Case Series of COVID-19 Asymptomatic Newborns With Possible Intrapartum Transmission of SARS-CoV-2.

Background: Despite the pandemic, data are limited regarding COVID-19 infection in pregnant women and newborns. This report aimed to bring new information about presentation that could modify precautionary measures for infants born of mothers with a remote history of COVID-19. Methods: We report two infants with possible maternofetal transmission, and four mothers without immunologic reactions. Data were collected from the patient files. Results: One mother exhibited infection signs 10 days before uncomplicated delivery, with negative RT-PCR and no antibody detection thereafter. Another mother exhibited infection 6 weeks pre-delivery, confirmed by nasopharyngeal swab testing with positive RT-PCR, and positive antibody detection (IgM and IgG). Both newborns were asymptomatic but tested positive for nasopharyngeal and stool RT-PCR at 1 and 3 days of age for the first one and at 1 day of age for stool analysis for the second one. Two additional mothers exhibited infection confirmed by positive RT-PCR testing at 28- and 31-days pre-delivery but did not present detectable antibody reaction at the time of delivery. Conclusion: These observations raise concerns regarding contamination risk by asymptomatic newborns and the efficacy of immunologic reactions in pregnant mothers, questioning the reliability of antibody testing during pregnancy.

Impact of Maternal Nutrition and Perinatal Factors on Breast Milk Composition after Premature Delivery.

(1) Background: Premature infants require mothers' milk fortification to meet nutrition needs, but breast milk composition may be variable, leading to the risk of inadequate nutrition. We aimed at determining the factors influencing mothers' milk macronutrients. (2) Methods: Milk samples were analyzed for the first five weeks after premature delivery by infrared spectroscopy. Mothers' nutritional intake data were obtained during standardized interviews with dieticians, and then analyzed with reference software. (3) Results: The composition of 367 milk samples from 81 mothers was (median (range) g/100 mL): carbohydrates 6.8 (4.4⁻7.3), lipids 3.4 (1.3⁻6.4), proteins 1.3 (0.1⁻3.1). There was a relationship between milk composition and mothers' carbohydrates intake only (r = 0.164; p < 0.01). Postnatal age was correlated with milk proteins (r = -0.505; p < 0.001) and carbohydrates (r = +0.202, p < 0.001). Multiple linear regression analyses showed (coefficient) a relationship between milk proteins r = 0.547 and postnatal age (-0.028), carbohydrate intake (+0.449), and the absence of maturation (-0.066); associations were also found among milk lipids r = 0.295, carbohydrate intake (+1.279), and smoking (-0.557). Finally, there was a relationship among the concentration of milk carbohydrates r = 0.266, postnatal age (+0.012), and smoking (-0.167). (4) Conclusions: The variability of mothers' milk composition is differentially associated for each macronutrient with maternal carbohydrate intake, antenatal steroids, smoking, and postnatal age. Improvement in milk composition could be achieved by the modification of these related factors.

Increased albuminuria in 4-year-old preterm-born children with normal height.

OBJECTIVE: To determine risk factors for high blood pressure (BP), increased markers of glomerulosclerosis, and tubular dysfunction in 4-year-old preterm-born children. STUDY DESIGN: The study group was a longitudinal cohort of 119 children with BP, albuminuria, and ß2 microglobulin measurements obtained during the neonatal period and at age 4 years. RESULTS: Systolic BP was >95(th) percentile in 15 (12.6%) of the children at age 4 years and lower in those born small for gestational age compared with those born appropriate for gestational age. Preterm-born 4-year-olds with height <-1 SD had lower systolic and diastolic BP, and 14.4% of the 4-year-olds had albuminuria. Albuminuria was less prevalent in the 4-year-olds with height <-1 SD than in those with height ≥-1 SD (6.8% vs 19.3%; P=.04). Mean albuminuria level was 1.0±0.7 mg/mmol in 4-year-olds with height <-1 SD and 1.4±1.3 mg/mmol in those with height ≥-1 SD. In multivariate analysis, albuminuria level was increased by 0.4±0.2 mg/mmol in preterm-born children with normal height at age 4, and by 0.5±0.2 mg/mmol in females, after adjustment for gestational age, sex, neonatal morbidity, and intrauterine growth restriction. These results were unchanged after adjustment for body mass index. CONCLUSION: Normal height at age 4 years may be associated with an increased risk for glomerulosclerosis in preterm-born children.

Predictive value of skin prick tests using recombinant allergens for diagnosis of peanut allergy.

