Splenic macrophages in preterm infants: a necropsy study

AIMS: To study the frequency and nature of histiocytes in the splenic red pulp of infants who died following complicated immaturity/prematurity. METHODS: Twenty four preterm/immature infants were investigated. Frozen sections of formalin fixed splenic tissue were stained with Oil Red O. Paraffin wax sections from the same tissue were conventionally stained with haematoxylin and eosin. Immunohistochemistry was carried out for a number of macrophage markers. The administration of Intralipid was compared with the presence and extent of tissue macrophages. RESULTS: The spleens of 10 infants showed varying degrees of Oil Red O positivity ranging from mild to strong. In all these cases varying numbers of macrophages were confirmed in the splenic parenchyma in ordinary sections. The immunomarkers indicated that the histiocytes belonged to the macrophage phagocytic system. Of the 10 cases with splenic macrophages all had received Intralipid. Of those not receiving Intralipid none showed splenic macrophages. Seven had received Intralipid but did not have splenic macrophages; they had either only received small amounts of Intralipid or Intralipid was discontinued before death. CONCLUSIONS: Splenic macrophages are common at necropsy in immature/preterm infants. The macrophages are most lucidly demonstrated using Oil Red O staining in frozen sections. There is a strong association between the presence of splenic macrophages and Intralipid administration.     

The effects of concept training on interproblem transfer in rats.

Assigned 24 hooded rats, matched for intelligence on the Hebb-Williams maze, to 3 groups. Groups I and II were trained on 10 2-choice simultaneous discrimination problems (56 trials/problem); for Group I, positive discriminanda had the feature of curvature in common. Group III were untrained controls. On transfer to 10 unrelated discrimination problems (20 trials/problem), Group III ran at 50% correct. Group I was significantly superior to all other groups and Group II was significantly superior to Group III. It is concluded that training on related problems leads to a more efficient reduction of error tendencies than training on unrelated problems. (French summary) (21 ref.) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Deformation of the palate in preterm infants

AIM: To investigate the effect of gestation, postmenstrual age, and orotracheal intubation on palate morphology. METHODS: A prospective study was made of 76 newborn infants of 25 to 41 weeks' gestation. Palate dimensions were measured on plaster models produced from serial palatal impressions. Palate size relative to that of the mouth was assessed using a ratio of palate depth to palate width (Palatal Index). RESULTS: Palate depth and width were related to postmenstrual age and gestation. Palatal Index ranged from 0.15 to 0.57, indicating a wide variation in palate shape, but gestation and postmenstrual age had no effect. Prolonged intubation had a small effect, equivalent to an increase in palatal depth of less than 2 mm at 32 weeks' postmenstrual age. The effect was transient. CONCLUSION: Prolonged orotracheal intubation (> 10 days) leads to a small and temporary increase in palatal depth. However, this is unlikely to account for palatal grooving, which is probably caused by an overgrowth of the lateral palatine ridges.     

Epilepsy in very preterm infants: neonatal cranial ultrasound reveals a high-risk subcategory

Osteoporotic fractures, and in particular, hip fractures result in significant morbidity and mortality. Low bone mass is the main risk factor of enhanced bone fragility, resulting in an increased risk for hip fracture. Bone density of osteoporotic women with and without hip fractures show a considerable overlap. Therefore, other bone-independent factors also play an important role for the development of hip- and other osteoporotic fractures. One other important factor is falling. In 90% of hip fractures falling was involved [10-15], but only 5% or less of these falls resulted in a subsequent fracture. The view that adequate exercise is beneficial for skeletal health of children and for prevention and treatment of osteoporosis in adults is supported primarily by two lines of evidence: longitudinal and cross-sectional trials in children and young adult athletes showing a significant increase of muscle- and bone mass after strenuous (children) or chronic exercise (athletes) as compared to normally active (children) or sedentary control subjects. What are the potential benefits and limits of specific exercise programs with respect to bone mass, prevention of falls and fractures? In this review these questions are discussed and a specific exercise program in osteoporotic patients with fractures is delineated.     

