A revised rule of thumb for predicting haematocrit rise in premature infants following packed red blood cell transfusion

The purpose of this study is to compare a revised rule of thumb with the Harriet Lane and Behrman's formulas for predicting haematocrit rise following packed red blood cell (PRBC) transfusion in premature neonates. Pre- and post-transfusion, equilibrated central haematocrits were obtained within 24 h of transfusion in 12 premature neonates undergoing 18 transfusions. Iatrogenic blood loss between pre- and post-transfusion haematocrit determinations was measured for each transfusion event, and infants with detectable, non-iatrogenic blood loss were excluded. Expected haematocrit rise was calculated three different ways using the Behrman, Harriet Lane, and proposed formulas (see text). The Harriet Lane formula predicted haematocrit rise with a correlation, r = 0.66 and slope m = 0.43. The Behrman's formula predicted haematocrit rise with a correlation r = 0.81 and slope m = 0.60. The proposed formula predicted haematocrit rise with a correlation r = 0.79 and slope m = 0.56. On the basis of these findings, we propose the following formula: Quantity PRBC transfused (ml) = 4/3 X desired haematocrit rise X weight (Kg) This formula takes into account the higher blood volume per kilogram body weight seen in premature infants while estimating PRBC unit haematocrit as 0.75 to obviate the need of measurement before each transfusion and, therefore, is an accurate, practical, and simple replacement for the Harriet Lane and Behrman's formulas.     

Degeneration of oxidative muscle fibers in HTLV-1 tax transgenic mice.

The HTLV-1 tax gene under control of the HTLV-1 long terminal repeat (LTR) was introduced into transgenic mice. Previously tax protein expression in the muscle and peripheral nerves of three independent mouse lines was reported. Here the localization of this transgenic protein at a cellular and subcellular level is described. Tax protein was expressed in oxidative muscle fibers that developed severe progressive atrophy. It localized to the cytoplasma where it was associated with structures resembling degenerating Z bands. This pattern of muscle fiber involvement is similar to that observed in human retroviral associated myopathy. This transgenic mouse model suggests that preferential expression of the HTLV-1 viral promoter in oxidative muscle fibers may explain the productive infection of these fibers in HTLV-1 myopathy.     

Cortical dendritic pathology in human immunodeficiency virus encephalitis.

Previous neuropathological and morphometric studies of the cerebral cortex of patients with human immunodeficiency virus encephalitis (HIVE) have shown a decrease in the population of large neurons, moderate loss in synaptophysin immunoreactivity, and pathological changes in dendrites. To further characterize and quantify alterations in the dendritic tree of neocortical pyramidal neurons, we performed a modified Golgi impregnation technique on Formalin fixed blocks from the frontal cortex of 5 HIVE cases, 5 human immunodeficiency virus seropositive control cases without encephalitis, and 5 human immunodeficiency virus seronegative controls. Apical dendrites of HIVE cases were dilated, vacuolated, and tortuous with decreased length and branching. Basal and oblique dendrites also showed these alterations, but to a lesser extent. Some dendrites presented lacunae and filopodia consistent with remodeling. Computer aided quantification of HIVE cases showed a 40-60% decrease in spine density throughout the entire length of dendrites. Laser confocal imaging of Golgi impregnated sections displayed aberrant spines in regions of abnormal second order dendritic branches. These observations support the role of primary dendritic damage in HIVE in contrast to other neurodegenerative disorders where the primary pathology is presynaptic.     

Rubinstein-Taybi syndrome medical guidelines

Children and adults with Rubinstein-Taybi Syndrome have specific medical conditions that occur with greater frequency than the general population. Based on the available information from the literature and clinical experience, recommendations for specific surveillance and interventions are made to guide those clinicians caring for individuals with Rubinstein-Taybi Syndrome. This is a first attempt at medical guidelines for individuals with RTS in the United States. On-going research is needed in many areas to guide decisions in medical care and allow for refinement of these medical guidelines.     

The utility of ancillary studies in pediatric FNA cytology.

