Evolution of gene expression changes in newborn rats after mechanical ventilation with reversible intubation

Mechanical ventilation (MV) is life-saving but potentially harmful for lungs of premature infants. So far, animal models dealt with the acute impact of MV on immature lungs, but less with its delayed effects. We used a newborn rodent model including non-surgical and therefore reversible intubation with moderate ventilation and hypothesized that there might be distinct gene expression patterns after a ventilation-free recovery period compared to acute effects directly after MV. Newborn rat pups were subjected to 8 hr of MV with 60% oxygen (O(2)), 24 hr after injection of lipopolysaccharide (LPS), intended to create a low inflammatory background as often recognized in preterm infants. Animals were separated in controls (CTRL), LPS injection (LPS), or full intervention with LPS and MV with 60% O(2) (LPS + MV + O(2)). Lungs were recovered either directly following (T:0 hr) or 48 hr after MV (T:48 hr). Histologically, signs of ventilator-induced lung injury (VILI) were observed in LPS + MV + O(2) lungs at T:0 hr, while changes appeared similar to those known from patients with chronic lung disease (CLD) with fewer albeit larger gas exchange units, at T:48 hr. At T:0 hr, LPS + MV + O(2) increased gene expression of pro-inflammatory MIP-2. In parallel anti-inflammatory IL-1Ra gene expression was increased in LPS and LPS + MV + O(2) groups. At T:48 hr, pro- and anti-inflammatory genes had returned to their basal expression. MMP-2 gene expression was decreased in LPS and LPS + MV + O(2) groups at T:0 hr, but no longer at T:48 hr. MMP-9 gene expression levels were unchanged directly after MV. However, at T:48 hr, gene and protein expression increased in LPS + MV + O(2) group. In conclusion, this study demonstrates the feasibility of delayed outcome measurements after a ventilation-free period in newborn rats and may help to further understand the time-course of molecular changes following MV. The differences obtained from the two time points could be interpreted as an initial transitory increase of inflammation and a delayed impact of the intervention on structure-related genes.

Adjunctive daptomycin attenuates brain damage and hearing loss more efficiently than rifampin in infant rat pneumococcal meningitis

Exacerbation of cerebrospinal fluid (CSF) inflammation in response to bacteriolysis by beta-lactam antibiotics contributes to brain damage and neurological sequelae in bacterial meningitis. Daptomycin, a nonlytic antibiotic acting on Gram-positive bacteria, lessens inflammation and brain injury compared to ceftriaxone. With a view to a clinical application for pediatric bacterial meningitis, we investigated the effect of combining daptomycin or rifampin with ceftriaxone in an infant rat pneumococcal meningitis model. Eleven-day-old Wistar rats with pneumococcal meningitis were randomized to treatment starting at 18 h after infection with (i) ceftriaxone (100 mg/kg of body weight, subcutaneously [s.c.], twice a day [b.i.d.]), (ii) daptomycin (10 mg/kg, s.c., daily) followed 15 min later by ceftriaxone, or (iii) rifampin (20 mg/kg, intraperitoneally [i.p.], b.i.d.) followed 15 min later by ceftriaxone. CSF was sampled at 6 and 22 h after the initiation of therapy and was assessed for concentrations of defined chemokines and cytokines. Brain damage was quantified by histomorphometry at 40 h after infection and hearing loss was assessed at 3 weeks after infection. Daptomycin plus ceftriaxone versus ceftriaxone significantly (P < 0.04) lowered CSF concentrations of monocyte chemoattractant protein 1 (MCP-1), MIP-1α, and interleukin 6 (IL-6) at 6 h and MIP-1α, IL-6, and IL-10 at 22 h after initiation of therapy, led to significantly (P < 0.01) less apoptosis, and significantly (P < 0.01) improved hearing capacity. While rifampin plus ceftriaxone versus ceftriaxone also led to lower CSF inflammation (P < 0.02 for IL-6 at 6 h), it had no significant effect on apoptosis and hearing capacity. Adjuvant daptomycin could therefore offer added benefits for the treatment of pediatric pneumococcal meningitis.

