Improved deferred antagonism technique for detecting antibiosis.

The deferred antagonism technique has been utilized for several decades for detecting antibiosis activity. Most protocols require the elimination of antibiotic-producing cells by exposing them to chloroform vapour, UV radiation or filter sterilizing the filtrate steps that require additional time and expense to complete. We provide a modified approach to current soft agar overlay practices, which involves addition of antibiotics to the soft agar overlay to inhibit growth of the producer but not the indicator strain. This technique can be used to reproducibly and efficiently screen for antibiotic production with ease. We demonstrate the effectiveness of this technique with three bacterial systems: inhibition of the bacterial spot of tomato pathogen, Xanthomonas euvesicatoria, by its pathogenic competitor Xanthomonas perforans; and inhibition of the fire blight pathogen, Erwinia amylovora, by Pantoea vagans C9-1 or Pseudomonas fluorescens A506. SIGNIFICANCE AND IMPACT OF THE STUDY: Deferred antagonism assays are used commonly to observe antibiotic production by micro-organisms. Killing or removing the producer cells prior to introduction of the indicator strain is a standard practice but requires additional time and special handling procedures. We evaluated a modification of the assay, where the overlay medium is amended with an antibiotic to which the indicator strain is resistant and the producer strain is sensitive. This modification obviates extra steps to kill the producer strain prior to overlaying with the indicator strain and provides a rapid, consistent and cost-effective method to detect antibiosis.

Impact of early screening echocardiography and targeted PDA treatment on neonatal outcomes in "22-23" week and "24-26" infants.

The hemodynamically significant patent ductus arteriosus (hsPDA) is a controversial topic in neonatology, particularly among neonates at the earliest gestational ages of 22+0-23+6 weeks. There is little, to no data on the natural history or impact of the PDA in extremely preterm babies. In addition, these high-risk patients have typically been excluded from randomized clinical trials of PDA treatment. In this work, we present the impact of early hemodynamic screening (HS) of a cohort of patients born 22+0-23+6 weeks gestation who either were diagnosed with hsPDA or died in the first postnatal week as compared to a historical control (HC) cohort. We also report a comparator population of 24+0-26+6 weeks gestation. All patients in the HS epoch were evaluated between 12-18h postnatal age and treated based on disease physiology whereas the HC patients underwent echocardiography at the discretion of the clinical team. We demonstrate a two-fold reduction in the composite primary outcome of death prior to 36 weeks or severe BPD and report a lower incidence of severe intraventricular hemorrhage (n=5, 7% vs n=27, 27%), necrotizing enterocolitis (n=1, 1% vs n=11, 11%) and first-week vasopressor use (n=7, 11% vs n=40, 39%) in the HS cohort. HS was also associated with an increase in survival free of severe morbidity from the already high rate of 50% to 73% among neonates <24 weeks gestation. We present a biophysiological rationale behind the potential modulator role of hsPDA on these outcomes and review the physiology relevant to neonates born at these extremely preterm gestations. These data highlight the need for further interrogation of the biological impact of hsPDA and impact of early echocardiography directed therapy in infants born less than 24 weeks gestation.

Best practice recommendations: ENT consultations during the COVID-19 pandemic.

These best practice recommendations for ENT consultations during the COVID-19 pandemic have been drawn up because ENT examinations and treatments are at risk of contamination by the SARS-Cov-2 virus in certain instances. Thus, ENT specialists are among the professionals who are most exposed to this infection. During the pandemic, insofar as an asymptomatic patient may be infected and contagious, the same precautions must be employed whether the patient is ill with, suspected of having, or without any clinical evidence of COVID-19 infection. According to the scientific data available, the examinations and procedures potentially exposing to projections/aerosolizations of organic material of human origin are considered to be at risk of staff contamination. For ENT examinations and procedures without exposure to such projections/aerosolizations, the professional is advised to a long sleeve clean outfit, a surgical mask and gloves in case of contact with the patient's mucosa. ENT examinations and procedures with exposure to these projections/aerosolizations require the so-called "airborne", "contact", and "droplets" additional precautions: FFP2/N95 respiratory protection device, eye protection, disposable headwear and long sleeve overgown.

Androgen regulation of epidermal growth factor receptor binding activity during fetal rabbit lung development.