We evaluated the diagnostic contribution of adjunct studies performed on aspirated material in the work-up of pediatric fine-needle aspiration (FNA) biopsies. Ancillary studies were performed on 54 of 136 (39.7%) pediatric FNA biopsies during a 5-year period. In 23 (16.9%) cases, immunocytochemical (ICC) studies, consisting of immunoperoxidase staining of direct smears and/or cell blocks or flow cytometric immunophenotyping, were performed. The studies were adequate in 14 cases (60.9%), suboptimal in five cases (21.7%), and inadequate in four cases (17.4%). Of the adequate and suboptimal cases, the ICC data helped to narrow the differential diagnosis or classify the disease process in eight cases (42.1%), confirmed cytologic impression in nine cases (47.4%), and gave contradictory results in two cases (10.5%). Adequate material for electron microscopy (EM) was obtained in 14/19 cases (73.7%). Ultrastructural studies were diagnostic, or helped classify the disease process in five cases (35.7%), confirmed the cytologic impression in four cases (28.6%), helped exclude diagnostic considerations in three cases (21.4%), and were judged to be non-contributory in two cases (14.3%). Cytogenetic studies revealed six of seven cases (all neoplasms) to have abnormal karyotypes. Special stains for organisms performed on smears from 25 cases including Ziehl-Neelsen, Gomori methenamine silver (GMS), Gram, and Warthin-Starry (WS) were negative except for 1/16 GMS and 4/9 Gram stains. In summary, we found that with appropriate case selection, ancillary studies performed on aspirated material can provide useful information in pediatric FNA cytology.     

Exercise improves biomarkers of health and stress in animals fed ad libitum

Voluntary and forced exercise decrease morbidity and mortality in laboratory animals. Caloric restriction has similar effects on health and unique benefits on life span. Nonetheless, in most experiments, animals do not have access to physical activity and are fed ad libitum (AL). We hypothesized that with regular access to either unlimited running wheel exercise (EX) or limited physical activity (PA), key biomarkers of health would be enhanced enough to counter some consequences of a sedentary AL lifestyle. This 16-month study compared body weight, tumor number and size, tissue lesions, oxidative stress, and reactive stress in (1) sedentary animals with no access to physical activity (SED); (2) animals with access to hour-long, twice weekly activity in a large box (PA); and (3) animals with access every other day to a running wheel (EX). At the end of the study, EX body weight was 8-9% lower than PA and SED. In addition, EX had no kidney lesions versus 50% in PA and SED, and had smaller tumor size (10+/-2 vs. 14+/-4 and 30+/-4 mm). Exhaustive exercise lowered glutathione/oxidized glutathione ratio in EX and PA, but in SED, the ratio was depressed even in resting animals. In all treatments, prolactin (PRL) levels were lower in resting animals than in acutely exercised animals. In conclusion, EX had the most favorable health biomarkers while SED had the least. PA did not confer gross health benefits different than the SED group, but was biochemically more similar to EX animals.     

Effect of preparation techniques on mixing of additives in intravenous fluids in nonrigid containers

It has been observed that the procedures of some hospitals do not require any mixing after drugs are added to intravenous bags. Previous studies have shown that mixing often is incomplete in the absence of specific mixing procedures. It has been asserted that mixing is effected by normal handling of bags, and that mixing is sufficient if drug is added to "bottom up" bags, which are then inverted. In this study the extent to which mixing occurred on addition of KCl solution or water to intravenous bags as a function of bag and needle position, additive, speed of addition, and bag handling procedure was determined. Also determined was the extent to which mixing occurred spontaneously. Most important, we determined the effect of incomplete mixing on the concentration of drug actually delivered from the bags. It was concluded that mixing is critically dependent on many factors, and that an effective technique to achieve complete mixing is essential to assure homogenous solutions. The most effective method of mixing solutions in plastic infusion bags is to grasp the bag by its two ends and rapidly invert it twice. This "double inversion" mixing technique, a maneuver requiring only 2 seconds, assures complete mixing of intravenous solutions.     

Congenital pulmonary atresia with ventricular septal defect: angiographic and surgical correlates

Of 181 patients with severe congenital pulmonary atresia and ventricular septal defect or "type IV truncus" (an obsolete term), all but 11% had true central pulmonary arteries. These arteries were demonstrable by large serial biplane angiograms using multiple selective injections into collateral vessels, frequent photographic subtraction, and occasional pulmonary vein-wedge angiograms. These techniques are extremely important for accurate diagnosis and in planning corrective or palliative surgery, which was done in 77% of patients with pulmonary arteries.