BACKGROUND: Current diagnosis of peanut allergy relies on natural extracts that lack standardization. Recombinant DNA technology allows production of pure biochemically characterized proteins. Their usefulness for peanut allergy diagnosis is not established. OBJECTIVE: This study aimed to evaluate the diagnostic value of the 3 major recombinant peanut allergens. METHODS: Recombinant (r) Ara h 1, rAra h 2, and rAra h 3 were produced according to the recommendations of good manufacturing practice for recombinant allergens. Skin prick tests (SPTs) and IgE ELISA assays were performed in 30 patients with peanut allergy and 30 control subjects without food allergy: 15 nonatopic and 15 sensitized to birch pollen. Disease severity was graded by clinical scoring. RESULTS: All patients with peanut allergy showed positive SPT results to rAra h 2; 40% reacted with rAra h 1 and 27% with rAra h 3. No control subjects reacted with any of the recombinant allergens. Monosensitization to rAra h 2 was observed in 53% of patients. Neither SPT size nor levels of specific IgE were correlated with the disease severity. However, patients with monosensitization to rAra h 2 had a significantly lower severity score than polysensitized subjects and a lower level of specific IgE against peanut extract and rAra h 2. CONCLUSION: Skin prick tests to individual recombinant peanut allergens appear to be a safe and effective diagnostic tool. Cosensitization to rAra h 2 and rArah 1 and/or rAra h 3 is predictive of more severe reactions. CLINICAL IMPLICATIONS: Recombinant peanut allergens can be used by SPTs for diagnosis and evaluation of allergy severity.

Anaphylactic shock: a form of distributive shock without inhibition of oxygen consumption.

BACKGROUND: The pathophysiology of anaphylactic shock during anesthesia is incompletely characterized. It is described as distributive by analogy with septic shock (anaerobic metabolism, high tissue oxygen pressure [Ptio2] values). The Ptio2 profile and its metabolic consequences during anaphylaxis are not known. METHODS: Ovalbumin-sensitized anaphylactic shock rats (n = 11) were compared to nicardipine-induced hypotension rats (n = 12) for systemic hemodynamics, Ptio2, sympathetic nervous system activation, skeletal muscle blood flow, and interstitial lactate and pyruvate concentrations using combined microdialysis and polarographic Clark-type oxygen probes. RESULTS: In both groups, the time course and the magnitude of arterial hypotension were similar. The ovalbumin group but not the nicardipine group displayed decreased skeletal muscle blood flow (from 45 +/- 6.2 ml x 100 g(-1) x min(-1) to 24.3 +/- 5 ml x 100 g(-1) x min(-1); P < 0.0001) and Ptio2 values (from 42 +/- 5 to 5 +/- 2; P < 0.0001). The ovalbumin group had more intense sympathetic nervous system activation with higher plasma epinephrine and interstitial norepinephrine concentrations. For the ovalbumin group, there was skeletal muscle anaerobic metabolism (lactate concentration increased from 0.446 +/- 0.105 to 1.741 +/- 0.459 mm; P < 0.05) and substrate depletion (pyruvate concentration decreased from 0.034 +/- 0.01 mm to 0.006 +/- 0.002 mm; P < 0.05) leading to increased interstitial lactate/pyruvate ratios (from 17 +/- 6 to 311 +/- 115; P < 0.05). CONCLUSIONS: This profile suggests decreased skeletal muscle blood flow and oxygen delivery. Persistent energy consumption results in decreased Ptio2 and substrate depletion through anaerobic glycolysis leading to complete failure of cellular energy production. This could explain rapid organ dysfunction and resuscitation difficulties.

Early inhaled nitric oxide improves oxidative balance in very preterm infants.

Inhaled nitric oxide (iNO) improves oxygenation in premature infants, but concern has been raised about its potential oxidative toxicity. We designed this study to assess the oxidative balance in premature infants who were exposed to low dose iNO and the relationship with their clinical outcome on day 28 of life. A total of 274 infants who were <32 wk gestation were randomized at birth to receive 5 ppm of iNO if they presented with hypoxemic respiratory failure. Nonhypoxemic infants were studied as the reference group. Blood samples were withdrawn 24 h apart, within the first 4 d of life, to assess malondialdehyde (MDA) concentration as oxidative stress marker and total plasmatic glutathione (GSH), intraerythrocyte GSH peroxidase, and GSH reductase activities as antioxidant defenses. After 24 h, the rise in MDA was blunted in the iNO group compared with controls and was close to the reference infants. Conversely, GSH was more stable in the iNO group, when there was no difference for the GSH peroxidase and GSH reductase activities. On day 28, Oxygen dependence was linked with a higher increase in MDA as was the risk for death, whereas intraventricular hemorrhage was associated with a higher initial drop in GSH. Early low-dose iNO in hypoxemic preterm infants improves oxidative balance and seems to be clinically beneficial up to day 28 of life.