Fetal lung development progresses in a sex-specific manner with male fetuses exhibiting delayed maturation. Androgens, both exogenous and endogenous, inhibit while epidermal growth factor (EGF) enhances fetal lung development. We hypothesized that one mechanism responsible for the delay in male fetal lung development is an androgen-induced delay in EGF receptor binding activity. We measured EGF binding in sex-specific fetal rabbit lung plasma membranes isolated from control fetuses (days 21, 23, 25, 27, 29, and 30 of gestation) and from androgen-treated fetuses (days 21, 23, and 27 of gestation) that had been continuously exposed in vivo to exogenous 5 alpha-dihydrotestosterone from day 12 through 27 of gestation. Specific binding of EGF was significantly lower in male than in female fetal lung tissue isolated from controls at day 21 of gestation. Scatchard analysis revealed that this decrease in EGF binding was associated with decreased EGF receptor density without any significant change in affinity. Prenatal exogenous androgen treatment led to decreased EGF binding in fetal rabbit lung tissue from both sexes secondary to a decrease in EGF receptor density. These findings suggest that one mechanism responsible for the delay in male fetal lung maturation is an androgen-induced delay in EGF receptor binding activity during fetal lung development.

Congenital hypothyroidism with delayed thyroid-stimulating hormone elevation in premature infants born at less than 30 weeks gestation.

OBJECTIVE: Congenital hypothyroidism (CH) with delayed thyroid-stimulating hormone (TSH) elevation is a common form of thyroid dysfunction among premature infants. Routine newborn screening (NBS) may miss infants with CH with delayed TSH elevation. The objective of the study is to determine the prevalence of CH with delayed TSH elevation in premature infants and to identify associated risk factors. STUDY DESIGN: Retrospective analysis of serum thyroid function screening (TFS) at day of life 30 in premature infants <30 weeks gestation, admitted to University of Iowa Neonatal Intensive Care Unit between 1 July 2012 to 30 June 2015. Serum free thyroxine and TSH levels were obtained in premature infants <30 weeks gestation on day of life 30. Follow-up testing and pediatric endocrinology consultation were done according to the institutional protocol. RESULT: In total, 286 infants were included. All infants underwent routine NBS and 280 patients underwent TFS. Twenty-six patients (9.1%) were diagnosed with thyroid dysfunction. NBS identified only three patients. CH with delayed TSH elevation was diagnosed in 20 patients (6.9%) and was significantly associated with multiple gestation, lower birth weight, higher gestational age and lower 5 min APGAR score. CONCLUSION: Thyroid dysfunction is common among premature infants born before 30 weeks gestation. The majority of cases with thyroid dysfunction had CH with delayed TSH elevation, which was not detected by NBS. We recommend measurement of serum TSH and free T4 levels on day of life 30 in premature infants born at <30 weeks gestation to identify patients with CH with delayed TSH elevation.

Repeat surfactant therapy for postsurfactant slump.

OBJECTIVE: To evaluate repeat surfactant therapy for the treatment of respiratory failure associated with postsurfactant slump in extremely low birth weight infants (ELBW) by characterizing the population of premature infants who develop postsurfactant slump and measuring their response to a secondary course of surfactant therapy. STUDY DESIGN: A retrospective analysis of a cohort of all patients admitted over a 3-year period with birth weights <1000 g (ELBW infants). Information was collected by chart review and the patients were categorized into three distinct groups for analysis. Initial surfactant only, patients who received surfactant replacement therapy only for respiratory distress syndrome (RDS); repeat surfactant, patients who received both initial surfactant replacement for RDS and repeat surfactant therapy for postsurfactant slump (defined as respiratory failure after 6 days of age), and no surfactant, patients in whom no surfactant was ever administered. A respiratory severity score (RSS) was used to measure the severity of lung disease and response to surfactant therapy. RESULTS: Over 3 years, there were 165 ELBW infants who could develop postsurfactant slump and be eligible for repeat surfactant therapy. There were 39 infants who never received any surfactant therapy estimated gestational age (EGA) 27.7 +/- 1.7, birth weight 856 +/- 109 g) either at birth or after 6 days of life. There were 126 patients treated for RDS with initial surfactant replacement therapy (EGA 25.6 +/- 1.9 weeks, birth weight 713 +/- 179 g). Out of these RDS patients, 101 improved with an initial course of surfactant therapy (EGA 26 +/- 1.8, birth weight 751 +/- 143 g), but 25 (20% of the patients with RDS) developed postsurfactant slump and received a repeat course of surfactant therapy (EGA 24.7 +/- 1.2, birth weight 647 +/- 120 g). The repeat surfactant group (postsurfactant slump) was significantly more premature and had significantly lower birth weights compared to both the initial surfactant only group and the no surfactant ever group. Logistic regression analysis revealed that lack of antenatal steroids, earlier gestational age, and the receiving of 2 or more doses of surfactant to treat the initial RDS were significantly associated with receiving repeat surfactant therapy for postsurfactant slump. Of the 25 patients treated with a repeat course of surfactant therapy more than 70% of patients (n = 18) had an improvement in their lung disease with a 15% reduction in their RSS. This improvement was significant at all time points evaluated (12, 24, and 48 h). CONCLUSION: We found that a repeat course of surfactant therapy, after day of life 6, led to a significant improvement in hypoxemic respiratory failure in premature infants with postsurfactant slump. Infants who received repeat surfactant therapy were born at a significantly earlier gestational age, had significantly smaller birth weight and had significantly worse lung disease. They were significantly less likely to have received antenatal steroids and were significantly more likely to have received multiple doses of surfactant to treat their initial RDS. A repeat course of surfactant therapy for patients with postsurfactant slump appeared beneficial in the short-term. These initial findings would support performing randomized control trials of repeat surfactant therapy for postsurfactant slump.

