Antioxidant effect of retinoic acid on PC12 rat pheochromocytoma.

Retinoic acid is a naturally occurring metabolite of vitamin A that influences the differentiation of a variety of neural cells in vitro. In the LA-N-1 human neuroblastoma line, retinoic acid treatment increases the binding of nerve growth factor (Bmax). The purpose of this study was to examine the effects of retinoic acid on PC12 rat pheochromocytoma, a neural crest-derived cell line that can be induced to express a sympathetic neuroblast-like phenotype by nerve growth factor treatment. In contrast to the differentiating effects of nerve growth factor, retinoic acid treatment of PC12 cells had a negligible effect on cellular morphology. However, treatment with retinoic acid enhanced the survival of PC12 cells following oxidative injury generated by H2O2 treatment in a manner that is qualitatively similar to that observed after nerve growth factor treatment. Also, there was an increase in 125I-nerve growth factor binding activity in solubilized PC12 membrane preparations derived from retinoic acid-treated PC12 cells. These data suggest that retinoic acid may play a role in neuronal development and in neuronal injury by stimulating the ability of neurons to cope with oxidative stress and/or by enhancing neuronal responsiveness to trophic factors such as the nerve growth factor.

Normal hematologic values and prevalence of anemia in children living on selected Pacific atolls.

The hematologic status of infants and children living on the small islands of the Pacific basin has been poorly documented. This report determines the normal ranges for hemoglobin (Hb) and mean corpuscular volume (MCV) for children residing on four of the small atolls of the Republic of the Marshall Islands in the archipelago of Micronesia. The difficulty in establishing normal hematologic values in pediatric populations is discussed and a methodology suggested that does not exclude any Hb value above the mean in determining the normal range for Hb. The study population was comprised of 563 Marshallese children representing approximately 3.4% of all children less than 16 years of age living in the Marshall Islands. The local prevalence of anemia and iron deficiency was also established.

Infective endocarditis following cardiac catheterization in infancy. A case report and review.

A 4.5-month-old infant with transposition of great vessels and large ventricular septal defect developed acute infective endocarditis following cardiac catheterization. Beta-hemolytic streptococcus was recovered from three blood cultures. The infant survived after 6 weeks intravenous antibiotic therapy. The occurrence of infective endocarditis following cardiac catheterization during infancy is briefly reviewed and discussed. The importance of distinguishing febrile episodes of infancy from infective endocarditis and the use of two-dimensional echocardiography for diagnosis is re-emphasized.

Pediatrics in the Marshall Islands.

The delivery of health care to children living on isolated island communities presents unique challenges to health professionals. An evolved method of providing longitudinal services to infants and children residing on islands of the Marshall Island chain--a central Pacific portion of the Micronesian archipelago--is presented. The difficulties associated with provision of comprehensive health care in a vast ocean area are discussed.

Projecting physician requirements for child health care-1990.

In 1976 the Secretary of the Department of Health, Education and Welfare appointed the Graduate Medical Education National Advisory Committee (GMENAC) with the charge to advise the Secretary on five national health planning objectives, including estimates of the numbers of physicians required to meet the health care needs of the nation, recommendations regarding the most appropriate specialty distribution of these physicians, and development of strategies to achieve the recommendations formulated by the committee. GMENAC evaluated projected supply and requirements for all major specialties, including child health care, for 1990, and recommended strategies to bring supply and requirement into reasonable balance. Despite the range of error of the methodology used, these data represent the most detailed scientific study to date on this subject. Pediatrics, the portion of child health care accruing to the pediatrician in 1990 was projected to be in "near balance" for supply/requirement ratio. Inasmuch as GMENAC recommended that larger surpluses be created deliberately in the three primary care fields, it is unlikely that the numbers of pediatric residency training programs will be decreased. As several hundred pediatric residency positions are unfilled each year, a concomitant decrease in residency offerings in oversupplied fields would be required to accomplish the recommended subspecialty distribution.

Systemic hypertension in children.

Hypertension is a common disease which may often be modified, sometimes cured and, perhaps in some cases, prevented. This communication emphasizes the importance of obtaining blood pressure measurements in children no later than at the age of 3 years and sequentially thereafter, and stresses the importance of using techniques for measuring blood pressure which assure accuracy. Levels of blood pressure readings diagnostic of hypertension are suggested. The evaluation of hypertensive children is outlined. The classification and differential diagnosis of hypertension is reviewed. Current concepts in nonpharmacologic and pharmacologic therapy for hypertension in children and youths are presented. Therapy for acute hypertensive crisis is described.

Surgical correction in infancy to reduce mortality in transposition of the great arteries.

The mortality for infants with transposition of the great arteries (TGA) prior to the introduction of medical and surgical septostomy was over 80% by 6 months of age. The mortality has fallen recently, due to balloon atrial septostomy (BAS), but still exceeds 25% by 6 months of age in major centers. The cumulative mortality rises to 40% by 1 year of age with or without additional surgical atrial septectomy. In our center, 12 patients with an average age of 3 months were operated on for interatrial baffle correction of their TGA under surface-induced deep hypothermia. BAS had been done preliminarily in those patients without an adequate atrial communication. Ten of these 12 patients (83%) survived. These patients have been followed up from one month to eight years with an average follow-up of over four years. Surgical correction during infancy offers a better survival rate for infants with TGA than does medical management, with or without palliative surgery.

Rheumatic mitral regurgitation. The case for annuloplasty in the pediatric age group.

Eight youngsters (five female, three male, ages 10 to 19 years, mean 15 years) with isolated severe rheumatic mitral regurgitation have been subjected to mitral annuloplasty because of limiting symptoms and prominent ECG and X-ray changes. They have been followed for up to 11 years (mean 3.7 years), and 7 have had excellent results. An early (1961) patient had a small annulus and was not a favorable candidate; he had only transient improvement. Seven are greatly improved, have decreased cardiac size (often dramatic), and have improved ECG's. One has undergone successful pregnancy, and none has been limited in activities. The extent and duration of improvement, lack of mortality, and resumption of normal activities by these youngsters indicate surgical success. The essence of childhood and youth is activity and the future life span hopefully long; hence, annuloplasty would appear to be the procedure of choice for severe rheumatic mitral regurgitation in the pediatric age group, avoiding the usual need for anticoagulation and uncertain long-term results associated with mitral valve replacement.