A locus for autosomal dominant anterior polar cataract on chromosome 17p

Inherited cataract is a clinically and genetically heterogeneous disease. Here we report the identification of a new locus for an autosomal dominant anterior polar cataract on the short arm of chromosome 17. To map this new locus we performed genetic linkage analysis with microsatellite markers in a four-generation pedigree. After exclusion of seven candidate loci for cataract, we obtained significant positive LOD scores for markers D17S849 (Z = 4.01 / theta = 0.05) and D17S796 (Z = 4.17 / theta = 0.05). Multipoint analysis gave a maximum LOD score of 5.2 (theta max = 0.06) between these two markers. From haplotype analysis, the cataract locus lies in the 13 cM interval between markers D17S849 and D17S796. This study provides the first genetic mapping of an autosomal dominant anterior polar cataract.      

Examination of the Short-Term Efficacy of a Parent-Based Intervention to Prevent Skin Cancer

The research evaluated an intervention strategy designed to prevent skin cancer in young adolescents. The intervention used parents as change agents to effectively communicate the risks of skin cancer and encourage their children to avoid high-risk sun-related behaviors while increasing positive sun-safe behaviors. Three hundred and forty parents in two regions of the United States were educated about the dangers of risky sun behaviors and how to convey information about skin cancer prevention to their children. Parents were then encouraged to talk with their children about these issues over a 1-month period prior to the onset of summer. Following this time period, children whose parents received and implemented the intervention materials were compared with a control sample of 129 children. These two groups were matched on age, gender, and school on number of sunburns and sunburn severity, attitudes and beliefs, and sunbathing behavior. Children in the treatment condition differed significantly from controls in the predicted directions on all outcome variables. The findings are discussed in terms of reducing skin cancer risk behaviors of children via parent-based intervention approaches.     

Fluid and solid mechanical implications of vascular stenting

Vascular stents have emerged as an effective treatment for occlusive vascular disease. Despite their success and widespread use, outcomes for patients receiving stents are still hampered by thrombosis and restensosis. As arteries attempt to adapt to the mechanical changes created by stents, they may in fact create a new flow-limiting situation similar to that which they were intended to correct. In vitro fluid mechanics and solid mechanics studies of stented vessels have revealed important information about how stents alter the mechanical environment in the arteries into which they are placed. Adverse nonlaminar flow patterns have been demonstrated as well as remarkably high stress concentrations in the vessel wall. In vivo studies of stented vessels have also shown a strong relationship between stent design and their dynamic performance within arteries. Alterations in pressure and flow pulses distal to the stent have been observed, as well as regional changes in vascular compliance. Considering the influence of flow and stress on the vascular response and the suboptimal clinical outcomes associated with stenting, knowledge gained from stent/artery mechanics studies should play an increasingly important role in improving the long-term patency of these devices. © 2002 Biomedical Engineering Society. PAC2002: 8719Rr, 8780-y, 8719Uv     

Characterization of liposome suspensions by flow cytometry

Novel approaches to drug delivery and induction of immune responses using liposomes have received much attention in recent years. Liposomes, however, are not a singular entity, but can be produced with a diverse group of phospholipids that form microspheres of different sizes, physical structure, electrochemical characteristics, and most importantly, physiologic properties. The purpose of this study was to establish the usefulness of flow cytometry as a convenient, rapid method for assessing the relative size and uniformity of liposomal preparations. Liposomes were made from phospholipid suspensions by sonication alone, or sonication followed by microemulsification. Forward laser light scatter (FSC) analysis of liposomal preparations by flow cytometry indicated that microemulsification produced homogeneous, small vesicles which were less than 1 micron in diameter, compared to the more heterogeneous sized liposomes generated by sonication alone. Transmission electron micrographs of the liposomal preparations were used to confirm the FSC results and showed that liposomes prepared by microemulsification were homogeneous, unilamellar vesicles which exhibited a mean diameter of 99.8 nm, whereas the sonicated-only preparation was more heterogeneous in size, exhibiting a mean diameter of 154.1 nm. Analysis of various liposome preparations by FSC during a 9 week storage period showed that small vesicles were relatively stable. We conclude that flow cytometry using FSC analysis provides a rapid, reproducible and convenient method to evaluate the relative size, uniformity and stability of liposomes.     

Pretreatment with corticosteroids to alleviate reactions to intravenous contrast material

The x-ray contrast mediums used over the past three decades have been salts of iodinated acids administered in highly hypertonic concentrations. We conducted a multiinstitutional randomized study of the protective effects of pretreatment with corticosteroids against reactions to intravenous contrast material. We gave 6763 patients two doses of oral corticosteroids (methylprednisolone, 32 mg) approximately 12 hours and 2 hours before challenge with contrast material, one dose of oral prednisolone approximately 2 hours before challenge, or placebo in the same dosages. The two-dose corticosteroid regimen, but not the one-dose regimen, significantly reduced the incidence of reactions of all types (P less than 0.05) except a category of reactions dominated by hives, for which the reduction approached significance (P = 0.055). In recent years, several relatively expensive monomeric nonionic iodinated compounds having approximately half the osmolality of the corresponding ionic compounds and a lower reaction rate have become available. With our two-dose corticosteroid regimen, the incidence of reactions necessitating therapy in patients receiving the ionic medium approximated that reported in an unblinded nonrandomized study of patients receiving a newer intravenous nonionic medium without corticosteroid pretreatment. We conclude that the much less expensive ionic medium, if administered with corticosteroid pretreatment, may serve as a reasonable alternative to intravenous nonionic medium, without loss of safety.     

Case records of the Massachusetts General Hospital. Weekly clinicopathological exercises. Case 28-2001. A 44-year-old woman with chills, fever, jaundice, and hepatic abscesses

BACKGROUND: The introduction of expensive but very effective antiviral medications has led to questions about the effects on the total use of resources for the care of patients with human immunodeficiency virus (HIV) infection. We examined expenditures for the care of HIV-infected patients since the introduction of highly active antiretroviral therapy. METHODS: We interviewed a random sample of 2864 patients who were representative of all American adults receiving care for HIV infection in early 1996, and followed them for up to 36 months. We estimated the average expenditure per patient per month on the basis of self-reported information about care received. RESULTS: The mean expenditure was $1,792 per patient per month at base line, but it declined to $1,359 for survivors in 1997, since the increases in pharmaceutical expenditures were smaller than the reductions in hospital costs. Use of highly active antiretroviral therapy was independently associated with a reduction in expenditures. After adjustments for the interview date, clinical status, and deaths, the estimated annual expenditure declined from $20,300 per patient in 1996 to $18,300 in 1998. Expenditures among subgroups of patients varied by a factor of as much as three. Pharmaceutical costs were lowest and hospital costs highest among underserved groups, including blacks, women, and patients without private insurance. CONCLUSIONS: The total cost of care for adults with HIV infection has declined since the introduction of highly active antiretroviral therapy. Expenditures have increased for medications but have declined for other services. However, there are large variations in expenditures across subgroups of patients.