Inhibition of tyrosine kinase activity decreases expression of surfactant protein A in a human lung adenocarcinoma cell line independent of epidermal growth factor receptor.

Epidermal growth factor (EGF) enhances fetal lung development in vivo and in vitro. Ligand binding to the EGF receptor stimulates an intrinsic receptor tyrosine kinase initiating a signal transduction cascade. We hypothesized that blocking EGF receptor function with tyrosine kinase inhibitors would decrease the expression of surfactant protein A in human pulmonary epithelial cells. Human pulmonary adenocarcinoma cells (NCI-H441) were exposed to genistein (a broad range inhibitor of tyrosine kinases) and tyrphostin AG1478 (a specific inhibitor of EGF receptor tyrosine kinase). Genistein significantly decreased surfactant protein A (SP-A) and SP-A mRNA levels in H441 cells without affecting cell viability. The inhibitory effect of genistein on SP-A content was reversible. In contrast, tyrphostin AG1478 had no effect on SP-A levels despite a greater inhibitory effect than genistein on EGF receptor tyrosine autophosphorylation. Furthermore, treatment of H441 cells with exogenous EGF did not increase SP-A content or mRNA levels beyond baseline. We conclude that inhibition of tyrosine kinase activity other than the EGF receptor decreases the expression of surfactant protein A at a pretranslational level in human pulmonary adenocarcinoma cells. These results suggest the importance of tyrosine kinases in modulating human SP-A synthesis.

Sex-specific differences in rabbit fetal lung maturation in response to epidermal growth factor.

Males and females exhibit different stages of lung development at the same gestation with males lagging behind. We hypothesized that one of the mechanisms responsible for the sex-specific difference in fetal lung maturation is a delay in the onset of epidermal growth factor (EGF) activity in the male fetal lung. EGF influences growth and differentiation during development. We studied the effects of EGF on the incorporation of glycerol into lamellar body disaturated phosphatidylcholine (DSPC) in sex-specific fetal rabbit lung explants prepared at 21 and 24 days gestation (term 31 days). The explants were maintained in Waymouth's media + 10% stripped fetal calf serum with or without EGF (10 ng/ml). The incorporation of [1,3-14C]glycerol into lamellar body DSPC was assessed after 3, 5, or 7 days of culture. Female lung explants prepared at 21 days of gestation had increased incorporation of glycerol into DSPC over time in response to EGF treatment. Male lung explants prepared at 21 days did not respond to EGF treatment. In explants prepared at 24 days gestation, baseline glycerol incorporation into DSPC was higher in female as compared to male fetal lung explants. EGF-responsiveness was also sex-specific in these more mature explants, with the male explants now responding to EGF with a consistent increase in the incorporation of glycerol into lamellar body DSPC. We conclude that one of the mechanisms responsible for the lag in male fetal lung development is a delay in the onset of EGF activity.

Molecular cloning of crustacean putative molt-inhibiting hormone (MIH) precursor.

A cDNA encoding the complete precursor of the putative molt-inhibiting hormone (MIH) of the shore crab, Carcinus maenas, was isolated and sequenced. The precursor consists of a putative 35 amino acid signal peptide and the 78 amino acid mature MIH. The deduced MIH amino acid sequence is in complete agreement with the sequence previously determined by Edman degradation. In situ hybridization revealed MIH-expression in a subpopulation of large neurosecretory perikarya of the medulla terminalis X-organ in the eyestalk.

Structure and localization of mRNA encoding a pigment dispersing hormone (PDH) in the eyestalk of the crayfish Orconectes limosus.