Relation between muscle Na+K+ ATPase activity and raised lactate concentrations in septic shock: a prospective study.

BACKGROUND: Hyperlactataemia during septic shock is often viewed as evidence of tissue hypoxia. However, this blood disorder is not usually correlated with indicators of perfusion or diminished with increased oxygen delivery. Muscles can generate lactate under aerobic conditions in a process linking glycolytic ATP supply to stimulation of Na+K+ ATPase. Using in-vivo microdialysis, we tested whether inhibition of Na+K+ ATPase can reduce muscle lactate. METHODS: In 14 patients with septic shock, two microdialysis probes were inserted into the quadriceps muscles and infused with lactate-free Ringer's solution in the absence or presence of 10(-7) mol/L ouabain, a specific inhibitor of Na+K+ ATPase. We measured lactate and pyruvate concentrations in both the dialysate fluid and arterial blood samples. FINDINGS: All patients had increased blood lactate concentrations (mean 4.0 mmol/L; SD 2.1). Lactate and pyruvate concentrations were consistently higher in muscle than in arteries during the study period, with a mean positive gradient of 1.98 mmol/L (SD 0.2; p=0.001) and 230 micromol/L (30; p=0.01), respectively. Ouabain infusion stopped over production of muscle lactate and pyruvate (p=0.0001). Muscle lactate to pyruvate ratios remained unchanged during ouabain infusion with no differences between blood and muscle. INTERPRETATION: Skeletal muscle could be a leading source of lactate formation as a result of exaggerated aerobic glycolysis through Na+K+ ATPase stimulation during septic shock. Lactate clearance as an end-point of resuscitation could therefore prove useful. RELEVANCE TO CLINICAL PRACTICE: In patients with septic shock, a high lactate concentration should be interpreted as a marker of disease, portending a bad outcome. The presence of hyperlactataemia in resuscitated septic patients should not be taken as proof of oxygen debt needing increases in systemic or regional oxygen transport to supranormal values. Lactate, instead of being regarded only as a marker of hypoxia, might be an important metabolic signal.

T cell-mediated reactions to iodinated contrast media: evaluation by skin and lymphocyte activation tests.

BACKGROUND: In addition to immediate reactions, late adverse reactions to iodinated contrast media (ICM) were reported in 2% to 5% of patients exposed to ICM and, as a consequence, have recently gained more attention. A few well-documented case reports postulate a hypersensitivity mechanism. OBJECTIVE: The aim of this study is to demonstrate a T cell-mediated mechanism to the ICM by using in vitro and ex vivo tests. METHODS: We analyzed 12 patients with 13 adverse ICM reactions, 9 of whom were women. Clinical history suggested an immune reaction to ICM. Skin tests (skin prick, intradermal, and patch tests) were performed with various ICM and read after 15 minutes and 24 and 48 hours. Skin biopsy specimens of positive test sites of 11 patients were evaluated by means of immunohistology. T-cell reactivity to ICM in vitro was analyzed with lymphocyte activation tests. RESULTS: Seven patients showed generalized maculopapular eruptions, one of them with fever; 4 had a so-called drug hypersensitivity syndrome with exanthema, eosinophilia, and fever; 1 had maculopapular eruptions and fever; 1 had late-onset urticaria with loss of consciousness; and 1 had facial edema and respiratory distress. An immune reaction to ICM was inferred from positive skin prick test (2 patients), positive patch test (10 patients), and positive intradermal test (9 patients) at 24 and 48 hours. Skin biopsy specimens revealed a T-cell infiltrate in the dermis with predominantly CD4 + T cells in 8 patients, CD8 + T cells in 1 patient, and equal numbers in 1 patient. Cross-sensitivities to several ICM were observed (9/12). Other drug allergies were noted in 6 of the 12 patients. CONCLUSIONS: Delayed reactions to ICM are most likely caused by immune reactions to these drugs and can elicit different clinical features. The involvement of T cells is suggested by positive skin test, as well as positive proliferative responses, to the drugs in vitro . A high degree of cross-reactivity with other than the eliciting ICM was observed. Moreover, 50% of these patients reported another drug hypersensitivity, suggesting a predisposition to immune reactivity in some patients.

Low-flow ischaemia has no deleterious effect on the steady-state kinetics of 201Tl and 99mTc sestamibi within myocardial tissue.

