Association between second-trimester cervical length and cesarean delivery in multiparas.

OBJECTIVES: The purpose of this study was to determine whether there is an association between second-trimester cervical length and cesarean delivery in women with a prior vaginal delivery. METHODS: We conducted a retrospective cohort study of multiparous women with singleton gestations who underwent routine cervical length screening between 18 and 24 weeks' gestation and labored after 34 weeks. Cervical lengths were divided into quartiles, and the frequency of cesarean delivery was compared across the groups. Indications for cesarean delivery were also compared. A multivariable logistic regression was performed with cervical length as a categorical and a continuous variable to adjust for potential confounders. RESULTS: Of the 2260 multiparas who met inclusion criteria, 63 (2.8%) underwent a cesarean delivery. We observed no association between the second-trimester cervical length quartile and the frequency of cesarean delivery (2.1%, 3.5%, 2.3%, and 3.1%, respectively; P = .434). Further analysis using cervical length as a continuous variable and controlling for potential confounding variables did not change this result (adjusted odds ratio, 1.08; 95% confidence interval, 0.80-1.46). CONCLUSIONS: The second-trimester cervical length quartile in multiparas is not associated with an increased frequency of cesarean delivery. This finding differs from studies of nulliparas.

Isolation of entomopathogenic fungi from soils and Ixodes scapularis (Acari: Ixodidae) ticks: prevalence and methods.

Entomopathogenic fungi are commonly found in forested soils that provide tick habitat, and many species are pathogenic to Ixodes scapularis Say, the blacklegged tick. As a first step to developing effective biocontrol strategies, the objective of this study was to determine the best methods to isolate entomopathogenic fungal species from field-collected samples of soils and ticks from an Eastern deciduous forest where I. scapularis is common. Several methods were assessed: (1) soils, leaf litter, and ticks were plated on two types of media; (2) soils were assayed for entomopathogenic fungi using the Galleria bait method; (3) DNA from internal transcribed spacer (ITS) regions of the nuclear ribosomal repeat was extracted from pure cultures obtained from soils, Galleria, and ticks and was amplified and sequenced; and (4) DNA was extracted directly from ticks, amplified, and sequenced. We conclude that (1) ticks encounter potentially entomopathogenic fungi more often in soil than in leaf litter, (2) many species of potentially entomopathogenic fungi found in the soil can readily be cultured, (3) the Galleria bait method is a sufficiently efficient method for isolation of these fungi from soils, and (4) although DNA extraction from ticks was not possible in this study because of small sample size, DNA extraction from fungi isolated from soils and from ticks was successful and provided clean sequences in 100 and 73% of samples, respectively. A combination of the above methods is clearly necessary for optimal characterization of entomopathogenic fungi associated with ticks in the environment.

Clinical and pathological effects of intrathecal injection of mesenchymal stem cell-derived neural progenitors in an experimental model of multiple sclerosis.

Multiple sclerosis (MS) is associated with irreversible disability in a significant proportion of patients. At present, there is no treatment to halt or reverse the progression of established disability. In an effort to develop cell therapy-based strategies for progressive MS, we investigated the pre-clinical efficacy of bone marrow mesenchymal stem cell-derived neural progenitors (MSC-NPs) as an autologous source of stem cells. MSC-NPs consist of a subpopulation of bone marrow MSCs with neural progenitor and immunoregulatory properties, and a reduced capacity for mesodermal differentiation, suggesting that this cell population may be appropriate for clinical application in the CNS. We investigated whether MSC-NPs could promote repair and recovery after intrathecal injection into mice with EAE. Multiple injections of MSC-NPs starting at the onset of the chronic phase of disease improved neurological function compared to controls, whereas a single injection had no effect on disease scores. Intrathecal injection of MSC-NPs correlated with reduced immune cell infiltration, reduced area of demyelination, and increased number of endogenous nestin-positive progenitor cells in EAE mice. These observations suggest that MSC-NPs may influence the rate of repair through effects on endogenous progenitors in the spinal cord. This study supports the use of autologous MSC-NPs in MS patients as a means of promoting CNS repair.

Binding mode and affinity studies of DNA-binding agents using topoisomerase I DNA unwinding assay.

A topoisomerase I DNA unwinding assay has been used to determine the relative DNA-binding affinities of a model pair of homologous naphthalene diimides. Binding affinity data were corroborated using calorimetric (ITC) and spectrophotometric (titration and T(m)) studies, with substituent size playing a significant role in binding. The assay was also used to investigate the mode of binding adopted by several known DNA-binding agents, including SYBR Green and PicoGreen. Some of the compounds exhibited unexpected binding modes.

Synthesis of analogues of a flexible thiopyrylium photosensitizer for purging blood-borne pathogens and binding mode and affinity studies of their complexes with DNA.

A series of thio- and selenopyrylium analogues of 2,4-di(4-dimethylaminophen-yl)-6-methylthiopyrylium iodide were prepared in five steps from 4-dimethylaminophenyl-propargyl aldehyde and the corresponding lithium acetylide. When bound to DNA, all of the dyes absorb at wavelengths >600nm, which avoids the hemoglobin band I maximum at 575nm. The binding of the series of dyes to double-stranded DNA was examined spectrophotometrically and by isothermal titration calorimetry to determine binding constants, by a topoisomerase I DNA unwinding assay, by competition dialysis with [poly(dGdC)](2) and [poly(dAdT)](2), and by ethidium bromide displacement studies to examine propensities for intercalation, and by circular dichroism studies. The dyes were found to show mixed binding modes.