The pigment-dispersing hormone (PDH) is produced in the eyestalks of Crustacea where it induces light-adapting movements of pigment in the compound eye and regulates the pigment dispersion in the chromatophores. To study this hormone at the mRNA level, we cloned and sequenced cDNA encoding PDH in the crayfish Orconectes limosus. The structure of the PDH preprohormone consists of a signal peptide, a PDH precursor-related peptide (PPRP) and the highly conserved PDH peptide at the carboxy-terminal end. In situ hybridization in combination with immunocytochemistry revealed four cell clusters expressing PDH in the optic ganglia of the eyestalk. Three clusters stained both with the PDH cRNA probe and the PDH antiserum, however, the perikarya in the lamina ganglionaris (LG) only stained with the PDH antiserum, suggesting the presence of a PDH-like peptide in the LG.

Outcome of infants with birth weights less than 1000 g with respiratory distress syndrome treated with high-frequency ventilation and surfactant replacement therapy.

OBJECTIVE: To compare outcomes in premature infants with respiratory distress syndrome who received surfactant replacement therapy and were treated with either high-frequency or conventional mechanical ventilation. DESIGN: Retrospective chart review of patient series. SETTING: Tertiary academic medical center. PATIENTS: One hundred fourteen extremely low-birth-weight infants (< 1000 g) with respiratory distress syndrome treated with surfactant replacement therapy, consecutively admitted to the neonatal intensive care unit between September 1989 and August 1992. INTERVENTIONS: Treatment with either high-frequency ventilation (n = 46) or conventional mechanical ventilation (n = 68) after surfactant replacement therapy. MAIN OUTCOME MEASURES: Intraventricular hemorrhage and neurodevelopmental status. RESULTS: Infants who received high-frequency ventilation had significantly lower birth weights and were more premature than infants receiving conventional mechanical ventilation. Despite this, patients ventilated with high frequency had similar incidences of intraventricular hemorrhage and impaired neurodevelopmental outcomes when compared with the conventionally ventilated patients. As expected, the smaller and more premature infants receiving high-frequency ventilation required a longer duration of respiratory support (mechanical ventilation and nasopharyngeal continuous positive airway pressure). Additionally, multiple logistic regression analysis to control for differences in birth weight and gestational age between the two groups revealed a significant association between the combined use of high-frequency ventilation and antenatal corticosteroids and the absence of either intraventricular hemorrhage or pneumothorax. CONCLUSION: We conclude that high-frequency ventilation combined with surfactant therapy is as safe as conventional mechanical ventilation combined with surfactant therapy for treating respiratory distress syndrome in extremely low-birth-weight infants (< 1000 g) and does not increase the risk of either intraventricular hemorrhage or abnormal neurodevelopmental outcome.

Syllabic effects in word processing: evidence from the structural induction paradigm.

Spoken words have a rich structural organization in memory, consisting of syllabic and subsyllabic representations. A phoneme monitoring paradigm, in which the target phoneme occurs more frequently in one syllabic position than another (e.g., onset of the 2nd syllable vs. the coda of the 1st syllable: neu-tral vs. nut-meg; C. Pallier, N. Sebastian-Galles, T. Felguera, A. Christophe, & J. Mehler, 1993) was used to explore the formation of syllabic structure during word processing. Experiment 2 investigated how a recognition system that uses syllabic structure processes words with unclear syllable boundaries (e.g., pa-lace or pal-ace?). Two methodological issues were explored: The importance of a baseline condition for measuring effects of induction (Experiment 1) and the form of the representation used in the induction paradigm (Experiment 3). Findings suggest that syllabic structure begins to form early in word processing, and they demonstrate the adequacy of the induction procedure for measuring such processes.

Neonatal morbidity and mortality secondary to premature rupture of membranes.

PROM is one of the most common complications of pregnancy that has a major impact on neonatal mortality and morbidity. The occurrence of PROM is either directly or indirectly responsible for a large number of premature births and the concomitant mortality and morbidity associated with preterm delivery. PROM turns a pregnancy into a high-risk situation and increases the need for neonatal resuscitation in the delivery room. The incidence of neonatal sepsis increases with PROM, but the overall outcome of the neonate, even with surfactant therapy, is still primarily dependent on the gestational age at the time of delivery. This is most relevant between 24 and 27 weeks' gestation. During this 3-week interval, survival improves by almost 2% for each additional day of in utero maturation (i.e., from 35 to 75%). Thus the benefit to the fetus of prolonging the pregnancy in cases of PROM is immensely worthwhile and should be aggressively pursued as long as there is no significant increase in maternal morbidity.