Developmental changes in response to heelstick in preterm infants: a prospective cohort study

Twenty-eight preterm infants of 28 weeks gestational age were observed four times over eight weeks in order to determine changes in their pain response. Both routine and sham heelstick procedures were used. Physiological (heart rate and oxygen saturations) and behavioural parameters (three upper facial actions) were used as outcomes. The responses to real heelstick were significantly greater than to sham heelstick for heart rate and all facial actions except one at 28 weeks gestational age, but not for oxygen saturation. The magnitude of response to both real and sham heelstick increased over time. Thus, the older the infant, the more robust and recognisable the response. Since even the youngest infants showed a differential response to pain, professionals caring for such infants need to be able to recognize their more subtle pain responses.     

Breath pentane as a marker for lipid peroxidation and adverse outcome in preterm infants

AIM: To test the hypothesis that complications of neonatal intensive care are related to increased oxygen derived free radical activity, using breath pentane as a marker of lipid peroxidation. METHODS: Exhaled breath was collected daily from 57 ventilated preterm infants and pentane concentration measured by gas chromatography. RESULTS: High peak pentane exhalation was significantly associated with low gestational age, mortality, intraventricular haemorrhage and retinopathy of prematurity. Peak pentane was not significantly associated with the development of chronic lung disease. CONCLUSIONS: The demonstration that pentane exhalation is related to the course of neonatal disease and its outcome is consistent with the hypothesis that lipid peroxidation is associated with these illnesses, and may contribute to their severity. If this is a causal relation, antioxidant treatments could prove useful in reducing their severity. Measurement of breath pentane might assist in the assessment of antioxidant strategies prior to more extensive clinical trials.     

Randomised controlled trial of L-carnitine as a nutritional supplement in preterm infants

AIMS: To evaluate the effect of L-carnitine supplementation (25 mg/kg/d) on the growth and incidence of hypoglycaemia in preterm infants. METHODS: A double blind, placebo controlled randomised trial, stratified for gestational age, was conducted of 86 preterm infants between 28 and 34 gestational weeks. The median gestational ages in the carnitine group and placebo groups were 30.7 weeks (range 28.0 to 33.6) and 31.4 weeks (range 28.0 to 33.9), respectively. The median birthweights were 1.557 kg (range 0.944 to 2.275) and 1.645 kg (range 0.885 to 2.545), respectively. RESULTS: Mean plasma free carnitine concentrations were below values for normal term infants in both groups on day 1 (carnitine group 44.8 mumol/l, placebo group 25.5 mumol/l) in the placebo group on day 7 (50.7 mumol/l), but in neither group on days 14 and 28. Total, free, and acylcarnitine concentrations were significantly increased in both urine and blood in the L-carnitine group. There was no significant difference between the placebo and carnitine supplemented groups in growth rate, as assessed by weight, length, skinfold thickness and head circumference measurements, or in the incidence of episodes of hypoglycaemia. CONCLUSION: The addition of carnitine as a nutritional supplement at a dose of 25 mg/kg/day did not improve growth in our group of preterm infants nor protect them from episodes of hypoglycaemia.     

Neonatal neutrophil activation is a function of labor length in preterm infants

To understand better the development of the neonatal immune system, we evaluated the role of labor length, gestational age, and mode of delivery on the expression of the neonatal neutrophil cell surface antigens CD11b, CD11c, CD15, CD33, and CD66b in premature newborns. Peripheral blood samples from 68 apparently healthy preterm infants were obtained within 12 h of birth and incubated with MAb to the CD antigens. Samples were lysed, fixed, and analyzed by flow cytometry. Multivariate analysis was used to study the simultaneous effect of the labor length and gestational age on the neonatal neutrophil cell surface antigen expression. A positive correlation was demonstrated between neutrophil antigen expression and labor length (p < 0.001-0.026) but not with the mode of delivery (p = 0.191-0.638). There was no significant correlation between expression of neutrophil antigens and gestational age at delivery (p = 0.057-0.866), except for CD15 (p = 0.010). Our results indicate labor length is a significant factor in neonatal neutrophil activation at birth. These findings are independent of gestational age in preterm newborns. Mode of delivery does not seem to influence neonatal neutrophil activation. The neutrophils of premature infants can be activated antenatally and/or during labor.     

