Increased risk of necrotizing enterocolitis in premature infants with patent ductus arteriosus treated with indomethacin.

OBJECTIVE: The authors evaluated the risk of necrotizing enterocolitis (NEC) in very low birth weight infants receiving indomethacin (INDO) to close patent ductus arteriosus (PDA). BACKGROUND DATA: Controversy exists regarding the best method of managing very low birth weight infants with PDA and whether to employ medical management using INDO or surgical ligation of the ductus. METHODS: Two hundred fifty-two premature infants with symptomatic PDA were given intravenously INDO 0.2 mg/kg every 12 hours x 3 in an attempt to close the ductus. Patients were evaluated for sex, birth weight, gestational age, ductus closure, occurrence of NEC, bowel perforation, and mortality. RESULTS: There were 135 boys and 117 girls. The PDA closed or became asymptomatic in 224 cases (89%), whereas 28 (11%) required surgical ligation. Ninety infants (35%) developed evidence of NEC after INDO therapy. Fifty-six were managed medically; surgical intervention was required in 34 of 90 cases (37.8%) or 13% of the entire PDA/INDO study group. Bowel perforation was noted in 27 cases (30%). Factors associated with the onset of NEC included gestational age < 28 weeks, birth weight < 1 kg, and prolonged ventilator support. The overall mortality rate was 25.5%, but was higher in infants with NEC versus those without. The highest mortality was noted in perforated NEC cases. The PDA/INDO patients were compared with a control group of 764 infants with similar sex distribution, birth weights, and gestational ages without PDA who did not receive INDO. Necrotizing enterocolitis occurred in 105 of 764 control patients (13.7%), including 13 (12.3%) with perforation. The overall mortality rate of controls was 25%, which was similar to the overall 25.5% mortality rate in the PDA/INDO study group. CONCLUSION: These data indicate that there is increased risk of NEC and bowel perforation in premature infants with PDA receiving INDO. Mortality was higher in the PDA/INDO group with NEC than those PDA/INDO infants without NEC.     

Indapamide inhibits endothelium-dependent contractions in the aorta of the spontaneously hypertensive rat

Summary— Experiments were designed to determine whether or not indapamide, an antihypertensive agent with vasodilator properties, inhibits endothelium-dependent contractions. Rings of aortae with and without endothelium from spontaneously hypertensive rats (SHR) were suspended in conventional organ chambers for the measurement of isometric force. Acetylcholine and adenosine diphosphate-β-S in the presence of a nitric oxide synthase inhibitor, caused endothelium-dependent contractions, which were inhibited by indapamide. The compound (10⁻⁴M) also slightly reduced the contractions of rings without endothelium evoked by U-46,619, which activates thromboxane-endoperoxide receptors. These results demonstrate that indapamide inhibits endothelium-dependent contractions in the SHR aorta, and suggest that the inhibition is due, at least in part, to the action of the drug on the hypertensive vascular smooth muscle.     

Laforin preferentially binds the neurotoxic starch-like polyglucosans, which form in its absence in progressive myoclonus epilepsy

Lafora disease (LD) is a fatal and the most common form of adolescent-onset progressive epilepsy. Fulminant endoplasmic reticulum (ER)-associated depositions of starch-like long-stranded, poorly branched glycogen molecules [known as polyglucosans, which accumulate to form Lafora bodies (LBs)] are seen in neuronal perikarya and dendrites, liver, skeletal muscle and heart. The disease is caused by loss of function of the laforin dual-specificity phosphatase or the malin E3 ubiquitin ligase. Towards understanding the pathogenesis of polyglucosans in LD, we generated a transgenic mouse overexpressing inactivated laforin to trap normal laforin's unknown substrate. The trap was successful and LBs formed in liver, muscle, neuronal perikarya and dendrites. Using immunogold electron microscopy, we show that laforin is found in close proximity to the ER surrounding the polyglucosan accumulations. In neurons, it compartmentalizes to perikaryon and dendrites and not to axons. Importantly, it binds polyglucosans, establishing for the first time a direct association between the disease-defining storage product and disease protein. It preferentially binds polyglucosans over glycogen in vivo and starch over glycogen in vitro, suggesting that laforin's role begins after the appearance of polyglucosans and that the laforin pathway is involved in monitoring for and then preventing the formation of polyglucosans. In addition, we show that the laforin interacting protein, EPM2AIP1, also localizes on the polyglucosan masses, and we confirm laforin's intense binding to LBs in human LD biopsy material.     

Peanut-induced anaphylaxis in children and adolescents: Data from the European Anaphylaxis Registry

Background

Peanut allergy has a rising prevalence in high-income countries, affecting 0.5%–1.4% of children. This study aimed to better understand peanut anaphylaxis in comparison to anaphylaxis to other food triggers in European children and adolescents.

Methods

Data was sourced from the European Anaphylaxis Registry via an online questionnaire, after in-depth review of food-induced anaphylaxis cases in a tertiary paediatric allergy centre.

Results

3514 cases of food anaphylaxis were reported between July 2007 - March 2018, 56% in patients younger than 18 years. Peanut anaphylaxis was recorded in 459 children and adolescents (85% of all peanut anaphylaxis cases). Previous reactions (42% vs. 38%; p = .001), asthma comorbidity (47% vs. 35%; p < .001), relevant cofactors (29% vs. 22%; p = .004) and biphasic reactions (10% vs. 4%; p = .001) were more commonly reported in peanut anaphylaxis. Most cases were labelled as severe anaphylaxis (Ring&Messmer grade III 65% vs. 56% and grade IV 1.1% vs. 0.9%; p = .001). Self-administration of intramuscular adrenaline was low (17% vs. 15%), professional adrenaline administration was higher in non-peanut food anaphylaxis (34% vs. 26%; p = .003). Hospitalization was higher for peanut anaphylaxis (67% vs. 54%; p = .004).

