Special article: Pediatric AIDS: Worlds apart

In the United States and in other developed countries, the number of children newly infected with human immunodeficiency virus (HIV) has decreased dramatically as a result of the availability of educational programs, counseling and testing services, and potent anti-HIV therapy. Children with HIV are living longer, healthier lives. However, the pediatric HIV pandemic continues virtually unabated across much of the developing world. The reasons for this difference are complicated and include lack of resources, lack of infrastructure, and lack of trained health professionals in many developing nations. The Baylor International Pediatric AIDS Initiative is addressing these issues by developing comprehensive programs for health professional education and HIV clinical research in parts of the world hardest hit by the HIV acquired immunodeficiency syndrome epidemic. Copyright © 2000 by W.B. Saunders Company     

Q-MOVE:

The study of fetal movement has been characterized in qualitative and quantitative ways. This paper clarifies the use of the term “qualitative” and describes previously developed qualitative assessments of movement. Based on Laban's, Kestenberg's and Al's theories of movement analysis and their terminology, the process of developing a qualitative scale to assess fetal movement is described. The components of the instrument are presented and future use of the research tool are suggested.     

Hyaline Membrane Disease: II: Lung Lecithin

The lecithin content of lung, together with its surface tension properties, were determined in 34 stillbirths, and 61 neonatal deaths. Lecithin content ranged widely from 1·5 to 18·6% of dry lung tissue.In 24 cases the `palmitic-lecithin'' was also measured; it formed 44-79% of the total lecithins. Since the two were related linearly, changes in palmitic-lecithin could be adequately studied by measuring total lecithins.Lecithin content was negatively correlated with minimum surface tension of lung extract in both fresh stillbirths and neonatal deaths. Cases with hyaline membranes had lung lecithin in the lower range (< 8% dry tissue). Lung lecithin content may be a measure of surfactant reserve.After 29 weeks'' gestation, fresh stillbirths and neonatal deaths, other than those with hyaline membranes, had normal lung surfactant. The exception was a small group of infants having immature lungs lacking surfactant, and who survived less than 2½ hours; some of these, it is surmised, would have developed hyaline membranes had they survived longer. This was consistent with the fact that well-formed hyaline membranes were only found in infants that had survived for at least 3 hours.Surfactant deficiency probably develops only after birth (except in very immature infants), and as a consequence of an initial rapid consumption of surfactant to form a lining layer covering the alveolar surface, when a gas-liquid interface is created by aeration of lung. Surfactant deficiency, by promoting interstitial pulmonary oedema, is thought to be the immediate cause of hyaline membrane disease.A scheme for the pathogenesis of hyaline membrane disease is set out. It provides a possible mechanism for the different ways in which surfactant deficiency may arise in immature and mature infants.Cases where hyaline membranes occur with normal surfactant fall into three groups: (1) Cases with hyaline membrane disease that have survived several days, the lungs being in the stage of repair. (2) Cases with massive lung haemorrhage, with severe anaemia from haemolytic disease, or with heart failure; extravasation of oedema fluid or blood may be the common factor in this group. (3) Infants of diabetic mothers.     

Hyaline Membrane Disease: I: Cellular Changes

Cellular changes were studied in 1 μ thick sections of lungs from 84 perinatal deaths, including 44 with hyaline membrane disease (HMD). The presence or absence of osmiophilic granules was related to surface tension measurements in 69 cases. The presence of numerous granules usually indicated normal surfactant and their absence a lack. It is concluded that the granules represent surfactant material.Osmiophilic granules were found first at 20 weeks'' gestation (in 2 out of 6 fetuses). After 24 weeks'' gestation almost all infants had many granules, except those with HMD.The earliest stages in hyaline membrane formation consisted of interstitial oedema accompanied by localized areas of necrosis and desquamation of alveolar epithelial cells. Osmiophilic granules were virtually absent.Infants dying at a later stage of the disease showed more extensive hyaline membranes, but from 36 hours almost all cases displayed some signs of repair of the denuded alveolar surfaces. In 5 out of 10 cases with evidence of repair, normal values for surface tension were obtained.In the late stages of HMD some of the cells lining the alveoli were highly abnormal. They consisted of large thick squames with very few capillaries in apposition to them; the appearances were thus consistent with a severe degree of alveolo-capillary block.