Construction of a fetal spatio-temporal cortical surface atlas from in utero MRI: Application of spectral surface matching

In this study, we construct a spatio-temporal surface atlas of the developing cerebral cortex, which is an important tool for analysing and understanding normal and abnormal cortical development. In utero Magnetic Resonance Imaging (MRI) of 80 healthy fetuses was performed, with a gestational age range of 21.7 to 38.9 weeks. Topologically correct cortical surface models were extracted from reconstructed 3D MRI volumes. Accurate correspondences were obtained by applying a joint spectral analysis to cortices for sets of subjects close to a specific age. Sulcal alignment was found to be accurate in comparison to spherical demons, a state of the art registration technique for aligning 2D cortical representations (average Fréchet distance≈0.4 mm at 30 weeks). We construct consistent, unbiased average cortical surface templates, for each week of gestation, from age-matched groups of surfaces by applying kernel regression in the spectral domain. These were found to accurately capture the average cortical shape of individuals within the cohort, suggesting a good alignment of cortical geometry. Each spectral embedding and its corresponding cortical surface template provide a dual reference space where cortical geometry is aligned and a vertex-wise morphometric analysis can be undertaken.

Total and unbound darunavir pharmacokinetics in pregnant women infected with HIV-1: results of a study of darunavir/ritonavir 600/100 mg administered twice daily

Objectives

Antiretroviral therapy during pregnancy is recommended to reduce the risk of mother-to-child transmission of HIV and for maternal care management. Physiological changes during pregnancy can affect pharmacokinetics, potentially altering pharmacological activity. We therefore evaluated the pharmacokinetics of twice-daily (bid) darunavir in HIV-1-infected pregnant women.

Methods

HIV-1-infected pregnant women receiving an antiretroviral regimen containing darunavir/ritonavir 600/100 mg bid were enrolled in this study. Total and unbound darunavir and total ritonavir plasma concentrations were obtained over 12 h during the second and third trimesters and postpartum. Total darunavir and ritonavir plasma concentrations were determined using a validated high-performance liquid chromatography tandem mass spectrometry assay and unbound darunavir was determined using ¹⁴C-darunavir-fortified plasma. Pharmacokinetic parameters were derived using noncompartmental analysis.

Results

Data were available for 14 women. The area under the plasma concentration–time curve from 0 to 12 h (AUC_12h) for total darunavir was 17–24% lower during pregnancy than postpartum. The AUC_12h for unbound darunavir was minimally reduced during pregnancy vs. postpartum. The minimum plasma concentration (C_min) of total and unbound darunavir was on average 43–86% and 10–14% higher, respectively, during pregnancy vs. postpartum. The antiviral response (< 50 HIV-1 RNA copies/mL) was 33% at baseline and increased to 73–90% during treatment; the percentage CD4 count increased over time. One serious adverse event was reported (increased transaminase). All 12 infants born to women remaining in the study at delivery were HIV-1-negative; four of these infants were premature.

Conclusions

Total darunavir exposure decreased during pregnancy. No clinically relevant change in unbound (active) darunavir occurred during pregnancy, suggesting that no dose adjustment is required for darunavir/ritonavir 600/100 mg bid in pregnant women.

Structural changes in freshwater fish and chironomids exposed to bacterial exotoxins

Mass fish mortalities have been reported in the past decade from British waters, often coinciding with blooms of filamentous actinobacteria, particularly strains of Streptomyces griseus. The present study has shown that some fractions of the exudate of S. griseus, prepared after a series of high pressure liquid chromatography (HPLC) separations, and analysed with liquid chromatography mass spectrometry (LC-MS), induced pathological changes to the gills of carp and/or tench fry following exposure under laboratory conditions up to 96 h Similar changes were induced by streptomycin, a secondary metabolite of S. griseus, and these included loss of microridging and fusion of secondary lamellae, with carp fry in the case of the exudate of S. griseus being more sensitive than tench fry, especially with exposure to fraction 9 and selected sub-fractions of 9. Some deformities using a severity index were also observed in the head capsule of larvae of the non-biting midge Chironomus riparius, including loss and splitting of teeth on the mentum. The results are discussed in relation to further identification of metabolites derived from samples of the organic filtrate of S. griseus and implications for the functioning of freshwater ecosystems.