Rectal paracetamol in newborn infants after assisted vaginal delivery may increase pain response

To assess the efficacy of paracetamol (acetaminophen) for neonatal pain relief.

Newborn screening for cystic fibrosis in Switzerland - Consequences after analysis of a 4 months pilot study

BACKGROUND: Switzerland introduced newborn screening (NBS) for CF in 2011, using an IRT/DNA/IRT protocol. This paper describes the results of the first year and compares two versions of the protocol with different IRT cut-offs, particularly effects on recall rate, sensitivity and specificity. METHODS: IRT cut-offs were >45ng/ml (99.0th percentile) in period 1 (months 1-4) and >50ng/ml (99.2nd percentile) in period 2 (months 5-12). In period 2 we abstained from recalls when none of the 7 most common CF mutations were detected and IRT was <60ng/ml. RESULTS: In periods 1 and 2, 26,535 and 56,663 tests were performed. Recall rates were 0.94% and 0.48%, respectively (p<0.001), PPV increased from 23% to 47% (p=0.024) and sensitivity was 90% and 100%. CONCLUSIONS: Raising initial IRT cut-off from the 99.0th to the 99.2nd percentile and abstaining from recalls for children with an IRT<60ng/ml and carrying no major CFTR mutation significantly reduced the recall rate without affecting sensitivity.

Humoral immune reaction of newborn calves congenitally infected with Neospora caninum and experimentally treated with toltrazuril

Neospora caninum is widely recognized as one of the most important infectious organisms causing abortion and stillbirth in cattle. This parasite causes severe economical losses worldwide. Infection is mostly passed vertically from mother to calf during pregnancy. Under certain circumstances, an infection can lead to abortion, but in most cases it results in a chronically infected calf, which itself will represent the next endogenously infectious generation. So far, no reliable therapeutic or metaphylactic tool has been developed. One possibility to control the problem may consist of treating newborn calves that became vertically infected by a persistently infected mother. This may allow parasite-free offspring. The aim of the present study was to address the questions: (1) can serology be used to assess efficiency of treatment in toltrazuril-medicated animals? and (2) is a strategic prevention measure possible by means of producing N. caninum-free calves from positive cows? Calves from Neospora-seropositive cows and heifers were randomly split into two different medication groups: 36 calves were medicated with toltrazuril and 36 calves obtained a placebo. Medication (20 mg toltrazuril per kg bw) was administered three times, every second day, within the 7 days post natum. Three months after medication, there was no difference in antibody reactivity between the two groups. At later time points (4-6 months), however, significant differences were found, as explained by a strong humoral immunity after chemotherapeutical affection of parasites, while the placebo-treated animals only responded weakly to the persistent infection. In summary, we concluded that (1) serology was not an entirely appropriate tool to answer our initial question and (2) toltrazuril has the potential to eliminate N. caninum in newborn calves. As a consequence, we plan to follow up toltrazuril-medicated calves clinically and serologically over a longer period and investigate if they give birth to Neospora-free calves.

Diethylhexylphthalate extracted by typical newborn lipid emulsions from polyvinylchloride infusion systems causes significant changes in histology of rabbit

Background: Looking for a candidate substance inducing hepatobiliary dysfunction under parenteral nutrition (PN) in newborns, we recently discovered that newborn infusions extract large amounts of the plasticizer diethylhexylphthalate (DEHP) from commonly used polyvinylchloride (PVC) infusion lines. This plasticizer is well known to be genotoxic and teratogenic in animals and to cause changes in various organs and enzyme systems even in humans. The aim of this study was to examine the effect of DEHP, extracted in the same way and in the same amount as in newborns, on livers of young rabbits. Methods: Prepubertal rabbits received lipid emulsion through central IV lines continuously for 3 weeks either via PVC or polyethylene (PE) infusion systems. Livers were examined after 1 and 3 weeks by light and electron microscopy. Results: By light microscopy, hydropic degeneration, single-cell necrosis, fibrosis, and bile duct proliferation were observed more in the PVC group. Electron microscopy revealed multiple nuclear changes, clusters and atypical forms of peroxisomes, proliferation of smooth endoplasmic reticulum, increased deposition of lipofuscin, and a mild perisinusoidal fibrosis only in the PVC group. These changes, which are generally regarded as reaction upon a toxic stimulus, could be exclusively attributed to DEHP. Conclusions: This investigation proved that DEHP produces toxin-like changes in livers of young rabbits in the same dose, duration, and method of administration as in newborn infants. For this reason, it is likely that DEHP is the substance that causes hepatobiliary dysfunction in newborns under PN. Possible modes of action of DEHP are proposed.

