Nonmelanoma skin cancer in relation to ionizing radiation exposure among U.S. radiologic technologists

Ionizing radiation (IR) is an established cause of nonmelanoma skin cancer, but there is uncertainty about the risk associated with chronic occupational exposure to IR and how it is influenced by ultraviolet radiation (UVR) exposure. We studied 1,355 incident cases with basal cell carcinoma (BCC) and 270 with squamous cell carcinoma (SCC) of the skin in a cohort of 65,304 U.S. white radiologic technologists who responded to the baseline questionnaire survey in 1983-1989 and the follow-up survey in 1994-1998. Cox's proportional-hazards model was used to estimate relative risks of BCC and SCC associated with surrogate measures of occupational exposure to IR and residential UVR exposure during childhood and adulthood, adjusted for potential confounders including pigmentation characteristics. Relative risks of BCC, but not of SCC, were elevated among technologists who first worked during the 1950s (RR = 1.42; 95% CI = 1.12-1.80), 1940s (RR = 2.04; 95% CI = 1.44-2.88) and before 1940 (RR = 2.16; 95% CI = 1.14-4.09), when IR exposures were high, compared to those who first worked after 1960 (p for trend < 0.01). The effect of year first worked on BCC risk was not modified by UVR exposure, but was significantly stronger among individuals with lighter compared to darker eye and hair color (p = 0.013 and 0.027, respectively). This study provides some evidence that chronic occupational exposure to IR at low to moderate levels can increase the risk of BCC, and that this risk may be modified by pigmentation characteristics.     

Use of recombinant human chorionic gonadotropin in ovulation induction

To review the use of hCG and to describe the clinical benefit of recombinant hCG (r-hCG) based on the published results of prospective, randomized studies.Review of published articles.Tertiary infertility care center.None.None.Oocyte number and quality, luteal phase progesterone, pregnancy and OHSS rate, and local tolerability.The published data consistently show that single doses of 250 microg r-hCG and 5,000 IU urinary (u)-hCG produce similar clinical outcomes when used in infertility treatment cycles for timed intercourse, IUI, and IVF in terms of the number of oocytes retrieved, number of mature oocytes harvested, and fertilization and pregnancy rates attained. Single doses of 10,000 IU u-hCG also gave results comparable to single doses of 250 microg r-hCG. P levels in the midluteal phase were significantly higher with the use of r-hCG compared with u-hCG, and local injection site adverse effects were significantly less frequent, demonstrating the higher purity of the recombinant product. A single 500-microg dose of r-hCG led to a higher rate of ovarian hyperstimulation syndrome compared with a 250-microg dose, with no significant improvement in pregnancy rates.A single dose of 250 microg r-hCG was at least as effective as single doses of 5,000 or 10,000 IU u-hCG but offered the advantages associated with use of a recombinant product: local injection site adverse effects were significantly less frequent with r-hCG than with u-hCG.     

Changes in the phenotype of T-cell subset determinants following murine cytomegalovirus infection

The murine model provides a particularly apt experimental system in which to evaluate the effects of cytomegalovirus (CMV) infection. CMV exerts a profound "suppression" of the immune response in the mouse and in humans; the infected animal is no longer able to mediate an appropriate response to mitogens or alloantigens. Using fluorocytometry and fluoresceinated monoclonal antibodies directed against the Thy-1.2, Lyt-1, and Lyt-2 cell membrane determinants following a nonlethal intraperitoneal inoculation of weanling BALB/c mice with Smith strain murine cytomegalovirus, significant changes in T-cell subsets were found that are consistent with findings described in the clinical situation. These ratio changes are temporally consistent with the cytotoxic T-lymphocyte population described by others. Finally, novel changes in the antigenic determinant distribution is found which may reflect the appearance of an antigen-committed cytotoxic T-lymphocyte population. This population which peaks at the ninth postinfection day may consist of 20-47% of the T-lymphocyte population and may offer an explanation for the cellular hyporesponsiveness seen following CMV infection.     

