Age-specific prevalence and causes of blindness and visual impairment in an older population: the Rotterdam Study

OBJECTIVE: To study the prevalence and causes of blindness and visual impairment in various age categories of a large population-based study. METHODS: For the study, 6775 subjects aged 55 years or older underwent an extensive ophthalmologic screening examination, including measurements of visual acuity and the visual field and fundus photography. The causes of blindness or visual impairment were determined using all screening information and medical records. RESULTS: The prevalence of blindness, according to World Health Organization criteria, ranged from 0.1% in subjects aged 55 to 64 years to 3.9% in subjects aged 85 years or older; the prevalence of visual impairment ranged from 0.1% to 11.8%. For persons younger than 75 years, myopic degeneration and optic neuropathy were the most important causes of impaired vision. For persons aged 75 years or older, age-related macular degeneration was the major cause of the increased prevalence of blindness, whereas age-related cataract predominantly caused the increased prevalence of visual impairment. CONCLUSIONS: The hierarchy of causes of blindness and visual impairment is highly determined by age. As yet, little can be done to reduce the exponential increase of blindness; however, adequate implementation of surgery to treat cataract could reduce visual impairment by one third. Underuse of ophthalmologic care is a prominent cause of the high frequency of untreated cataracts among the elderly.     

Mast cell infiltration in acute coronary syndromes: implications for plaque rupture

The time-course of uterine growth, cell proliferation, and microvascular development was evaluated during the first 72 h after implanting estradiol-17beta (E2) into ovariectomized (OVX) ewes. Uterine fresh weight increased 2.3-fold by 24 h and increased further (3.3-fold) by 48 h. The majority (approximately 75%) of this growth response was associated with tissue growth rather than a change in the tissue dry weight:fresh weight ratio. Both uterine cell number (DNA content) and cell size (RNA:DNA ratio) increased from 0 to 24 h (1.8-fold and 1.7-fold, respectively). Cell proliferation also increased dramatically between 8 h and 24 h after E2 implantation. Endometrial microvascular volume density (percentage of tissue volume occupied by microvessels) increased approximately 1.8-fold by 24 h and then remained constant or declined slightly through 72 h. The total endometrial microvascular volume, however, increased approximately 5-fold from 0 to 24 h and increased further by 72 h. Thus, treatment of OVX ewes with E2 caused a dramatic increase in uterine fresh and dry weights by 24 h, due primarily to hyperplasia and hypertrophy, with only a relatively small change in tissue dry weight:fresh weight ratio. This dramatic uterine growth was associated with a profound increase in endometrial microvascular volume.     

Three-dimensional CT angiography of the thorax: clinical applications

Spiral CT with three-dimensional (3D) display can provide a rapid noninvasive examination of the vascular system and has been shown to have a wide range of clinical applications in the thorax, including imaging of the aorta, pulmonary vasculature, and venous abnormalities. Three-dimensional images can provide views of the imaging volume from innumerable viewing angles for both the radiologist and referring clinician, and potentially obviate invasive procedures such as angiography. In this article, we will review many of these applications of spiral CT angiography with 3D displays. Emphasis is placed on study design, protocol selection, and display of pathology.     

Impact of a clinical pathway for elective infrarenal aortic reconstructions

OBJECTIVE: To determine the impact of a clinical pathway for elective infrarenal aortic reconstruction on outcome, resource utilization, and cost in a university medical center. SUMMARY BACKGROUND DATA: Clinical pathways have been reported to control costs, reduce resource utilization, and maintain or improve the quality of patient care, although their use during elective aortic reconstructions remains unresolved. METHODS: A clinical pathway was developed for elective infrarenal aortic reconstructions by a multidisciplinary group comprised of representatives from each involved service. The prepathway practice and costs were analyzed and an efficient, cost-effective practice with specific outcome measures was defined. The impact of the pathway was determined by retrospective comparison of outcome, resource utilization, and cost (total and direct variable) between the pathway patients (PATH, n = 45) and a prepathway control group (PRE, n = 20). RESULTS: There were no significant differences in the patient demographics, comorbid conditions, operative indications, or type of reconstruction between the groups. There were no operative deaths and the overall complication rate (PRE, 35% vs. PATH, 34%) was similar. The pathway resulted in significant decreases in the total length of stay and preoperative length of stay and a trend toward a significant decrease (p = 0.08) in the intensive care length of stay for the admission during which the operation was performed. The pathway also resulted in significant decreases in both direct variable and total hospital costs for this admission, as well as a significant decrease in the overall direct variable and total hospital costs for the operative admission and the preoperative evaluation (< or =30 days before operative admission). Despite these reductions, the discharge disposition, 30-day readmissions, and number of postoperative clinic visits within 90 days of discharge were not different. CONCLUSIONS: Implementation of a clinical pathway for elective infrarenal aortic reconstructions dramatically decreased resource utilization and hospital costs without affecting the quality of patient care and did not appear to shift the costs to another setting.     