Longitudinal data on telomere length in leukocytes from newborn baboons support a marked drop in stem cell turnover around 1 year of age

Stem cells of various tissues are typically defined as multipotent cells with 'self-renewal' properties. Despite the increasing interest in stem cells, surprisingly little is known about the number of times stem cells can or do divide over a lifetime. Based on telomere-length measurements of hematopoietic cells, we previously proposed that the self-renewal capacity of hematopoietic stem cells is limited by progressive telomere attrition and that such cells divide very rapidly during the first year of life. Recent studies of patients with aplastic anemia resulting from inherited mutations in telomerase genes support the notion that the replicative potential of hematopoietic stem cells is directly related to telomere length, which is indirectly related to telomerase levels. To revisit conclusions about stem cell turnover based on cross-sectional studies of telomere length, we performed a longitudinal study of telomere length in leukocytes from newborn baboons. All four individual animals studied showed a rapid decline in telomere length (approximately 2-3 kb) in granulocytes and lymphocytes in the first year after birth. After 50-70 weeks the telomere length appeared to stabilize in all cell types. These observations suggest that hematopoietic stem cells, after an initial phase of rapid expansion, switch at around 1 year of age to a different functional mode characterized by a markedly decreased turnover rate.

Insulin-like growth factors (IGFs), IGF binding proteins, and other endocrine factors in milk: role in the newborn

The role of colostrum and milk in the neonate has been chiefly recognized as a comprehensive nutrient foodstuff. In addition, the provision of colostrum-the first milk-for early immune capacity has been well documented for several species. Colostrum is additionally a rich and concentrated source of various factors that demonstrate biological activity in vitro. Three hypotheses have been proposed for the phenotypic function of these secreted bioactive components: (1) only mammary disposal, (2) mammary cell regulation, and (3) neonatal function [gastrointestinal tract (GIT) or systemic]. Traditionally, it was assumed that the development of the GIT is preprogrammed and not influenced by events occurring in the intestinal lumen. However, a large volume of research has demonstrated that colostrum (or milk-borne) bioactive components can basically contribute to the regulation of GIT growth and differentiation, while their role in postnatal development at physiological concentrations has remained elusive. Much of our current understanding is derived from cell culture and laboratory animals, but experimentation with agriculturally important species is taking place. This chapter provides an overview of work conducted primarily in neonatal calves and secondarily in other species on the effects on neonates of selected peptide endocrine factors (hormones, growth factors, in part cytokines) in colostrum. The primary focus will be on insulin-like growth factors (IGFs) and IGF binding proteins (IGFBPs) and other bioactive peptides, but new interest and concern about steroids (especially estrogens) in milk are considered as well.

[The model project "newborn auditory screening" in the Upper Palatinate: high process and result quality of an interdisciplinary concept]

BACKGROUND: In May 2003, a newborn auditory screening program was initiated in the Upper Palatinate. METHODS: Sequential OAE- and BERA-screening was conducted in all hospitals with obstetric facilities. The Screening Center at the Public Health Authority was responsible for the coordination of the screening process, completeness of participation, the follow-up of all subjects with a positive screening test and the quality of instrumental screening. RESULTS: A total of 96% of 17,469 newborns were screened. The referral rate at discharge was 1.6% (0.4% for bilateral positive findings). For 97% of the positive screening results, a definite diagnosis to confirm or exclude hearing loss was achieved; for 43% only after intervention by the Screening Center. Fifteen children with profound bilateral hearing impairment were identified of whom eight were only detected by the intervention of the Screening Center. CONCLUSION: The effective structures established in the Upper Palatinate provide a standard for the quality of neonatal auditory screening achievable in Germany.

