The use of visual information for planning accurate steps in a cluttered environment

When an observer walks across irregular terrain, he uses vision to plan his steps. How far in advance of each step does he acquire the critical information? We trained cats to walk accurately down a cluttered alley, and then turned out the light in mid-trial. Cats usually continued to walk without error for one to four steps, indicating that they had acquired the information to guide each step well before foot contact.     

Age and sex differences in tibia morphology in healthy adult Caucasians

Variability in peripheral Quantitative Computed Tomography (pQCT) measurement sites limits direct comparisons of results between studies. Further, it is unclear what estimates of bone strength are most indicative of changes due to aging, disease, or interventions. The purpose of this study was to examine age group and sex differences in tibia morphology. Additional purposes of this study were to determine which tibia site or sites are most sensitive for detecting age and sex differences.MethodsSelf-identifying Caucasian men (n = 55) and women (n = 59) ages 20–59 years and separated by decades had their non-dominant tibias measured with pQCT (Stratec XCT 3000) at every 10% of the limb length from 5% to 85% (distal to proximal). Volumetric BMD and BMC of the total, cortical and trabecular bone were determined, as well as periosteal (PeriC) and endosteal (EndoC) circumferences, and cortical thickness (CTh).ResultsThere were significant (p < 0.01) site effects for all BMC, vBMD, PeriC and EndoC measures. Large sex differences (men > women) in Tot.BMC (21–28%) were paralleled by differences in Cort.BMC (21–25%) (p < 0.01). Site 1 sex interaction effects were significant (p < 0.05) for BMC (peak sex difference: 5%, 15%, 25%, 85% sites) and circumference (peak sex difference: 65% site) variables. CTh and total vBMD were lowest (p < 0.05) in 50–59 year group, and EndoC was highest in the 50–59 year group. Site 1 age interactions existed for Cort.vBMD, Tot.BMC (85% site), and EndoC (25%, 35%, 55%–85% sites). Correcting for bone free lean body mass (BFLBM) greatly reduced sex differences, eliminating sex 1 site interaction effects, but sex main effects remained significant. Correcting for BFLBM did not eliminate age effects.ConclusionThe magnitude of age and sex differences in tibia variables varied by measurement site demonstrating the need for standardization of measurement sites.     

Complement activation in stored platelet concentrates

Activation of platelets during preparation and/or storage of platelet concentrates in plastic containers at room temperature has recently been recognized. Many different biologic causes of this activation have been postulated. Activated complement, as a multi-enzyme system, is one of the possible sources of molecules leading to platelet activation. To detect complement activation, functional complement activity and the generation of complement-derived ligands were investigated in platelet concentrate supernatant plasma during 5 days of storage at room temperature. Hemolytic tests for functional classical and alternative pathway activity were used, as was the kinetic test for complement- mediated inhibition of immune complex precipitation. The presence of C3 activation products (C3, C3c, C3dg) was investigated in plasma by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and Western blotting procedures and on platelets by immunofluorescence. Activation of complement was evident during storage, and C3c and C3d fragments were clearly demonstrated in plasma. The amount of C3d fragments on platelets gradually rose during the first 3 days of storage. At the end of 5 days of storage, the platelets became C3d negative. There are two possible mechanisms of C3d disappearance–shedding and/or further degradation of C3d fragments. Those results indicated that complement activation and the generation of complement-dependent ligand-receptor interaction may be mechanisms for platelet activation in concentrates stored at room temperature.     

New and underutilised technologies to reduce maternal mortality and morbidity: what progress have we made since Bellagio 2003?

In 2003, maternal health experts met in Bellagio, to consider new and underutilised technologies vital to pregnancy-related health services in low-resource settings. Five years later, we examine what progress has been made and what new opportunities may be on the horizon. Based on a review of literature and consultation with experts, we consider technologies addressing the five leading causes of maternal mortality: postpartum haemorrhage, eclampsia, obstructed labour, puerperal sepsis, and unsafe abortion (pregnancy termination and miscarriage). In addition, we consider technologies related to obstetric fistula, which has received more attention in recent years.     

