Exudative lung injury is associated with decreased levels of surfactant proteins in a rat model of meconium aspiration

OBJECTIVE: Meconium aspiration syndrome remains a common cause of respiratory failure in neonates. The acute effects of meconium aspiration are inactivation of lung surfactant in vivo and in vitro. This study investigated the delayed effects of meconium on alveolar surfactant phospholipids and protein levels in spontaneously breathing animals. METHODS: Twenty-two adult rats were given 4.3 mg of dry weight human meconium after endotracheal intubation. Rats were briefly mechanically ventilated in room air, extubated, then killed after 16 (n = 6), 24 (n = 6), 48 (n = 6), and 72 hours (n = 4). Control animals received the same volume of normal saline (n = 7) or no meconium (n = 7). Bronchoalveolar lavage and tissue specimens were evaluated for inflammatory cells, total proteins, surfactant phospholipids, and surfactant proteins. RESULTS: Meconium caused exudative lung injury that was reflected in increased cell counts and proteins in alveolar lavage fluid. The peak injury occurred at 16 hours after instillation, whereas recovery occurred by 72 hours. Although total lavage fluid phospholipids did not change over time, phospholipid and dipalmitoyl phosphatidylcholine in large aggregates tended to decrease at 24 hours. Western blot analysis demonstrated time-dependent qualitative decreases in surfactant proteins A and B (SP-A, SP-B) in meconium-instilled animals compared with the controls. ELISA for SP-B confirmed the Western blot findings with total SP-B in large aggregate decreasing from 25 +/- 4 microg in controls to 6.6 +/- 0.8 microg at 24 hours of injury. CONCLUSIONS: Our study suggests that the exudative lung injury with meconium instillation is associated with decreased levels of SP-A and SP-B in the large aggregate fraction of lung surfactant. We speculate that decreased secretion and/or increased degradation accounts for lower levels of SP-B in bronchoalveolar lavage fluid.     

Perforated diverticulum of the ascending colon: Pre-operative diagnosis by ultrasound

A case of acute perforation of a diverticulum of the ascending colon is presented. The ultrasound features that helped in making a pre-operative diagnosis are discussed. This rare surgical emergency and the similar clinical entities of perforated caecal or transverse colon diverticula are often clinically misdiagnosed as more common conditions such as acute appendicitis, acute cholecystitis or perforated ulcer. Awareness of this entity will help radiologists in making a correct pre-operative diagnosis.     

Association between uncoupling protein polymorphisms (UCP2-UCP3) and energy metabolism/obesity in Pima indians

The UCP2-UCP3 gene cluster maps to chromosome 11q13 in humans, and polymorphisms in these genes may contribute to obesity through effects on energy metabolism. DNA sequencing of UCP2 and UCP3 revealed three polymorphisms informative for association studies: an Ala-->Val substitution in exon 4 of UCP2, a 45 bp insertion/deletion in the 3'- untranslated region of exon 8 of UCP2 and a C-->T silent polymorphism in exon 3 of UCP3. Initially, 82 young (mean age = 30 +/- 7 years), unrelated, full-blooded, non-diabetic Pima Indians were typed for these polymorphisms by direct sequencing. The three sites were in linkage disequilibrium ( P < 0.00001). The UCP2 variants were associated with metabolic rate during sleep (exon 4, P = 0.007; exon 8, P = 0.016) and over 24 h (exon 8, P = 0.038). Heterozygotes for UCP2 variants had higher metabolic rates than homozygotes. The UCP3 variant was not significantly associated with metabolic rate or obesity. In a further 790 full-blooded Pima Indians, there was no significant association between the insertion/deletion polymorphism and body mass index (BMI). However, when only individuals >45 years of age were considered, heterozygotes (subjects with the highest sleeping metabolic rate) had the lowest BMI (P = 0.04). The location of the insertion/deletion polymorphism suggested a role in mRNA stability; however, it appeared to have no effect on skeletal muscle UCP2 mRNA levels in a subset of 23 randomly chosen Pima Indians. In conclusion, these results suggest a contribution from UCP2 (or UCP3) to variation in metabolic rate in young Pima Indians which may contribute to overall body fat content later in life.      

Distress and the micturating cystourethrogram: does preparation help?

This study evaluates the impact of therapeutic preparation methods on children undergoing MCUG. Parents of 35 children who had undergone MCUG were surveyed by questionnaire. The child's reaction to investigation was assessed using the Groningen Distress Rating Scale (rating 1 = calm > 5 = panic) and parental coping styles using the Utrecht Coping List. Families received one of two types of therapeutic preparation: storybooklet or storybooklet and play preparation. Reported distress levels were significantly lower with therapeutic preparation (mean score 2.5 ± 1.02 SD) than without (mean score 3.3 ± 1.22 SD). Previously, controls reported 46% of anxiety-linked behaviour changes post-MCUG, falling to 13% after therapeutic preparation. Parents who gave a candid explanation reported significantly lower child distress levels (mean 2.0 ± 0.91 SD) than those parents who avoided upsetting details (mean 3.1 ± 0.47 SD). We conclude that distress associated with the MCUG can be reduced by therapeutic preparation of the child and family prior to investigation.     

MAG3 renal scintigraphy: Improved ability to make anatomical diagnoses in neonates

Technetium-99m mercaptoacetyltriglycine(MAG3) is the most recently introduced renal radiopharmaceutical in Australia and is established as the agent of choice for use in diuresis renography, particularly in neonates and infants. It provides superior anatomical information compared to previously used agents. Three cases are reported in which MAG3 diuresis renography was performed in neonates, who were found to have hydronephrosis detected antenatally. In two neonates, a previously unrecognized horseshoe kidney was demonstrated and in case 3 there were scan features characteristic of a ureterocele. It is highly unlikely that these abnormalities would have been delineated with ^99mTc dimethyltriamine penta-acetic acid (DTPA) study, as confirmed in case 1, because of the relatively poor uptake of DTPA when compared to MAG3.     

EFFECT OF DILUENTS ON MOTILITY OF RAM SPERM DURING STORAGE AT 5°C

This study examined the effects of 5 diluents--glucose-phosphate (GP), skim milk-egg yolk (MY), egg yolk-citrate (YC), blood sera (S), and seawater (SW)--on daily motility of ram sperm stored at 5°C for a short time. Ram semen collected by artificial vagina was diluted. Percentage of motile spermatozoa (PM) was assessed every 24 h up to day 10 after dilution. The different kinds of diluents except for SW had no effect on the primary motility of sperm and the primary motility was 0 with SW. There was a significant effect ( p <.01) of diluent type and storage times in the conservation rates after cooling for PM. The GP diluent achieved greater values (80.5±0.88%) than S (69.5±1.70%) and MY (78.0±1.17 %), while YC showed an intermediate value (79.0±1.24 %). In relation to time of storage, GP and YC diluents showed the PM values up to day 10, but these values were 8 and 7 days for MY and S, respectively. The GP and YC extenders maintained a PM> 50% up to day 4, while MY was greater than 50% up to day 3 and S to day 2.