Severe systemic adverse reaction to proton pump inhibitors in an infant

Episodes of respiratory distress with chest retraction and wheezing, sometimes associated with facial edema, were noted after administering the proton pump inhibitors omeprazole and esomeprazole in an infant with gastroesophageal reflux. The disturbances relieved dramatically after withdrawing the proton pump inhibitor.

Functional respiratory morphology in the newborn quokka wallaby (Setonix brachyurus)

A morphological and morphometric study of the lung of the newborn quokka wallaby (Setonix brachyurus) was undertaken to assess its morphofunctional status at birth. Additionally, skin structure and morphometry were investigated to assess the possibility of cutaneous gas exchange. The lung was at canalicular stage and comprised a few conducting airways and a parenchyma of thick-walled tubules lined by stretches of cuboidal pneumocytes alternating with squamous epithelium, with occasional portions of thin blood-gas barrier. The tubules were separated by abundant intertubular mesenchyme, aggregations of developing capillaries and mesenchymal cells. Conversion of the cuboidal pneumocytes to type I cells occurred through cell broadening and lamellar body extrusion. Superfluous cuboidal cells were lost through apoptosis and subsequent clearance by alveolar macrophages. The establishment of the thin blood-gas barrier was established through apposition of the incipient capillaries to the formative thin squamous epithelium. The absolute volume of the lung was 0.02 +/- 0.001 cm(3) with an air space surface area of 4.85 +/- 0.43 cm(2). Differentiated type I pneumocytes covered 78% of the tubular surface, the rest 22% going to long stretches of type II cells, their precursors or low cuboidal transitory cells with sparse lamellar bodies. The body weight-related diffusion capacity was 2.52 +/- 0.56 mL O(2) min(-1) kg(-1). The epidermis was poorly developed, and measured 29.97 +/- 4.88 microm in thickness, 13% of which was taken by a thin layer of stratum corneum, measuring 4.87 +/- 0.98 microm thick. Superficial capillaries were closely associated with the epidermis, showing the possibility that the skin also participated in some gaseous exchange. Qualitatively, the neonate quokka lung had the basic constituents for gas exchange but was quantitatively inadequate, implying the significance of percutaneous gas exchange.

An infant mouse model of brain damage in pneumococcal meningitis

Bacterial meningitis due to Streptococcus pneumoniae is associated with an significant mortality rate and persisting neurologic sequelae including sensory-motor deficits, seizures, and impairments of learning and memory. The histomorphological correlate of these sequelae is a pattern of brain damage characterized by necrotic tissue damage in the cerebral cortex and apoptosis of neurons in the hippocampal dentate gyrus. Different animal models of pneumococcal meningitis have been developed to study the pathogenesis of the disease. To date, the infant rat model is unique in mimicking both forms of brain damage documented in the human disease. In the present study, we established an infant mouse model of pneumococcal meningitis. Eleven-days-old C57BL/6 (n = 299), CD1 (n = 42) and BALB/c (n = 14) mice were infected by intracisternal injection of live Streptococcus pneumoniae. Sixteen hours after infection, all mice developed meningitis as documented by positive bacterial cultures of the cerebrospinal fluid. Sixty percent of infected C57BL/6 mice survived more than 40 h after infection (50% of CD1, 0% of BALB/c). Histological evaluations of brain sections revealed apoptosis in the dentate gyrus of the hippocampus in 27% of infected C57BL/6 and in 5% of infected CD1 mice. Apoptosis was confirmed by immunoassaying for active caspase-3 and by TUNEL staining. Other forms of brain damage were found exclusively in C57BL/6, i.e. caspase-3 independent (pyknotic) cell death in the dentate gyrus in 2% and cortical damage in 11% of infected mice. This model may prove useful for studies on the pathogenesis of brain injury in childhood bacterial meningitis.