Secondary glaucoma after intravitreal dexamethasone implant (Ozurdex) injection in patients with retinal disorder: A retrospective study

Purpose:To investigate the rate of secondary glaucoma after intravitreal (IV) dexamethasone implant (ozurdex) 0.7 mg injection in a retinal disorder over a clinical treatment period of 2 years in a tertiary eye care center.Methods:Retrospective study based on the records of patients receiving IV ozurdex 0.7 mg implant for T/t of cystoid macular edema (CME), diabetic macular edema (DME), macular edema due to central retinal vein occlusion/branch retinal vein occlusion (CRVO/BRVO), and choroidal neovascular membrane (CNVM) at a tertiary eye care hospital for 2 years with 6 months of follow-up. The post-T/t intraocular pressure (IOP) and antiglaucoma medication (AGM) required was recorded at day 1, 1 week, 1, 2, 3, 4, and 6 months and analyzed for secondary IOP spike or ocular hypertension defined as IOP >21 mmHg at any point in time. The patients with pre-existing glaucoma and lost to follow-up were excluded.Results:A total of 102 eyes of 80 patients were included in the study. The mean baseline IOP was 14.40 + 2.97 mmHg, post-injection was 15.01 + 3.22 mmHg at day 1, 15.15 + 3.28 mmHg at 1 week, 15.96 + 3.62 mmHg at 1 month, 16.26 + 3.95 mmHg at 2 months, 15.41 + 3.33 mmHg at 3 months, 15.38 + 3.28 mmHg at 4 months, and 14.27 + 2.69 mmHg at 6 months. No significant difference was seen from baseline IOP at day 1 (P = 0.163), 1 week (P = 0.086), and 6 months (P = 0.748). Statistically significant difference was seen at 1 month (P = 0.0009), 2 months (P = 0.0001), 3 months (P = 0.023), and 4 months (P = 0.026). The mean IOP peak at 2 months recovered to baseline by 6 months subgroup IOP trend shows a similar variation and the results are consistent with the studies in the literature. About 19/102 (18.62%) eyes showed an IOP spike post-T/t. The maximum was seen at 2 months; 16 eyes showed a rise in the range 22–25 mmHg; 8 in the range 26–30 mmHg; and 1 eye had 34 mmHg and required multiple AGM—no surgical intervention was needed.Conclusion:A secondary IOP spike post-IV ozurdex 0.7 mg seen in 18.62% of the cases require AGM. The IOP monitoring should be meticulously performed for the variations and secondary IOP spike management to prevent irreversible damage to the optic nerve and visual field.     

Non‐medically supervised treatment interruptions among participants in a universally accessible antiretroviral therapy programme

Background

We examined clinical outcomes, patient characteristics and trends over time of non‐medically supervised treatment interruptions (TIs) from a free‐of‐charge antiretroviral therapy (ART) programme in British Columbia (BC), Canada.

Methods

Data from ART‐naïve individuals ≥18 years old who initiated triple combination highly active antiretroviral therapy (HAART) between January 2000 and June 2006 were analysed. Participants having ≥3 month gap in HAART coverage were defined as having a TI. Cox proportional hazards modelling was used to examine factors associated with TIs and to examine factors associated with resumption of treatment.

Results

A total of 1707 participants were study eligible and 643 (37.7%) experienced TIs. TIs within 1 year of ART initiation decreased from 29% of individuals in 2000 to 19% in 2006 (P<0.001). TIs were independently associated with a history of injection drug use (IDU) (P=0.02), higher baseline CD4 cell counts (P<0.001), hepatitis C co‐infection (P<0.001) and the use of nelfinavir (NFV) (P=0.04) or zidovudine (ZDV)/lamivudine (3TC) (P=0.009) in the primary HAART regimen. Male gender (P<0.001), older age (P<0.001), AIDS at baseline (P=0.008) and having a physician who had prescribed HAART to fewer patients (P=0.03) were protective against TIs. Four hundred and eighty‐eight (71.9%) participants eventually restarted ART with male patients and those who developed an AIDS‐defining illness prior to their TI more likely to restart therapy. Higher CD4 cell counts at the time of TI and unknown hepatitis C status were associated with a reduced likelihood of restarting ART.

Conclusion

Treatment interruptions were associated with younger, less ill, female and IDU participants. Most participants with interruptions eventually restarted therapy. Interruptions occurred less frequently in recent years.

     

An experience of virtual leadership development for human resource managers

Problem  

Strong leadership and management skills are crucial to finding solutions to the human resource crisis in health. Health professionals and human resource (HR) managers worldwide who are in charge of addressing HR challenges in health systems often lack formal education in leadership and management.