OBJECTIVES: This study aimed to specifically analyse the impact of low-flow ischaemia on the ability of myocytes to trap and accumulate Tl and sestamibi (MIBI) within myocardial tissue. METHODS: In order to reach steady-state conditions for the interstitial/cellular concentration ratios (Ci/Cc) of the tracers and thereby simulate the conditions of cell cultures studies, Tl and MIBI were injected continuously during an 80 min period within the coronary circulation of isolated hearts submitted to normoxia (n=7) or low-flow ischaemia (n=7; >50% reduction in coronary flow). Ci was determined by using interstitial microdialysis and Cc was determined from Ci and myocardial retention values of the tracers. RESULTS: At the end of the experiments, under steady-state conditions, Ci/Cc was equivalent between low-flow ischaemia and normoxia for both Tl (ischaemia, 0.60 +/- 0.25% vs normoxia, 0.63 +/-0.34%; NS) and MIBI (ischaemia, 1.00 +/- 0.68% vs normoxia, 0.76 +/- 0.32%, NS), whereas tissue concentrations of ATP were more than 4-fold lower in ischaemia than in normoxia (5.1 +/- 3.5 nmol.g vs 22.5 +/- 4.8 nmol.g; P< 0.001). CONCLUSIONS: In contrast to the published results concerning the effects of anoxia on cell cultures, low-flow ischaemia within myocardial tissue has no deleterious effects on the ability of the cells to accumulate Tl and MIBI under steady-state conditions. This gives definitive evidence of the negligible impact of cellular metabolic disorders in the decrease in Tl or MIBI uptake, which is documented by stress-SPECT within low-flow ischaemic myocardium.

Accuracy of an electrochemical sensor for measuring capillary blood ketones by fingerstick samples during metabolic deterioration after continuous subcutaneous insulin infusion interruption in type 1 diabetic patients.

OBJECTIVE: This study was designed to test the accuracy of capillary ketonemia for diagnosis of ketosis after interruption of insulin infusion. RESEARCH DESIGN AND METHODS: A total of 18 patients with type 1 diabetes treated by external pump were studied during pump stop for 5 h. Plasma and capillary ketonemia and ketonuria were determined every hour from 7:00 A.M. (time 0 min = T0) to 12:00 P.M. (time 300 min = T300). Plasma beta-hydroxybutyrate (beta-OHB) levels were measured by an enzymatic end point spectrophotometric method, and capillary beta-OHB levels were measured by an electrochemical method (MediSense Optium meter). Ketonuria was measured by a semiquantitative test (Ketodiastix). Positive ketosis was defined by a value of >/=0.5 mmol/l for ketonemia and >/=4 mmol/l (moderate) for ketonuria. RESULTS: After stopping the pump, concentrations of beta-OHB in both plasma and capillary blood increased significantly at time 60 min (T60) compared with T0 (P < 0.001), reaching maximum levels at T300 (1.30 +/- 0.49 and 1.23 +/- 0.78 mmol/l, respectively). Plasma and capillary beta-OHB values were highly correlated (r = 0.94, P < 0.0001). For diagnosis of ketosis, capillary ketonemia has a higher sensitivity and negative predictive value (80.4 and 82.5%, respectively) than ketonuria (63 and 71.8%, respectively). For plasma glucose levels >/=250 mg/dl, plasma and capillary ketonemia were found to be more frequently positive (85 and 78%, respectively) than ketonuria (59%) (P = 0.017). The time delay to diagnosis of ketosis was significantly higher for ketonuria than for plasma ketonemia (212 +/- 67 vs. 140 +/- 54 min, P = 0.0023), whereas no difference was noted between plasma and capillary ketonemia. CONCLUSIONS: The frequency of screening for ketosis and the efficiency of detection of ketosis definitely may be improved by the use of capillary blood ketone determination in clinical practice.

Effects of epinephrine and norepinephrine on hemodynamics, oxidative metabolism, and organ energetics in endotoxemic rats.

