Congenital syphilis: A prospective study of 22 cases diagnosed by PCR

Congenital syphilis (CS) is caused by Treponema pallidum infection in utero. There is a need to develop new tools to diagnose CS: the diagnostic value of PCR is difficult to assess. The aim of this study was to describe the clinical and laboratory characteristics of mothers and infants with CS as diagnosed by PCR tests on various maternal and neonatal samples.

PATIENTS AND METHODS

We included all infants epidemiologically linked to a mother diagnosed with syphilis whose samples were referred to the Syphilis Reference Center, and for whom at least one positive PCR result was obtained.

RESULTS

Twenty-two mother-infant pairs (8.3%) with assay performed on samples from one to four different anatomic sites were included between February 2011 and April 2018. Seven mothers (31.8%) were born abroad, fifteen (68.2%) presented psychological and/or social problems, eight (36.4%) had not been screened for syphilis prior to delivery, and eleven (50%) were referred from French overseas departments or territories, or from the Paris region. Six infants (27.3%) were stillborn and six were born preterm, while fifteen infants (68.2%) presented clinical features of CS. All infants born preterm were symptomatic. Infant VDRL/RPR titer was no greater than four times that in the mother's serum, except in two cases.

DISCUSSION

Lack of antenatal care, social disadvantage and psychological issues were common. There is a need for enhanced surveillance both in the French overseas departments/territories and in the Paris region. A larger study is required to assess the sensitivity and specificity of PCR. The best site for sampling has yet to be established. We recommend the collection of as many samples as possible to avoid underdiagnosis of CS.

Thermal characterization of poly(ethylene glycol)-poly(D,L-lactide) block copolymer micelles based on pyrene excimer formation

Poly(ethylene glycol)--poly(D,L-lactide) (PEG-PDLLA) block copolymers were prepared by anionic ring-opening polymerization, resulting in block sizes effectively controlled by initial monomer/initiator ratios and low molecular weight distributions (<1.12). A pyrene derivative (1-pyrenyl carbonyl cyanide--Py) was conjugated to the end of the hydrophobic block (PDLLA) in a quantitative manner, with coupling efficiencies >95%. The so-obtained PEG-PDLLA-Py copolymers displayed fluorescent properties that were associated with the pyrene monomers, when placed in good solvents for both the hydrophilic and hydrophobic blocks. When placed in selective solvents, these copolymers self-assembled into micelles in the 30-nm range, also with low particle size distributions (<0.09), within which Py could be readily entrapped in the hydrophobic PDLLA core. Py entrapment resulted in the formation of excimers, as evident from fluorescence measurements. Observation of excimer formation/dissociation further conveyed information on the physicochemical properties of the core. Thermal characterization of these systems showed that an increase in the temperature resulted in changes in the properties of excimer fluorescence, an occurrence attributed to a higher mobility of the otherwise glassy PDLLA. This, in turn, greatly affected the inter-molecular distance between pyrene molecules, a crucial factor for excimer formation. The glass transition of the PDLLA block, approximately 38 degrees C, defined the onset for increasing chain mobility and whence excimer dissociation. Excimer fluorescence appeared to be time-dependent. Based on these observations, chain exchange processes were clearly evidenced through the time-dependent dissociation of excimers into unimers, a process that was influenced by changes in temperature.

Study of erodable paint properties involved in antifouling activity

To produce ecological marine paints, it is necessary to understand the phenomena involved in antifouling activity. Due to the multivariable components which have to be taken into account and due to their analytical intricacy, only studies based on selected properties are conceivable. In this study, four properties have been chosen, viz. erosion, biocide release, roughness and the physicochemical characteristics of the film surface. A principal-component analysis (PCA) of the experimental data has shown that, among the selected properties, only erosion affected antifouling efficiency. A more detailed investigation of erosion by quantifying global hydration and hydrolysis of immersed paints revealed the difficulty in linking the chemical structure of binders to the final erosion properties. Biocide release from paints, quantified by chromatographic methods coupled with UV detection, was inferior to the doses stated by the paint producers. These observations allowed the conceiving of formulations with reduced amounts of active molecules. The development of erodable, biodegradable binders associated with non toxic compounds is a promising way to obtain efficient antifouling paints compatible with existing, preventive systems.