Inhibitory effect of dopamine treatment on Na+/K(+)-ATPase activity in preterm infants

A range of neural pathology, in particular meningitis with sporadic encephalitic extension, can develop in salmonids infected with Renibacterium salmoninarum, the agent of bacterial kidney disease (BKD). Tissues from 134 Atlantic salmon and 164 chinook salmon were selected on the basis of their having a positive diagnosis of BKD, with evidence of multi-tissue infection including the brain (214 fish), or brain involvement in the absence of systemic lesions attributable to BKD (58 fish). Although meningitis was a feature of BKD in both species, encephalitis was more common in the Atlantic salmon. Specifically, a higher portion of the Atlantic salmon had encephalitis accompanying meningitis (P = 0.0159), encephalitis in the absence of meningitis (P = 0.0756), and brain lesions (meningitis or encephalitis) in the apparent absence of systemic lesions (P = 0.0067). These findings suggest either that some aspects of the pathobiology of R salmoninarum are dictated by the host species, or that the farm management methods used to deal with BKD are sufficiently different for the two species of salmon that they affect the pathology of the disease.     

Skin-to-skin contact beginning in the delivery room for Colombian mothers and their preterm infants

To determine if the transition to extrauterine life is facilitated by skin-to-skin contact, six relatively low risk preterm infants experienced six continuous hours of skin-to-skin contact on their mothers' chests beginning within 30 minutes of birth. Heart and respiratory rates and oxygen saturation remained within normal limits and all infant temperatures rose rapidly to thermoneutral range. Two infants developed grunting respirations by the time skin-to-skin contact began, but the grunting disappeared with warm, humidified oxygen and continuous skin-to-skin contact. All infants were fully breastfeeding and ready for discharge by 24-48 hours postbirth. Early skin-to-skin contact was safe and seemed beneficial for these relatively low risk preterm infants.     

Mediastinal cyst involving the oesophagus: diagnosis and results of surgical treatment

OBJECTIVE: To describe our experience with mediastinal cysts involving the oesophagus. DESIGN: Retrospective study. SETTING: University hospital, Italy. SUBJECTS: 11 patients who presented to our department with a mediastinal cyst from 1976-1994. INTERVENTIONS: Excision of the mass through a posterolateral thoracotomy (n = 10) or by video-assisted thoracoscopy. MAIN OUTCOME MEASURES: Morbidity and mortality. RESULTS: 8 patients presented with retrosternal or epigastric pain, three of whom had mild dysphagia. In the remaining 3 the tumour was asymptomatic and an incidental finding on a chest radiograph. Endoscopic ultrasonography and computed tomography (CT) allowed preoperative diagnosis of an extramucosal cyst in 5 of the 7 patients investigated by both tests. Masses were excised through a formal thoracotomy (n = 10) or by video-assisted thoracoscopy. Histological examination confirmed a benign cyst in all cases. There was no operative morbidity and nine patients are free of symptoms after a median follow-up of 2.3 years. CONCLUSION: Excision, preferably by thoracoscopy, is the treatment of choice for mediastinal cysts that involve the oesophagus. Special attention should be paid to the vagal nerves, and as many as possible of the muscular layers of the oesophagus should be preserved.     