[Embolic intracardiac thrombosis on a catheter for permanent stimulation. An echocardiographic finding]. / Thrombose intracardiaque emboligène sur sonde de stimulation permanente. Une découverte échocardiographique.

If endovenous thromboses on permanent cardiac stimulation catheter are rather frequent, it is usual to note the absence of complications, especially embolic complications. On the contrary, intracardiac thromboses, occurring always on a permanent stimulation catheter, are rare but may generate embolisms: the authors report a new case discovered on bidimensional sonocardiography recorded following pulmonary embolisms.

[Flecainide by the intravenous route: a new method for decreasing auricular fibrillation]. / Le flécaïnide par voie intraveineuse: une nouvelle méthode de réduction de la fibrillation auriculaire.

The action of intravenous flecainide was studied in patients presenting a tachyarrhythmia secondary to a permanent atrial fibrillation of recent onset. We obtained 9 improvements in 15 patients included in the protocol which consisted in the intravenous injection of 2 mg/kg of flecainide in 10 minutes. The side effects were minimal: no sign of cardia insufficiency nor alteration of the arterial blood pressure was noted. Nevertheless, although interesting, this method to decrease atrial fibrillation is not, in our opinion, destined to replace external electrical shock, except in some special cases.

[Myocardiopathies of Friedreich's disease]. / Les myocardiopathies de la maladie de Friedreich.

Cardiac involvement in Friedreich's disease is classically a hypertrophic myocardiopathy, concentric or assymmetrical with or without dilatation. It has nothing specific in comparison to other myocardiopathies. Nevertheless, forms with a dilated myocardiopathy are also possible, but much more unfrequent. A propos of three cases, we have studied the different aspects of myocardiopathies in Friedreich's ataxia. The problem raised by the case of an hypertrophic myocardiopathy evolving toward a dilated form, unusual element of this pathology, is presented. The therapeutic potential of hypertrophic myocardiopathies is classically represented either by beta-blockers or by the more recent slow calcium inhibitors.

[Residual arterial hypertension after excision of an extra-adrenal pheochromocytoma]. / Hypertension artérielle résiduelle après exérèse d'un phéochromocytome extra-surrénalien.

Residual arterial hypertension after excision of a pheochromocytoma of the Zuckerkandl organ, has brought the problem of its etiology. The short term approach consisted in performing, after specific biochemical dosages, a scintigram with IMBG, a scan and a magnetic resonance imaging, to look for a second pheochromocytoma. A negative workup enabled to conclude to an essential arterial hypertension. Nevertheless, this does not exclude the possibility of a long term malignancy, requiring clinical monitoring and IMBG scintigraphy.

[Arboviruses in Iran (author's transl)]. / Arbovirus en Iran.

During an entomological survey conducted in april-june 1978 in the province of Khorassan in the eastern part of Iran, ixodid and argasid ticks were collected for arbovirus research. Five serotypes of arboviruses were obtained: Quaranfil, Thogoto, Wad Medani, Wanowrie and Crimean Haemorrhagic Fever-Congo. The isolation of all these arboviruses is reported for the first time in Iran.

[Clinical case of the month. Myoclonic-astatic epilepsy in a young child (MAE) or Doose syndrome]. / Le cas clinique du mois. Epilepsie myoclono-astatique du jeune enfant (EMA) ou syndrome de Doose.

Myoclonic astatic epilepsy (MAE) belongs to the epilepsies with generalized seizures. MAE occurs in 1-2% of all childhood epilepsies up to age 9. This disease is characterized by various clinical and EEG criteria. The course of this epileptic syndrome is variable but influenced by an early diagnosis and by a specific treatment.

[Unusual cause of digestive hemorrhage in chronic hemodialysis patients: splenic aneurysm with arteriovenous fistula]. / Une cause exceptionnelle d'hémorragies digestives chez l'hémodialysé chronique: l'anévrysme splénique, avec communication artério-veineuse.

A 45 years old woman, hemodialysed since 1981, with an history of Staphylococcal septicemia in may 1983, is admitted in emergency room in may 1984 for massive gastro intestinal bleeding. After oesogastro fibroscopy suspecting duodenal ulcer, because continuous and recurrent bleeding, a laparotomy find only symptoms of portal hypertension (ascites, venous dilatation on abdominal oesophagus and stomach). The ligation of this venous dilatations stop temporarily the gastro intestinal bleeding. But recurrence of this bleeding conduct to a celiac angiography discovering a splenic aneurysm with arterio venous fistula. The surgical treatment of this aneurysm can stop the gastro intestinal bleeding. Histopathologic observation of this aneurysm can suspect an infectious origin.