In vivo delayed-type hypersensitivity skin test anergy in human immunodeficiency virus type 1 infection is associated with T cell nonresponsiveness in vitro

In a cross-sectional study, the prevalence of delayed-type hypersensitivity skin test anergy (DTHA) was examined in 136 asymptomatic human immunodeficiency virus-infected participants in relation to immunologic and virologic parameters. DTHA was assessed with a multitest cell-mediated immunity skin test. Of the 136 participants, with a mean CD4 T cell count of 335 x 10(6)/L, 25 were anergic (18.4%). In the stepwise forward multivariate logistic regression models, after adjustment for CD4 T cell counts, depending on whether it was analyzed continuously or after dichotomization (20th percentile), both T cell reactivity to CD2 plus CD28 antibodies or to CD3 antibodies were the most predictive markers of DTHA (odds ratio, 0.80; 95% confidence interval, 0.67-0.94; and odds ratio, 2.97; 95% confidence interval, 1.1-8.3, respectively). This study shows a strong correlation between the decreased T cell responses in vitro and DTHA. Therefore, next to DTHA testing, T cell function assays may be useful to test immune reconstitution observed during antiretroviral treatment.     

Remodeling of HDL by phospholipid transfer protein: demonstration of particle fusion by 1H NMR spectroscopy

There is evidence that phospholipid transfer protein (PLTP) can increase reverse cholesterol transport by inducing favorable subclass distribution in the high density lipoprotein (HDL) fraction. This includes generation of initial cholesterol acceptor particles, pre beta-HDL, and of enlarged particles that are rapidly cleared from the circulation. However, partly because of methodological difficulties, the mechanisms behind the PLTP-mediated interconversion of HDL particles are not fully understood. In this communication, we describe the use of a novel methodology, based on 1H NMR spectroscopy, to study the PLTP-induced size changes in the HDL particles. In accordance with native gradient gel electrophoresis, the 1H NMR data revealed a gradual production of enlarged HDL particles in the HDL3+ PLTP mixtures. In addition, according to a physical model for lipoprotein particles, relating the frequency shifts observable with NMR to the size of the lipoprotein particles, the NMR data demonstrated that PLTP-mediated HDL remodeling involves fusion of the HDL particles.     

Preventable trauma deaths in Singapore

The international normalized ratio (INR) is the current standard for monitoring anticoagulation therapy. Although simple to determine, it normally requires venipuncture and extensive laboratory resources for specimen handling and analysis. The portable capillary whole blood coagulation monitor is an alternative to laboratory venipuncture. Its promoted advantages are: it obtains a blood sample by finger-stick versus venipuncture; rapid turnaround time for results; resultant dosage adjustments (as appropriate) performed in minutes versus hours or days after testing; relative ease of use by nonlaboratory personnel; and potential for home monitoring. This project compared the results of INRs obtained through the venipuncture/laboratory process to INRs obtained by the portable monitoring process at the National Naval Medical Center. A correlation coefficient of 0.97 was determined. The difference in the mean INR results of the two testing methods was not clinically significant (p = 0.269). The portable monitor was determined to be a viable alternative to laboratory testing.     

Cleavage and activation of p21-activated protein kinase gamma-PAK by CPP32 (caspase 3). Effects of autophosphorylation on activity

p21-activated protein kinase gamma-PAK (Pak2, PAK I) is cleaved by CPP32 (caspase 3) during apoptosis and plays a key role in regulation of cell death. In vitro, CPP32 cleaves recombinant gamma-PAK into two peptides; 1-212 contains the majority of the regulatory domain whereas 213-524 contains 34 amino acids of the regulatory domain plus the entire catalytic domain. Following cleavage, both peptides become autophosphorylated with [gamma-32P]ATP. Peptide 1-212 migrates at 27,000 daltons (p27) upon SDS-polyacrylamide gel electrophoresis and at 32,000 daltons following autophosphorylation on serine (p27P); the catalytic subunit migrates at 34,000 daltons (p34) before and after autophosphorylation on threonine. Following caspase cleavage, a significant lag (approximately 5 min) is observed before autophosphorylation and activity are detected. When gamma-PAK is autophosphorylated with ATP(Mg) alone and then cleaved, only p27 contains phosphate, and the enzyme is inactive with exogenous substrate. After autophosphorylation of gamma-PAK in the presence of Cdc42(GTPgammaS) or histone 4, both cleavage products contain phosphate and gamma-PAK is catalytically active. Mutation of the conserved Thr-402 to alanine greatly reduces autophosphorylation and protein kinase activity following cleavage. Thus activation of gamma-PAK via cleavage by CPP32 is a two-step mechanism wherein autophosphorylation of the regulatory domain is a priming step, and activation coincides with autophosphorylation of the catalytic domain.