Conclusions

The European Anaphylaxis Registry data confirmed peanut as one of the major causes of severe, potentially life-threatening allergic reactions in European children, with some characteristic features e.g., presence of asthma comorbidity and increased rate of biphasic reactions. Usage of intramuscular adrenaline as first-line treatment is low and needs to be improved. The Registry, designed as the largest database on anaphylaxis, allows continuous assessment of this condition.

     

SspA is required for lethal Salmonella enterica serovar Typhimurium infections in calves but is not essential for diarrhea

Salmonella pathogenicity island 1 (SPI-1) encodes virulence determinants, which are important for enteropathogenicity in calves. To determine whether the Salmonella enterica serovar Typhimurium SPI-1 effector proteins SspA and SptP are important for enteropathogenicity, strains lacking these proteins were tested during oral infection of calves. Calves infected with a sptP mutant or its isogenic parent developed diarrhea and lethal morbidity. In contrast, calves infected with an sspA mutant developed diarrhea, which resolved within 10 days but did not result in mortality. The sspA mutant was recovered from bovine intestinal tissues at numbers similar to those obtained for its isogenic parent and caused marked intestinal lesions. Thus, the severity of pathological changes caused by serovar Typhimurium strains or their ability to cause diarrhea were not predictive of their ability to cause lethal morbidity in calves. We conclude that factors other than or in addition to bacterial colonization, intestinal lesions, or electrolyte loss contribute to lethal morbidity in calves infected with serovar Typhimurium.     

Identification of two new HLA alleles: B*3546* and B*5611*. How reliable are the published HLA-B intron 2 sequences?

Polymerase chain reaction-sequence-specific primer (PCR-SSP) typing for human leukocyte antigen (HLA)-B in a male 25-year-old Caucasian individual of Iranian origin and in a 42-year-old German Caucasian bone marrow donor revealed reaction patterns that did not agree with any known HLA specificity, thus suggesting in both cases the existence of a novel allele. Sequence-based typing (SBT) after allelic separation revealed the sequences of the new alleles HLA-B*5611 and B*3546. The sequence patterns of both new alleles might have been generated as the results of double crossing over, possibly over several generations. During the analysis of the HLA-B*3546 intron 2 sequence for possible crossing over points, a base insert, an additional G after position 700, was found. This insert was analyzed using SBT and PCR-SSP and was found to be present not only in all samples carrying B*35, but also in all HLA-B specificities tested. It appears that all known HLA-B alleles may contain a G insert at position 700 of intron 2, and that the published intron 2 sequence alignments of the HLA-B locus may contain errors at this position.     

Variable number of tandem repeats in clinical strains of Haemophilus influenzae.

An algorithm capable of identifying short repeat motifs was developed and used to screen the whole genome sequence available for Haemophilus influenzae, since some of these repeats have been shown to affect bacterial virulence. Various di- to hexanucleotide repeats were identified, confirming and extending previous findings on the existence of variable-number-of-tandem-repeat loci (VNTRs). Repeats with units of 7 or 8 nucleotides were not encountered. For all of the 3- to 6-nucleotide repeats in the H. influenzae chromosome, PCR tests capable of detecting allelic polymorphisms were designed. Fourteen of 18 of the potential VNTRs were indeed highly polymorphic when different strains were screened. Two of the potential VNTRs appeared to be short and homogeneous in length; another one may be specific for the H. influenzae Rd strain only. One of the primer sets generated fingerprint-type DNA banding patterns. The various repeat types differed with respect to intrinsic stability as well. It was noted for separate colonies derived from a single clinical specimen or strains passaged for several weeks on chocolate agar plates that the lengths of the VNTRs did not change. When several strains from different patients infected during an outbreak of lung disease were analyzed, increased but limited variation was encountered in all VNTR sites analyzed. One of the 5-nucleotide VNTRs proved to be hypervariable. This variability may reflect the molecular basis of a mechanism used by H. influenzae bacteria to successfully colonize and infect different human individuals.     

Mutational analysis of the SOX9 gene in campomelic dysplasia and autosomal sex reversal: lack of genotype/phenotype correlations

It has previously been shown that, in the heterozygous state, mutations in the SOX9 gene cause campomelic dysplasia (CD) and the often associated autosomal XY sex reversal. In 12 CD patients, 10 novel mutations and one recurrent mutation were characterized in one SOX9 allele each, and in one case, no mutation was found. Four missense mutations are all located within the high mobility group (HMG) domain. They either reduce or abolish the DNA-binding ability of the mutant SOX9 proteins. Among the five nonsense and three frameshift mutations identified, two leave the C-terminal transactivation (TA) domain encompassing residues 402-509 of SOX9 partly or almost completely intact. When tested in cell transfection experiments, the recurrent nonsense mutation Y440X, found in two patients who survived for four and more than 9 years, respectively, exhibits some residual transactivation ability. In contrast, a frameshift mutation extending the protein by 70 residues at codon 507, found in a patient who died shortly after birth, showed no transactivation. This is apparently due to instability of the mutant SOX9 protein as demonstrated by Western blotting. Amino acid substitutions and nonsense mutations are found in patients with and without XY sex reversal, indicating that sex reversal in CD is subject to variable penetrance. Finally, none of 18 female patients with XY gonadal dysgenesis (Swyer syndrome) showed an altered SOX9 banding pattern in SSCP assays, providing evidence that SOX9 mutations do not usually result in XY sex reversal without skeletal malformations.