralyzed hemidiaphragm was the same as contralateral mean pleural pressure during tidal breathing, and values did not differ from controls. However overall functional residual capacity was lower in the phrenectomized cats (35 +/- 4 ml) than in the controls (55 +/- 11 ml, P less than 0.01). Growth of contralateral lungs relative to ipsilateral lungs was greater in the phrenectomized cats than in the controls, as shown by ratios of contralateral/ipsilateral wet lung weight (1.44 vs. 1.34, P less than 0.01), maximum inflation volume (1.53 vs. 1.33, P less than 0.05), and total protein content (1.45 vs. 1.26, P less than 0.05). Ratios of total protein to DNA and RNA to DNA were unchanged. One week after surgery in the piglets, the ratio of contralateral/ipsilateral wet lung weight was increased (1.61 vs. 1.29, P less than 0.01) and total weight of both lungs was reduced. We conclude that regional growth of lung parenchyma by cell proliferation depends in part on regional distribution of respiratory muscle activity.

Animals↗
PubMed1985

Extracorporeal membrane oxygenation and congenital diaphragmatic hernia: modification of the pulmonary vasoactive profile.

We studied the vasoactive profile of a term infant with congenital diaphragmatic hernia and intractable pulmonary hypertension who was refractory to conventional medical management despite an early stable period. Plasma prostanoid vasoconstrictor thromboxane A2 (TxB2) levels were elevated prior to ECMO at 150pg/mL, rose to 310pg/mL with the first hour of bypass and remained elevated until 72 hours by which time they fell to less than 50pg/mL. This coincided with the decreased extracorporeal circulatory support needed to maintain systemic arterial pO2 between 70 to 90 torr. Pulmonary vasodilator prostacyclin (6-keto-PGF1 alpha) was minimally elevated prior to bypass a 50pg/mL and became undetectable. Catecholamine levels were markedly elevated prior to ECMO at 4,000pg/mL with no demonstrable pulmonary extraction of norepinephrine. Though catecholamine levels remained nonspecifically elevated, pulmonary metabolism of norepinephrine improved with bypass time to 48% at 96 hours and coincided with the overall improvement of the infant's respiratory function. These data suggest pulmonary hypertension associated with congenital diaphragmatic hernia is at least partially precipitated by alterations in prostanoid homeostasis as selective activation of thromboxane synthetase pathways rather than nonspecific activation of the entire archidonate cascade. While ECMO per se may have no lasting effect on prostanoid homeostasis, ECMO can allow a period of cardiopulmonary rest during which more physiologic prostanoid levels are established. Although activation of the sympatho-adrenal axis may contribute to pulmonary hypertension, the role of catecholamines in this infant is not clear. Return of the lungs ability to clear norepinephrine may be an additional marker of biologic lung recovery.

6-Ketoprostaglandin F1 alpha↗
PubMed1985

Pediatric hepatobiliary disease.

The surgical aspects of pediatric hepatobiliary disease concern a unique set of diagnoses, disease processes, diagnostic issues, and treatment problems. In this context, this article discusses features of biliary atresia, choledochal cyst, gallbladder disease, and liver abscess in the infant, child, and adolescent.

Adolescent↗
PubMed1982

Aortic thrombosis after umbilical artery catheterization.

Neonatal arterial thrombosis has become more common with the use of umbilical artery catheters; however, catheter-induced aortic thrombosis is rare. A review of the literature disclosed a 100% mortality from medically managed neonatal aortic thrombosis. Two cases of umbilical artery catheterinduced acute neonatal thrombosis were managed successfully by surgical thrombectomy. Severe lower extremity ischemia and hypertension with aortic occlusion developed in two neonates, and intractable congestive heart failure developed in one of the neonates. This seems to be the first documented report of successful surgical treatment of umbilical artery catheter-induced aortic thrombosis. Acute neonatal aortic occlusion should be considered a surgical emergency.

Acute Disease↗
PubMed1982

Ammonia metabolism in dogs with portacaval shunts.

Plasma ammonia, arginine, citrulline and urine ammonia, total nitrogen, and orotic acid were measured in shunted and control dogs. The progressive rise in plasma ammonia in the experimental group could not be explained solely by shunt hemodynamics. Similarity of control and experimental urinary nitrogen does not implicate nitrogen load. Urea synthesis was similar in experimental and control liver slices and was augmented by ornithine only in the experimental slices. Additionally, elevated urine orotic acid suggests urea cycle compromise at the ornithine transcarbamylase step.

Ammonia↗
PubMed1980

Growth of mouse hepatoma following liver resection.

Liver regeneration occurs after resection. Hepatic tumors may be subject to the same factors which influence cell mass in regenerating liver. Partial hepatectomy is shown to cause a significant transient augmentation of tumor growth compared to non-operated and nephrectomized controls. Skin grafting studies indicate this phenomenon is probably not immunologically mediated.

Animals↗
PubMed1979

Vitamin A effect on tumor angiogenesis.

The inhibitory effect of vitamin A on tumor establishment and growth has been studied in two animal models. The C57L/J hepatoma, when placed in C57L/J mice receiving inoculations of vitamin A, showed slow growth and the hosts had significantly prolonged survival over untreated mice. The V-2 carcinoma, when implanted in the corneas of New Zealand white rabbits receiving injections of vitamin A, showed decreased vascular response in the limbic vessels. The absence of an induced vascular response prevents vascularization of the tumor and subsequent tumor growth. The evidence suggests that vitamin A may exert its inhibitory effect by modifying the normal vascular response to neoplastic tissue.

Animals↗
PubMedDate not supplied

Contemporary management of congenital diaphragmatic hernia.

Despite advances in infant transport and intensive care, congenital diaphragmatic hernia (CDH) still poses a serious threat to life during the neonatal period. Only with the introduction of extracorporeal membrane oxygenation (ECMO) has mortality declined significantly. Understanding the pathophysiology of CDH and its devastating effect on the lungs' bronchial and vascular development assists the clinician in rational management during the perioperative period. Successful treatment demands prompt diagnosis, informed preoperative assessment and preparation, carefully timed surgical repair, and aggressive postoperative intensive care with a thorough understanding of the role of ECMO. Improvements in ventilatory support and pharmacologic management of pulmonary hypertension have allowed surgeons to delay repair until circulatory hemodynamics, electrolytes, and oxygenation can be optimized, even resorting to preoperative ECMO in selected cases if needed. Patients with severe bilateral pulmonary hypoplasia pose serious dilemmas in terms of selection for ECMO, as well as for surgical repair. Long-term follow-up of patients after CDH repair reveals persistent hypoperfusion of the involved lung but no debilitating pulmonary disease. Future therapies may include early fetal intervention or lung transplantation, although these areas remain controversial and experimental, and clinical experience is limited.

Female↗