Length of Life: A Ten Year Retrospective Study of 209 Clients Who Died in Minnesota's State Facilities for Persons with Developmental Disabilities in the 1980s

A retrospective study was conducted to determine characteristics associated with different lifespans for Minnesota's institutionalized clients with developmental disabilities. The individual client records of 209 persons who died between January 1, 1980 and December 31, 1989 were reviewed. The data revealed that clients with cerebral palsy and seizure disorders lived significantly shorter lives than those clients who did not have these disabilities. Clients with severe/profound mental retardation lived significantly shorter lives than those clients diagnosed with moderate/mild retardation. Gender differences in mean lengths of life were also significant: females lived significantly longer than males. Significant differences were not found between clients with sensory impairments and those without sensory deficits. In general, the younger the clients' ages at admission to the state facilities, the shorter the individuals' lifespan. These data are compared to previous findings on life expectancy.     

Quantitative stereological evaluation of KCl-induced ultrastructural changes in frog brain

Quantitative stereological techniques were applied to electron micrographs obtained from frog brain that was stimulated with KCI and then subjected to rapid freeze fixation. Morphometric measurements demonstrated that: (1) no changes occurred in presynaptic structures; (2) the postsynaptic elements (dendritic shafts and dendritic spines) which occupied only 4.8% of the tissue volume in the control experiments, increased in volume to 14.2% of the stimulated tissue without any change in surface area of their boundary membranes; (3) the extracellular space decreased from 19,6% of the tissue volume in the control preparations to 6.7% in the stimulated.A method was developed for correcting the morphometric underestimation of the extracellular space resulting from the partial obscuring of these narrow regions between cells by obliquely cut plasma membranes in sections of finite thickness. The mean width of extracellular spaces was shown to be reduced from 44.3 nm to 18.0 nm after KC1 stimulation.These measurements imply that when stimulated with KC1 the extracellular space of the frog cortex is taken up by the dendritic structures which swell up and change their shape—increasing their volume without a change in their membrane surface area. The role of these changes with respect to the altering synaptic potency and providing a mechanism for neuronal plasticity is discussed.     

Considerations for Implementing Group‐Level Prenatal Health Interventions in Low‐Resource Communities: Lessons Learned From Haiti

Haiti's high maternal and infant mortality rates evidence an urgent need for implementation of evidence‐based strategies. A potential cost‐effective strategy to mitigate high maternal and infant mortality rates is group prenatal care, an innovative model that combines antenatal clinical assessment with pregnancy education. Despite research demonstrating the effectiveness of this model in high‐resource settings, less is known about the challenges of implementing it in low‐resource settings. The purpose of this article is to provide recommendations for overcoming challenges of implementing group prenatal care in low‐resources communities globally. Challenges addressed include language, literacy, space, cultural appropriateness of intervention content, and sociopolitical climate. Using examples from work conducted in Haiti, this information can be used to assist practitioners and researchers with overcoming challenges of implementing models of group care in international low‐resource communities.     

New possibilities for volumetric-modulated arc therapy using the AgilityTM 160-leaf multileaf collimator

Purpose

This study compares the quality of intensity-modulated radiotherapy (IMRT) and volumetric-modulated arc therapy (VMAT) plans optimized for an Elekta Agility^TM (Elekta, Stockholm, Sweden) multileaf collimator (MLC; leaf width 5 mm) and an Elekta MLCi2 (leaf width 10 mm) for complex target volumes (anal, AC; head and neck, H&N and prostate cancer, PC).

Patients and methods

For plan comparisons, 15 patients who had been treated with IMRT or VMAT using the MLCi2 were selected. For each patient, a retrospective treatment plan using the MLCi2 for the technique not applied was created, as were treatment plans for both techniques using the Agility^TM MLC. Dose–volume histograms (DHVs) for planning target volumes (PTVs) and organs at risk (OARs) were compared. Further parameters relating to dose conformity, dose homogeneity and mean dose (D_mean) to the PTV, compliance with the intended OAR dose criteria and overall dose to normal tissue were analyzed. Verification measurements were performed and optimization and treatment times were compared.

Results

Compared to the MLCi2 plans, the Agility^TM IMRT and VMAT plans show better or equivalent results in terms of PTV dose conformity and homogeneity. Compliance with the intended OAR dose criteria does not differ according to technique or MLC type. Slight differences are shown for dose distributions in OARs and normal tissue. Verification measurements show that all plans fulfill the acceptance criteria of a minimum of 95 % matched dose points for the 3 %/3 mm γ criterion. Optimization times for the VMAT plans increase compared to the IMRT plans, whereas treatment times decrease.

Conclusion

With the MLCi2, treatment of complex target volumes with VMAT was only possible with compromises in terms of target coverage. Using the Agility^TM MLC, even complex target volumes can be treated with VMAT without compromising target coverage or resulting in higher exposure of OARs or normal tissue.