Ampicillin-metronidazole treatment in idiopathic preterm labour: a randomised controlled multicentre trial

OBJECTIVE: To determine whether treatment with ampicillin and metronidazole in women with threatened idiopathic preterm labour will prolong the gestation and reduce maternal and neonatal infectious morbidity. DESIGN: Randomised controlled double-blind trial. SETTING: Six obstetric departments in the Copenhagen area. POPULATION: One hundred and twelve women with singleton pregnancies, with threatened idiopathic preterm labour and intact amniotic membranes at 26 to 34 weeks of gestation. METHODS: Random allocation to eight days intravenous and oral treatment with ampicillin and metronidazole, or placebo. MAIN OUTCOME MEASURES: Number of days from admission to delivery, gestational age at delivery, rates of preterm delivery, low birthweight, maternal infections and neonatal infections. RESULTS: Treatment with ampicillin and metronidazole was associated with a significant prolongation of pregnancy (admission to delivery 47.5 days versus 27 days, P < 0.05), higher gestational age at delivery (37 weeks versus 34 weeks, P < 0.05), decreased incidence of preterm birth (42% versus 65%, P < 0.05), and lower rate of admission to neonatal intensive care unit (40% versus 63%, P < 0.05), when compared with placebo treatment. Antibiotic treatment had no significant effects on infectious morbidity. CONCLUSIONS: Treatment with ampicillin and metronidazole in women with threatened idiopathic preterm labour significantly prolonged the gestation, but had no effects on maternal and neonatal infectious morbidity.     

Structural dynamism in the concept of self: A flexible model for a malleable concept.

The self-concept is theorized to play an important role in many psychological processes. Numerous theories rest on assumptions concerning the differential accessibility of pieces of self-knowledge, but relatively little attention during the past decade has centered on examining the underlying structure of the self-concept that mediates such differences. In the present article, we suggest a new model of the self-concept that incorporates recent advances in knowledge regarding conceptual structure. We envision the self as a representation in working memory with inherently flexible content and organization. Initial empirical evidence supporting this view is reviewed and followed by a discussion of the implications of this model for many phenomena involving the self-concept. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Pulmonary artery pressure: early predictor of chronic lung disease in preterm infants

AIM: To determine if pulmonary artery pressure (PAP) in ventilated preterm infants is independently associated with the development of chronic lung disease (CLD) and whether early assessment has any prognostic value. METHODS: Two cohorts (development n = 55; and validation n = 28) of preterm infants were studied at 24 hours of age. PAP was assessed non-invasively using its inverse correlation with the corrected acceleration time to right ventricular ejection time ratio (AT:RVET(c)), calculated from the pulmonary artery Doppler waveform. Clinical and respiratory variables were also collected. Using logistic regression analysis to identify factors independently associated with CLD, a prognostic score was developed to predict CLD. The ability of the score to predict CLD was described using receiver operating characteristic (ROC) curves. RESULTS: Birthweight, inspired oxygen concentration, and AT:RVET(c) were independently predictive of CLD. The area under the ROC curve was 0.96 for the development and 0.89 for the validation cohort. Exclusion of AT:RVET(c) resulted in a reduction to 0.88 and 0.73, respectively. CONCLUSION: PAP is independently associated with CLD. An early assessment of PAP using AT:RVET(c) may permit the early prediction of CLD as part of a multifactorial scoring system.     

Direct measurement of the energy expenditure of physical activity in preterm infants

The energy cost of physical activity (EEA) has been estimated to account for 5-17% of total energy expenditure (TEE) in neonates. To directly measure EEA, a force plate was developed and validated to measure work outputs ranging from 0.3 to 40 kcal . kg-1 . day-1. By use of this force plate plus indirect calorimetry, TEE and EEA were measured and correlated with five activity states in 24 infants with gestational age of 31.6 +/- 0.5 (SE) wk and postnatal age of 24.8 +/- 3.7 days. TEE and EEA were 69.2 +/- 1.5 and 2.4 +/- 0.2 kcal . kg-1 . day-1, respectively. EEA per state was 0.5 +/- 0.0 (quiet sleep), 2.4 +/- 0.2 (active sleep), 2.8 +/- 0.4 (quiet awake), 7.5 +/- 0.8 (active awake), and 15.1 +/- 2.3 (crying) kcal . kg-1 . day-1. This provides the first direct measurement of the contribution of physical activity to TEE in preterm infants and will enable measurement of caloric expenditure from muscle activity in various disease conditions and development of nursing strategies to minimize unnecessary energy losses.