Lipid and endothelium-related genes, ambient particulate matter, and heart rate variability--the VA Normative Aging Study

BACKGROUND

Many studies have shown that exposures to air pollution are associated with cardiovascular events, although the mechanism remains to be clarified. To identify whether exposures to ambient particles act on autonomic function via the lipid/endothelial metabolism pathway, whether effects of particulate matter <2.5 mum in aerodynamic diameter (PM(2.5)) on heart rate variability (HRV) were modified by gene polymorphisms related to those pathways were evaluated.

METHODS

HRV and gene data from the Normative Aging Study and PM(2.5) from a monitor located a kilometre from the examination site were used. A mixed model was fitted to investigate the associations between PM(2.5) and repeated measurements of HRV by gene polymorphisms of apolipoprotein E (APOE), lipoprotein lipase (LPL) and vascular endothelial growth factor (VEGF) adjusting for potential confounders chosen a priori.

RESULTS

A 10 microg/m(3) increase in PM(2.5) in the 2 days before the examination was associated with 3.8% (95% CI 0.2% to 7.4%), 7.8% (95 CI 0.4% to 15.3%) and 10.6% (95% CI 1.8% to 19.4%) decreases of the standard deviation of normal-to-normal intervals, the low frequency and the high frequency, respectively. Overall, carriers of wild-type APOE, LPL and VEGF genes had stronger effects of particles on HRV than those with hetero- or homozygous types. Variations of LPL-N291S, LPL-D9N and APOE-G113C significantly modified effects of PM(2.5) on HRV.

CONCLUSION

Associations between PM(2.5) and HRV were modified by gene polymorphisms of APOE, LPL and VEGF; the biological metabolism remains to be identified.

Mass mortality and its environmental and evolutionary consequences

The latest Mesozoic and earliest Tertiary sediments at Deep Sea Drilling Project site 524 provide an amplified record of environmental and biostratographic changes at the end of Cretaceous. Closely spaced samples, representing time intervals as short as 10(2) or 10(3) years, were analyzed for their bulk carbonate and trace-metal compositions, and for oxygen and carbon isotopic compositions. The data indicate that at the end of Cretaceous, when a high proportion of the ocean's planktic organisms were eliminated, an associated reduction in productivity led to a partial transfer of dissolved carbon dioxide from the oceans to the atmosphere. This resulted in a large increase of the atmospheric carbon dioxide during the next 50,000 years, which is believed to have caused a temperature rise revealed by the oxygen-isotope data. The lowermost Tertiary sediments at site 524 include fossils with Cretaceous affinities, which may include both reworked individuals and some forms that survived for a while after the catastrophe. Our data indicate that many of the Cretaceous pelagic organisms became extinct over a period of a few tens of thousands of years, and do not contradict the scenario of cometary impact as a cause of mass mortality in the oceans, as suggested by an iridium anomaly at the Cretaceous-Tertiary boundary.

Toxic effects of Streptomyces griseus spores and exudate on gill pathology of freshwater fish

Many unexplained fish-kills in British waters are considered microbial in origin and a large proportion of field sites contains elevated concentrations of filamentous actinobacteria. The present study has shown that a strain of Streptomyces griseus, isolated from field sites, elicits pathological changes to the gills of fish under laboratory conditions which mirror those found in situ. These changes include hyperplasia leading to fusion of the secondary lamellae and loss of microridging on the filamental epithelium of the primary lamellae. Juveniles of up to six fish species were exposed to spore suspensions or exudate of S. griseus in the range of 1 x 10(2)-1 x 10(6)spores ml(-1) for up to 96 h. The exudate was more potent than the spores and there was a positive correlation between exudate concentration and the rate and extent of fish gill pathology with bream and rainbow trout being more sensitive than carp, tench and roach. The results are discussed in the context of recognising and managing potential fish mortalities caused by microbial toxins.

