A mouse model for the delta F508 allele of cystic fibrosis.

The most common cause of cystic fibrosis is a mutation that deletes phenylalanine 508 in cystic fibrosis transmembrane conductance regulator (CFTR). The delta F508 protein is misprocessed and degraded rather than traveling to the apical membrane. We used a novel strategy to introduce the delta F508 mutation into the mouse CFTR gene. Affected epithelia from homozygous delta F508 mice lacked CFTR in the apical membrane and were Cl-impermeable. These abnormalities are the same as those observed in patients with delta F508 and suggest that these mice have the same cellular defect. 40% of homozygous delta F508 animals survived into adulthood and displayed several abnormalities found in human disease and in CFTR null mice. These animals should provide an excellent model to investigate pathogenesis and to examine therapies directed at correcting the delta F508 defect.     

Dysuria,heat stress,and muscle injury among Nicaraguan sugarcane workers at risk for Mesoamerican nephropathy

Objectives:Nicaraguan sugarcane workers, particularly cane cutters, have an elevated prevalence of chronic kidney disease of unknown origin, also referred to as Mesoamerican nephropathy (MeN). The pathogenesis of MeN may include recurrent heat stress, crystalluria, and muscle injury with subsequent kidney injury. Yet, studies examining the frequency of such events in long-term, longitudinal studies are limited.Methods:Using employment and medical data for male workers at a Nicaraguan sugarcane company, we classified months of active work as either work as a cane cutter or other sugarcane job and determined occurrence of dysuria, heat events and muscle events. Work months and events occurred January 1997 to June 2010. Associations between cane cutting and each outcome were analyzed using logistic regression based on generalized estimating equations for repeated events, controlling for age.Results:Among 242 workers with 7257 active work months, 19.5% of person-months were as a cane cutter. There were 160, 21, and 16 episodes of dysuria, heat events, and muscle events, respectively. Compared with work months in other jobs, cane cutting was associated with an elevated odds of dysuria [odds ratio 2.40 (95% confidence interval 1.56–3.68)]. The number of heat and muscle events by cane cutter and other job were limited.Conclusions:Working as a cane cutter compared with other jobs in the sugarcane industry was associated with increased dysuria, supporting the hypothesis that cane cutters are at increased risk of events suspected of inducing or presaging clinically evident kidney injury.     

Reading performance of geriatric patients post exudative maculopathy.

This study was performed to evaluate any differences in reading speed and duration of comfortable reading speed in geriatric patients with post disciform stage exudative age-related macular degeneration (ARMD) or ocular histoplasmosis. Reading speed and duration with CCTV, illuminated stand magnifier, and spectacle lenses were compared for 37 patients in the Low Vision Program at the Central Blind Rehabilitation Center. Results indicate significantly faster reading speed with CCTV and spectacle lenses as compared to illuminated stand magnifiers. The difference between reading speeds measured with spectacle reading glasses and CCTVs was borderline significant. Patients read significantly longer with CCTVs than with spectacle lenses or illuminated stand magnifiers. No significant difference was found comparing spectacle lenses or illuminated stand magnifiers with regard to reading duration.     

Youth at risk. Sex, drugs, and human immunodeficiency virus.

Adolescents and young adults are at risk for human immunodeficiency virus type 1 infection due to unprotected sexual intercourse and drug use. In 1988 and 1989, blinded surveys were conducted in 84 sexually transmitted disease clinics, 115 women's health clinics, and 19 drug treatment centers in 38 metropolitan areas. Blood specimens from 153,242 clients, aged 15 to 24 years, were tested for human immunodeficiency virus type 1 antibodies after all client identifiers were removed. In sexually transmitted disease clinics, the median rate was 0.4% among 15- to 19-year-olds, compared with 1.4% among 20- to 24-year-olds. Among heterosexual adolescents, rates in females were significantly higher than in males (Wilcoxon signed rank test). Rates in heterosexuals were highest in the northeastern and southeastern United States and in Puerto Rico. In 20- to 24-year-old male clients in sexually transmitted disease clinics who had sex with males, rates ranged from 9.7% to 55.6%. In drug treatment centers, the median rate among 20- to 24-year-old men and women was 8.3% (range, 0% to 33.3%). Rates in women's health clinics were much lower (median, 0.1%). The high rates of infection in certain groups of adolescents and young adults indicate the need for improved care, education, and outreach targeted toward those at high risk.     

Completeness of tuberculosis case reporting,San Juan and Caguas Regions,Puerto Rico, 1992.

Completeness of tuberculosis case reporting in Puerto Rico was assessed. Cases diagnosed among hospitalized, tuberculosis, and human immunodeficiency virus clinic patients during 1992 were retrospectively reviewed. Hospital discharge diagnoses, pharmacy listings of patients receiving anti-tuberculous medications, laboratory and acquired immunodeficiency syndrome registry data were used for case finding in selected hospitals and clinics. Identified cases were matched to the health department TB case registry to determine previous reporting through routine surveillance. Records of unreported cases were reviewed to verify tuberculosis diagnoses. Of 159 patients with tuberculosis, 31 (19.5%) were unreported. A case was defined according to the Centers for Disease Control and Prevention definition. Unreported cases were less likely than previously reported cases to have specimens that were culture positive for M. tuberculosis, 14 of 31 (45.2%) compared with 111 of 128 (86.7%). Excluding the laboratory, tuberculosis diagnoses in acquired immunodeficiency syndrome registry patients had the highest predictive value of finding tuberculosis (94.1%), followed by tuberculosis clinic records (71.7%), and pharmacy listings (45.6%). Tuberculosis discharge diagnoses, however, yielded the largest number of unreported cases (14). Health care providers should be educated regarding the importance of promptly reporting all suspected TB cases regardless of results of laboratory testing.