OBJECTIVE: To determine whether epinephrine increases lactate concentration in sepsis through hypoxia or through a particular thermogenic or metabolic pathway. DESIGN: Prospective, controlled experimental study in rats. SETTING: Experimental laboratory in a university teaching hospital. INTERVENTIONS: Three groups of anesthetized, mechanically ventilated male Wistar rats received an intravenous infusion of 15 mg/kg Escherichia coli O127:B8 endotoxin. Rats were treated after 90 min by epinephrine ( n=14), norepinephrine ( n=14), or hydroxyethyl starch ( n=14). Three groups of six rats served as time-matched control groups and received saline, epinephrine, or norepinephrine from 90 to 180 degrees min. Mean arterial pressure, aortic, renal, mesenteric and femoral blood flow, arterial blood gases, lactate, pyruvate, and nitrate were measured at baseline and 90 and 180 min after endotoxin challenge. At the end of experiments biopsy samples were taken from the liver, heart, muscle, kidney, and small intestine for tissue adenine nucleotide and lactate/pyruvate measurements. MEASUREMENTS AND RESULTS: Endotoxin induced a decrease in mean arterial pressure and in aortic, mesenteric, and renal blood flow. Plasmatic and tissue lactate increased with a high lactate/pyruvate (L/P) ratio. ATP decreased in liver, kidney, and heart. The ATP/ADP ratio did not change, and phosphocreatinine decreased in all organs. Epinephrine and norepinephrine increased mean arterial pressure to baseline values. Epinephrine increased aortic blood flow while renal blood low decreased with both drugs. Plasmatic lactate increased with a stable L/P ratio with epinephrine and did not change with norepinephrine compared to endotoxin values. Nevertheless epinephrine and norepinephrine when compared to endotoxin values did not change tissue L/P ratios or ATP concentration in muscle, heart, gut, or liver. In kidney both drugs decreased ATP concentration. CONCLUSIONS: Our data demonstrate in a rat model of endotoxemia that epinephrine-induced hyperlactatemia is not related to cellular hypoxia.

Induction of MnSOD gene by arachidonic acid is mediated by reactive oxygen species and p38 MAPK signaling pathway in human HepG2 hepatoma cells.

Metabolism of arachidonic acid (AA) is known to induce in different cell types an oxidative stress via the production of reactive oxygen species. As these latter may be scavenged by antioxidant enzymes as manganese and copper/zinc-dependent superoxide dismutase (MnSOD and Cu/ZnSOD, respectively), we investigated the effects of AA on their expression in human HepG2 hepatoma cells. RT-PCR and Western blot data revealed that AA induced an increase in the MnSOD, but not Cu/ZnSOD, expression at the mRNA and protein levels, respectively. This induction was also marked by an increase in MnSOD activity. The AA-induced MnSOD expression required de novo transcription as demonstrated by cotreatment of HepG2 cells with AA and actinomycin D. The fact that MnSOD expression was not induced when HepG2 cells were cultured with 5,8,11,14-eicosatetraynoic acid (ETYA), a nonmetabolizable analog of AA, or with different inhibitors of the AA metabolism pathways suggested that the metabolism of AA was required. Further investigations into the mechanisms by which AA induced MnSOD expression showed that superoxide anions released from AA metabolism act as second messengers via a signal-controlling pathway involving protein kinase C and p38 mitogen activated protein kinase (MAPK). These results define a novel role of p38 MAPK dependent-pathway in the regulation of MnSOD gene.

Effects of androgen-binding protein (ABP) on spermatid Tnp1 gene expression in vitro.

In vitro studies were designed to determine whether Sertoli cell-delivered ABP could act on spermatogenetic events, whether such an action could occur via a paracrine or a juxtacrine pathway and whether sex steroids could be involved in this action. ABP delivery to germ cells was achieved using an in vitro model based on recombinant rat ABP-producing mouse Sertoli cells cocultivated with rat spermatids. Using semi-quantitative RT-PCR, the expression of the Tnp 1 gene encoding the Transition Protein 1, involved in the histone to protamine replacement during spermatid nuclear transformation, was analyzed. Our results provide clear evidence that Sertoli cell-derived ABP acts on spermatids by modifying the TP1 mRNA level. This outcome, strictly requiring juxtacrine conditions, is obtained in the absence of sex steroid hormones. To our knowledge this is the first evidence of an effect of ABP itself on male germ cells.

Mechanisms implicated in the effects of boron on wound healing.

Recently, we demonstrated that boron modulates the turnover of the extracellular matrix and increases TNFalpha release. In the present study, we used an in vitro test to investigate the direct effect of boron on specific enzymes (elastase, trypsin-like enzymes, collagenase and alkaline phosphatase) implicated in extracellular matrix turnover. Boron decreased the elastase and alkaline phosphatase activity, but had no effect on trypsin and collagenase activities. The effect of boron on the enzyme activities was also tested in fibroblasts considered as an in vivo test. In contrast to the results obtained in vitro, boron enhanced the trypsin-like, collagenase, and cathepsin D activities in fibroblasts. Boron did not modify the generation of free radicals compared to the control and did not seem to act on the intracellular alkaline phosphatase activity, However, as it did enhance phosphorylation, it can be hypothesized that boron may affect living cells via a mediator, which could be TNFalpha whose transduction signal involves a cascade of phosphorylations.