Plasma sphingomyelins are associated with cognitive progression in Alzheimer's disease

Plasma sphingolipids have been shown to predict cognitive impairment and hippocampal volume loss, but there is little research in patients with Alzheimer's disease (AD). In this study we sought to determine whether plasma ceramides, dihydroceramides (DHCer), sphingomyelins (SM), or dihydrosphingomyelin (DHSM) levels and ratios of SM/ceramide or DHSM/DHCer were predictive of progression in AD. Probable AD patients (n = 120) were enrolled in the Alzheimer's Disease and Memory Disorders Center at Baylor College of Medicine. Plasma sphingolipids were assessed using ESI/MS/MS. Linear mixed effects models were used to examine the relation between baseline plasma sphingolipid levels and cross-sectional and longitudinal performance on the Mini-Mental State Exam (MMSE), Alzheimer's Disease Assessment Scale-Cognitive Subscale (ADAS-Cog), and Clinical Dementia Rating-Sum of Boxes (CDR-Sum). Participants were followed a mean of 4.2 visits and 2.3 years. There were no cross-sectional associations. In longitudinal analyses, high levels of DHCer and ceramide were associated with greater progression, but findings did not reach significance (p > 0.05). In contrast, higher plasma levels of SM, DHSM, SM/ceramide, and DHSM/DHCer ratios were associated with less progression on the MMSE and ADAS-Cog; the ratios were the strongest predictors of clinical progression. Compared to the lowest tertiles, the highest tertiles of DHSM/DHCer and SM/ceramide ratios declined 1.35 points (p = 0.001) and 1.19 (p = 0.004) points less per year on the MMSE and increased 3.18 (p = 0.001) and 2.42 (p = 0.016) points less per year on the ADAS-Cog. These results suggest that increased SM/ceramide and DHSM/DHCer ratios dose-dependently predict slower progression among AD patients and may be sensitive blood-based biomarkers for clinical progression.     

Diltiazem reduces pulmonary arterial pressures in recurrent pulmonary hypertension associated with pulmonary hypoplasia.

BACKGROUND/PURPOSE: Recurrent pulmonary hypertension in the neonatal population is an unusual event with dire consequences. Pulmonary hypertension seen in association with pulmonary hypoplasia may be refractory to conventional medical management. The effect of the calcium channel antagonist diltiazem was studied in five patients with severe pulmonary hypertension. METHODS: A retrospective review of the hospital records was performed to determine the efficacy of diltiazem for refractory pulmonary hypertension. All five patients experienced and did not respond to maximal conventional therapy, which included inhaled nitric oxide, intravenous nitrates, and extracorporeal membrane oxygenation (ECMO). Right ventricular pressures were determined by transthoracic echocardiograms and were used to document improvement in the pressure gradients. Statistical analyses were performed using a paired Student's ttest. A P value of less than .05 was considered significant. RESULTS: Diltiazem significantly reduced the right ventricular systolic pressure (RVSP) from 82 +/- 8.4 mm Hg to 58.4 +/- 7 mm Hg (P = .008). Two patients died; one had a large ventricular septal defect, and the other suffered multisystem organ failure secondary to sepsis. The surviving patients were weaned off diltiazem and did not experience recurrent pulmonary hypertension. CONCLUSIONS: In cases of pulmonary hypoplasia with recurrent pulmonary hypertension, diltiazem may be considered as a therapy. A multicenter prospective trial is advocated.     

The Alzheimer's Disease Assessment Scale-Cognitive subscale: normative data for older adult controls

The Alzheimer's Disease Assessment Scale-Cognitive subscale (ADAS-cog) is commonly used to assess cognitive dysfunction in individuals with Alzheimer disease and other dementias. The purpose of this study was to provide normative scores for the ADAS-cog 11 individual items and total score, as well for delayed recall errors, using normal, elderly volunteers. The ADAS-cog was administered to 124, non-cognitively impaired volunteers ages 55 to 89, with 10 to 21 years of education. The mean total ADAS-cog score was five. The ADAS-cog error score was not associated with education in this highly educated group, and was positively correlated (P < 0.001) with the age of the participant. Age stratified ADAS-cog normative data are reported for the ADAS-cog total and the delayed recall error score.