Antidepressants and recurrence of depression in the postpartum period.

To examine postpartum recurrence rates of depression comparing women receiving antidepressant treatment to women not being treated with psychotropic medication. This was a prospective study of 130 women with major depressive disorder (MDD) who attended a tertiary care perinatal clinic during and after pregnancy. Depression recurrence was defined as a score of 13 or more on the Edinburgh Postnatal Depression Scale (EPDS) or a score of greater than 13 on the Hamilton Depression Rating Scale (HDRS). Over half of women (56.9%) were not receiving medication during pregnancy to treat their mood disorder, with the rate of medication use increasing over the 1-year postpartum period. When comparing women being treated with antidepressant medication (monotherapy or combination therapy) to women receiving no psychotropic medication, no significant differences in recurrence rates were observed during the postpartum period. However, we did observe that the occurrence of depression in our sample fluctuated between rates comparable to general population estimates to rates that were at times more than twofold higher, regardless of treatment with antidepressant medication. The findings of this study align with research which suggests that the postpartum period is a particularly vulnerable time for recurrence of depression. Moreover, our results suggest that this remains the case regardless of antidepressant treatment.

Thermodynamic driving forces for PAH isomerization and growth during thermal treatment of polluted soils.

For a limiting case of thermodynamic equilibrium, the importance of two classes of thermal chemical reactions that modify the structure and bioactivity of polycyclic aromatic hydrocarbons (PAH) was assessed computationally. These reactions are molecular weight (MW) growth by acetylene addition, and intramolecular rearrangement (isomerization). Temperatures (300-1100 degrees C), and the chemical environment (C(2)H(2)/H(2) molar ratios) were selected for relevancy to thermal treatment of PAH-contaminated soils under oxygen-free conditions. Molecular mechanics methods [MM3(92)] were used to compute thermochemical properties for calculation of equilibrium constants, i.e., heats of formation, standard entropies, and heat capacities for 30 PAH with empirical formulae C(14)H(10), C(16)H(10), C(18)H(10), C(18)H(12), C(20)H(10), and C(20)H(12). Included were 11 PAH containing only six-membered rings and 19 PAH containing both five- and six-membered rings. For each of these PAH the calculations predict that with increasing temperature, isomerization increases the "complexity" of the PAH mixture, i.e., the relative abundance of each PAH isomer in the mixture other than the most stable isomer, increases. Isomerization also partially transforms non-mutagens to mutagens, e.g., pyrene and benzo[e]pyrene to fluoranthene and benzo[a]pyrene, respectively, and partially converts cyclopenta[c, d]pyrene (CPEP) and chrysene, both human cell mutagens, to one and three additional human cell mutagens, respectively. Acetylene addition transforms the non-mutagens phenanthrene and pyrene to the mutagens triphenylene and CPEP, respectively. Some of the predicted PAH have been observed elsewhere among the products of aromatics pyrolysis. This study elucidates PAH reactivity for comparison with measurements, and identifies PAH reactions to be monitored and avoided in soil thermal decontamination and other waste remediation processes.

Dissecting a waiting list.

This study examines a list of 1,283 patients waiting for general and orthopaedic surgery in an outer London borough. In general surgery varicose vein and hernia surgery accounted for 60% of those waiting more than one year. Of those who had waited more than a year on the orthopaedic list 25% were waiting for knee replacement surgery. The average length of time spent waiting was 10 months, with some people waiting over 5 years. The impact of the numbers waiting a long time on aggregate waiting time was highlighted by weighting the numbers waiting by the months spent waiting. Analysis of urgency codes indicates that although there was a statistically significant relationship between urgency and the length of waiting time there were some anomalies. There was considerable inter-consultant variation in list size, waiting times and the case mix. Analysis of the flows onto the list and work done in one month showed that it would take a considerable time to clear some lists at present rates of activity. Disaggregated information such as this which explores the flows of patients on to and off of the lists is essential for the management of waiting lists and will become increasingly important as waiting lists become a feature of--'contracts'--service agreements, in the reformed NHS.