In the Eye of the Storm: Bioethics in the Time of COVID-19

HSS Journal ® -     

Trends in CT scan rates in children and pregnant women: teaching,private, public and nonprofit facilities

Background

Radiation exposure from medical sources now equals or exceeds that from natural background sources, largely attributable to a 20-fold increase in CT use since 1980. Increasing exposure to children and fetuses is of most concern due to their heightened susceptibility. More recently, CT use may be leveling or decreasing, but it is unclear whether this change is widespread or varies by type of institution.

Objective

We sought to characterize trends in CT utilization in California hospitals and emergency departments among children and pregnant women, looking at different types of facilities, such as teaching, private, public and nonprofit institutions.

Materials and methods

We examined frequency of CT examinations by year from 229 facilities reporting CT usage in routinely collected California statewide data for 2005–2012. We modeled trends overall and by facility type.

Results

CT scans for pediatric and pregnant patient visits in the emergency department increased initially, then started to decline after 2008. Among hospital admissions, rates declined or leveled after 2005. In the emergency department, CT rates varied between types of facilities, with teaching hospitals reducing use sooner and more sharply than other types of facilities.

Conclusion

CT utilization in California among children and pregnant women has begun to level or decline. Still, population exposure remains at historically high levels, warranting consideration of potential public health implications. Further examination of reasons for trends among hospital types, particularly how teaching hospitals have reduced rates of CT utilization, may help identify strategies for CT reduction without compromising patient care.     

Purine Nucleoside Phosphorylase Deficiency: EVIDENCE FOR MOLECULAR HETEROGENEITY IN TWO FAMILIES WITH ENZYME-DEFICIENT MEMBERS

Purine-nucleoside phosphorylase (NP) deficiency is associated with severely defective thymus-derived (T)-cell and normally functioning bone marrow-derived (B)-cell immunity. In this study, two unrelated families with a total of three NP deficient members were investigated.High pressure liquid chromatography of the plasma of the three patients showed inosine levels greater than 66 muM. This nucleoside was absent from the plasma of their parents and control samples.NP was purified from normal human erythrocytes by affinity chromatography and an antiserum prepared in rabbits was used to study the NP variants in the two families.In family M the patient had no detectable erythrocyte NP activity and no detectable immunological-reacting material (irm) to the NP antibody. The parents, who are second cousins, had less than one-half of normal enzyme activity and approximately 14% irm attributable to a variant protein. Their electrophoretic patterns revealed a series of isozymes with slower than normal migration.In family B the patients had 0.5% residual enzyme activity and about one-half normal irm. Their electrophoretic pattern showed faintly staining bands which migrated faster than normal NP. The mother of the patients had one-half normal enzyme activity, 11% irm attributable to her variant protein, and a normal electrophoretic pattern. The father had less than one-half normal enzyme activity, equal amounts of normal and variant irm, and an electrophoretic pattern that showed increased activity of the more rapidly migrating isozyme bands.The combined use of immunological and electrophoretic techniques has shown the presence of three separate mutations; one in family M and two in family B associated with severely defective T-cell function.     

Small Airways in Idiopathic Pulmonary Fibrosis: COMPARISON OF MORPHOLOGIC AND PHYSIOLOGIC OBSERVATIONS

18 patients with idiopathic pulmonary fibrosis were studied to determine if they had morphologic evidence of small airways disease and if physiologic testing could predict morphologic findings. In the presence of normal airway function by standard physiologic studies (forced expiratory volume in 1 s/forced vital capacity and airway resistance by plethysmography), dynamic compliance, maximum expiratory flow-volume curves, and maximum flowstatic recoil curves were measured to detect physiologic alterations consistent with small airways abnormalities. These physiologic data were then compared with estimates of small airways diameter made in lung biopsy specimens.     

Antifungal Activity of 3′-Deoxyadenosine (Cordycepin)

The antifungal activity of the nucleoside analog 3′-deoxyadenosine (cordycepin) was studied in a murine model of invasive candidiasis. When protected from deamination by either deoxycoformycin or coformycin, both of which are adenosine deaminase inhibitors, cordycepin exhibited potent antifungal efficacy, as demonstrated by prolongation of survival and a decrease in CFU in the kidneys of mice treated with cordycepin plus an adenosine deaminase inhibitor. The antifungal effect was seen with three different Candida isolates: Candida albicans 64, a relatively fluconazole-resistant clinical isolate of C. albicans (MIC, 16 μg/ml), and the fluconazole-resistant Candida krusei. Cordycepin and related compounds may provide another avenue for the discovery of clinically useful antifungal drugs.