Predictive performance of PAMG-1 vs fFN test for risk of spontaneous preterm birth in symptomatic women attending an emergency obstetric unit: retrospective cohort study.

OBJECTIVE: To compare the performance of the placental alpha microglobulin-1 (PAMG-1) and fetal fibronectin (fFN) tests for the prediction of spontaneous preterm delivery in patients presenting to an emergency obstetric unit with threatened preterm labor, by conducting a retrospective audit of patient medical records from separate 1-year periods during which either fFN or PAMG-1 was used as the standard-of-care biochemical test. METHODS: This was a retrospective cohort study based on chart review of electronic medical records of women with threatened preterm labor presenting at a level-III maternity hospital over two different periods: (1) the 'baseline' period (year 2012), during which the qualitative fFN test with a cut-off of 50 ng/mL was used as the standard-of-care biochemical test for the risk assessment of preterm delivery, and (2) the 'comparative' period (year 2016), during which the PAMG-1 test with a cut-off of 1 ng/mL was used as the standard-of-care biomarker test. Patients with a singleton pregnancy between 24 + 0 and 34 + 6 weeks' gestation with symptoms of early preterm labor, clinically intact membranes and cervical dilatation < 3 cm, who did not have a medically indicated preterm delivery within 14 days of testing, were selected for chart review and included in the analysis. Key parameters used for the analysis were biochemical test results, time of testing and time of delivery. Positive predictive value (PPV), negative predictive value (NPV), sensitivity, specificity, and positive and negative likelihood ratios (LR+ and LR-) for the prediction of spontaneous preterm delivery ≤ 7 and ≤ 14 days of presentation were calculated for the PAMG-1 and fFN tests. RESULTS: Four hundred and twenty patients were identified as having presented with threatened preterm labor during the baseline period, of whom 378 (90.0%) met the eligibility criteria. Of these, 38 (10.1%) were fFN positive and 10 (2.6%) had spontaneous preterm delivery ≤ 7 days of presentation. PPV, NPV, LR+ and LR- of fFN were 7.9%, 97.9%, 3.2 and 0.8, respectively, for spontaneous preterm delivery ≤ 7 days. Four hundred and ten patients were identified as having presented with threatened preterm labor during the comparative period and 367 (89.5%) subjects met the eligibility criteria. Of these, 17 (4.6%) were PAMG-1 positive and 12 (3.3%) had spontaneous preterm delivery ≤ 7 days of presentation. PAMG-1 PPV and NPV were 35.3% and 98.3%, respectively, and LR+ and LR- were 16.1 and 0.5, respectively, for spontaneous preterm delivery ≤ 7 days. CONCLUSIONS: Before switching to PAMG-1, fFN was the standard-of-care test for the risk assessment of spontaneous preterm delivery. This retrospective audit of each test's performance over separate 1-year periods shows that we were more than twice as likely to get a positive fFN test than a positive PAMG-1 test, while the rate of discharging women who ultimately delivered spontaneously within 14 days of testing was not affected. Furthermore, a positive PAMG-1 test was more than four times more reliable than a positive fFN test in predicting imminent spontaneous preterm delivery. The use of a more reliable biomarker that is associated with fewer false-positive results could lead to a reduction in unnecessary admissions, interventions and use of hospital resources. Copyright © 2017 ISUOG. Published by John Wiley & Sons Ltd.

Canal switch and re-entry phenomenon in benign paroxysmal positional vertigo: difference between immediate and delayed occurrence.

This prospective study was designed to evaluate the differences between immediate and delayed canal re-entry of otoliths after therapeutic manoeuvres in patients with benign paroxysmal positional vertigo (BPPV). A total of 196 patients with BPPV were visited and 127 matched our inclusion criteria. The mean age was 54.74 years. The horizontal semicircular canal (HSC) was involved in 30 cases and the posterior semicircular canal (PSC) in 97 patients. Patients with hearing loss in the ear affected by BPPV have a more recurrent form, compared to those with normal hearing. An immediate canal re-entry was recorded in 3 patients with HSC BPPV, all with geotropic nystagmus. In 7 patients with PSC BPPV, the immediate canal re-entry was detected and the delayed form was noted in 5 patients. The patients with the delayed canal re-entry underwent more than 2 previous manoeuvres. The canal re-entry was not related to the manoeuvre performed. The timing of the Dix-Hallpike test to verify the resolution of the BPPV had a significant role in immediate canal re-entry. A recurrence in the follow-up at least one month after treatment was recorded in 20 patients and was more frequent in patients that had canal re-entry. The canal re-entry or canal switch is a clinical entity that should be kept in mind of the neurotologist when approaching BPPV patients. It is important to distinguish it from recurrence when delayed and from manoeuvre failure when immediate. The timing of manoeuvre performing, in particular the final verification test after therapeutic sessions, is important to prevent the immediate reflux of particles into canals.

A duplicated nitrotienyl derivative with antimycobacterial activity: synthesis, X-ray crystallography, biological and mutagenic activity tests.

A duplicated nitrotienyl derivative was obtained as a by-product from the synthesis of a proposed molecular hybrid of a nitrotienyl derivative and isoniazid with an expected dual antimycobacteria mechanism. The structure was shown to be the 5,5'-dinitro-2-(2,3-diaza-4-(2'-tienyl)buta-1,3-dienyl)tiophene by X-ray crystallography. The minimal inhibitory concentration (MIC) determination of this compound proved to be promising against Mycobacterium pathogenic strains such as M. avium and M. kansasii, although it had a high level of mutagenicity, as observed in mutagenic activity tests.

Nickel availability and urease expression in Proteus mirabilis.

Cells of Proteus mirabilis, previously grown in nutrient broth (NB), exhibited an increase in urease activity during subsequent incubation in mineral medium even when protein biosynthesis was inhibited. During growth in NB, degradation of amino acids obviously led to the formation of nickel-complexing metabolites, and nickel ions were therefore unavailable for maximal expression of enzymatically active urease; this inhibition of urease biosynthesis was overcome by the addition of nickel to the growth medium, and also by added glucose. Experiments concerning the incorporation of radioactive nickel into urease finally indicated that the observed increase in urease activity was caused by posttranslational insertion of nickel into performed apo-urease.