HLA A and B locus antigens in patients with unexplained hepatitis following halothane anaesthesia

HLA A and B locus antigens were determined in 17 patients who had recovered from unexplained hepatitis following halothane anaesthesia. The greatest deviations from expected frequencies were observed with A1, A11 and BW22, but these differences were not statistically significant when the P values were corrected for the number of antigens tested. Although a larger series might show such deviations to be significantly different, HLA typing is of no predictive value in determining those at risk to hepatitis following repeated halothane exposure.

Suppression of HOX A cluster genes inhibits proliferation and induces cell death in human mixed-lineage leukemias

14020

Background: Leukemias harboring translocations of the mixed lineage leukemia locus (MLL) are generally associated with poor clinical prognosis. Using gene expression profiling we and others have previously shown that Homeobox (HOX) A cluster genes are highly expressed in leukemias with MLL rearrangements. Methods: Here we studied the role of aberrant HOXA9 expression in human MLL- rearranged and non-rearranged leukemias utilizing an shRNA mediated knockdown approach. Results: Three different shRNA constructs targeting human HOXA9 were synthesized and stably introduced into t(9;11) MOLM14 cells utilizing a lentiviral vector system. 75–80% HOXA9 RNA knockdown was confirmed by quantitative PCR and Western Blot analysis. In a panel of 17 AML/ALL cell lines (7 MLL rearranged, 10 non rearranged), HOXA9 directed shRNA inhibited cell proliferation starting as early as 48h after transduction, and induced apoptosis beginning at 72h. Interestingly, impaired cell proliferation and induction of apoptosis was significantly higher in the MLL rearranged cell lines (mean viability: 51.88%) than in the non-rearranged cells (mean viability: 90.98%; p=0.007) and also significantly correlated with the baseline HOXA9 mRNA expression before knockdown (R= 0.8, p=0.00017). We then further analyzed the effect of HOXA9 knockdown in MLL rearranged and non-rearranged primary human AML cells. Similar to our findings in cell lines, a marked induction of cell death was observed, which was significantly higher in leukemias with an MLL translocation (p=0.005) and also significantly correlated with the baseline HOXA9 mRNA expression (R= 0.8, p=0.001). Next, the in vivo effect of HOXA9 knockdown was assessed by transplanting luciferase-expressing SEMK2 (t4;11) cells into SCID-beige mice followed by in vivo bioluminescent imaging. Leukemia burden was significantly reduced in HOXA9 shRNA treated mice (n=10) with a peak difference at day 15 (p=0.000059) shortly before mice of the control group (n=10) succumbed from overt leukemia. At this point all mice of the HOXA9 shRNA treated group were still healthy with no signs of leukemia. Conclusions: Taken together our data implicates that depletion of HOXA9 might be a novel approach for targeted therapy in human MLL rearranged leukemias.

No significant financial relationships to disclose.

Lisfranc injury in a national hockey league player: a case report

Tarsometatarsal joint dislocations and fracture-dislocations are uncommon injuries most frequently resulting from high-energy trauma as encountered in crush injuries, falls, and motor vehicle accidents. Although less common in athletes, this injury is being recognized with greater frequency and may carry a poor prognosis for return to high levels of competition. These injuries present a considerable challenge to orthopedic surgeons caring for athletes because of the prolonged period of recovery often required [ 1,2,5,6,12]. The literature contains descriptions of this injury in football players, gymnasts, tennis players, and track and field athletes [2,5,9]. To our knowledge, no report of such a Lisfranc injury to a hockey player has been described. This is a case report of a National Hockey League player that sustained a Lisfranc injury requiring surgical stabilization, but was able to return to elite hockey play.

Studies on Media for Enumerating Enterococci in Frozen Vegetables

A study was made of the relative sensitivity and specificity of presumptive and confirmatory media for the most probable number enumeration of enterococci in frozen vegetables. Azide dextrose broth yielded the highest numbers of confirmable enterococci and its sensitivity was shown to be comparable to nonselective media. The use of ethyl violet azide broth as a confirmatory medium resulted in a significant number of false positive tests. Growth in broth containing 6.5% sodium chloride incubated at 45 C for 2 days was found to be a more specific confirmatory test for enterococci.