[Pseudoleucopenia due to in vitro leukocyte agglutination polynuclear neutrophils: experience of a laboratory, review of the literature and future management]

Leukoagglutination is a rare EDTA-dependent phenomenon resulting in a spurious minoration of the leukocyte count performed using automated analyzers. We described seven cases. The leukocyte agglutination was detected by unstable WBC count, abnormal WBC histograms and presence of clusters of polymorphonuclears on the smear. PMN aggregates of 3 to 10 cells or bigger were observed. Discrepancies between the erroneous automated WBC count and the real count were moderate in most cases. Leukoagglutination was related to lymphoproliferative disorders, infections, alcoholic liver diseases, auto-immune diseases. Inflammatory context seemed to be requested. For few patients, the artefact occurred regardless of the type of anticoagulants (lithium heparin, buffered sodium citrate) and warming at 37 C did not always increase the WBC. Dilution in Unopette chambers was required. We confirmed that leukoagglutination of PMN was an in vitro artefact EDTA and/or temperature mediated.

Immune response in a murine model of congenital toxoplasmosis: increased susceptibility of pregnant mice and transplacental passage of Toxoplasma gondii are type 2-dependent

We used a model of acquired toxoplasmosis to study the immune response in pregnant BALB/c mice (IL-4+/+) and in pregnant transgenic IL-4-deficient BALB/c mice (IL-4-/-) during acute toxoplasmosis. Female BALB/c mice were infected orally by 20 tissue cysts of the avirulent PRU strain of Toxoplasma gondii on day 11 of pregnancy. Splenocyte cultures were used to explore proliferative responses and cytokine production in vitro. Parasite loads were determined in the lungs on day 7 post-infection and in the brain on day 30 post-infection. After infection, cultured spleen cells from pregnant mice produced more IFN-gamma (a Type I cytokine) and more NO than non pregnant mice, and the Type 2 response (IL-4 and IL-10) was weak. Although this kind of immune response may be required for mice to recover from toxoplasmosis, pregnant mice were more susceptible to infection than non pregnant mice, as illustrated by a larger parasite load in lungs and brain. Pregnant IL-4-/- mice showed lower susceptibility to T. gondii infection and a lower materno-fetal transmission rate (24% vs. 53% infected fetuses) without increased production of Type I cytokines (IFN-gamma and NO). These data indicate that Type 2 response plays an important role in increasing mouse susceptibility to T. gondii infection during pregnancy and that IL-4 and pregnancy-associated substances increase the transplacental passage of T. gondii.

[Exploration of immune response in a murine model of congenital toxoplasmosis]

We used a model of acquired toxoplasmosis to study the immune response in pregnant BALB/c mice (IL4+/+) and in pregnant transgenic IL4-deficient BALB/c mice (IL4-/-) during acute toxoplasmosis. Female BALB/c mice were infected orally by 20 tissue cysts of the avirulent PRU strain of Toxoplasma gondii on day 11 of pregnancy. After infection, cultured spleen cells from pregnant mice produced more IFN gamma (a type 1 cytokine) and more NO than non pregnant mice, and the type 2 response (IL4 and IL10) was weak. Although this kind of immune response may be required for mice to recover from toxoplasmosis, pregnant mice were more susceptible to infection than non pregnant mice, as illustrated by a larger parasite load in lungs and brain. Pregnant IL4-/- mice showed lower susceptibility to T. gondii infection and a lower materno-fetal transmission rate (24% versus 53% infected fetus) without increased production of type 1 cytokines (IFN gamma and NO). These data indicate that type 2 response plays an important role in increasing mouse susceptibility to T. gondii infection during pregnancy and that IL4 and pregnancy-associated substances increase the transplacental passage of T. gondii. This is the first time that biased towards type 2 immune response induced by pregnancy was shown to increase susceptibility to T. gondii.

Antihypertensive effect of diacetolol in essential hypertension

1 Diacetolol is the N-acetylated metabolite of acebutolol and possesses beta-adrenergic receptor blocking properties. 2 Its antihypertensive action was assessed in accordance with a double-blind randomised cross-over scheme in 17 patients with moderate essential hypertension previously well controlled with acebutolol. 3 Significant reductions in lying mean arterial blood pressure were observed with daily doses of 200 mg (- 9%), 400 mg (- 10%) and 800 mg (- 14%), and were associated with significant decreases in heart rate and plasma renin activity. 4 The diacetolol mean plasma level measured 8 to 10 h after drug ingestion was proportional to the dose (207 +/- 27, 394 +/- 63 and 823 +/- 135 ng/ml for respectively 200, 400 and 800 mg/day).