Human plasma transport of vitamin D after its endogenous synthesis.

Transport of vitamin D3 from its sites of cutaneous synthesis into the circulation has been assumed to be via the plasma vitamin D binding protein (DBP). We studied vitamin D transport from the skin in seven healthy volunteers who received whole body irradiation with 27 mJ/cm2 dosage of ultraviolet B light (290-320 nm). Samples of venous blood were collected serially in EDTA and immediately chilled. In KBr, plasma samples were ultracentrifuged to provide a rapid separation of proteins of density < and > 1.3 g/ml. Upper and lower phases and serial fractions were analyzed for vitamin D3 (extraction, HPLC), cholesterol (enzyme assay), and human DBP (hDBP) (radial immunodiffusion). Total plasma vitamin D (basal level < 1 ng/ml) increased by 10 h and peaked at 24 h (9 +/- 1 ng/ml). 98% of the D3 remained at the density > 1.3 layers for up to 7 d, whereas cholesterol (> 85%) was detected at density < 1.3 and all of the hDBP was at density > 1.3. In three volunteers who each ingested 1.25 mg of vitamin D2, the total plasma D2 increased to 90 +/- 32 ng/ml by 4 h, and the D2 was evenly distributed between the upper and lower layers at 4, 8, and 24 h after the dose, indicating a continuing association of the vitamin with chylomicrons and lipoproteins, as well as with hDBP. Actin affinity chromatography removed D3 from plasma of irradiated subjects, indicating the association of the D3 with DBP. These findings indicate that endogenously synthesized vitamin D3 travels in plasma almost exclusively on DBP, providing for a slower hepatic delivery of the vitamin D and the more sustained increase in plasma 25-hydroxycholecalciferol observed after depot, parenteral administration of vitamin D. In contrast, the association of orally administered vitamin D with chylomicrons and lipoproteins allows for receptor-mediated, rapid hepatic delivery of vitamin D, and the reported rapid but less-sustained increases in plasma 25-hydroxycholecalciferol.     

Comparison study of full and subthreshold bulimia nervosa: Personality,clinical characteristics,and short-term response to therapy

Abstract

This study compared symptomatological and personality differences between individuals with threshold bulimia nervosa (BN; n=39) and those with subthreshold BN (n=39) and their short-term response to a brief outpatient intervention. Participants were matched using a pairwise matching procedure, taking into account age, age of onset, and duration of the disorder. Both groups received the same brief outpatient psychoeducational therapy. The same assessment measures were used before and after treatment. With the exception of some clinical and psychopathological symptoms (higher depression and phobic anxiety in threshold BN), there were no significant between-group differences on scales of general psychopathology or personality traits. At the end of treatment, there were no significant between-group differences on abstinence rates for binge eating and vomiting, number of sessions attended, or dropout rates. Threshold BN and subthreshold BN share common psychopathological symptoms and personality traits. No differences in therapy outcome were observed for the two groups after a brief group psychoeducational intervention.     

Deploying an HMO's data warehouse

Kaiser Permanente says it has saved millions of dollars and improved the quality of care with information from its data warehouse. Here's how Kaiser implemented the warehouse four years ago, and how it uses it today.     

The impact of pre-radiotherapy surgery on radiation-induced lung injury

AimsThe use of postoperative radiation therapy (PORT) is predicated by an assessment of the potential benefits and risks, including radiation-induced lung injury. In this study, the risk of radiation-induced lung injury is assessed in patients who received PORT, and compared with a group of patients who received radiation without prior surgery, to determine if surgery increases the risk of radiation pneumonitis.Materials and methodsFrom 1991 to 2003, 251 patients with lung cancer were enrolled into a prospective study to assess radiation-induced lung injury. All patients received three-dimensional-planned, external-beam radiotherapy. One hundred and seventy-seven patients with over 6-months follow-up were eligible. For the current analysis, 49 patients (28%) had surgical intervention before radiotherapy. The rates of Grade 2 symptomatic pneumonitis in subgroups, based on the type of pre-radiation surgery, were computed and compared using Fisher's Exact Test. To consider the confounding factor of irradiated lung volume, patient subgroups were further defined on the basis of the mean lung dose.ResultsSurgical procedures included pneumonectomy (n = 9), lobectomy (n = 16), wedge resection (n = 8) and exploration without resection (n = 16). Radiation-induced lung injury occurred in 33 out of 177 (19%) patients, including 18% of the surgical group and 19% of the non-surgical group. Additionally, no statistically significant difference was found in the rate of radiation-induced lung injury based on the extent of resection.ConclusionsThe incidence of pneumonitis is similar in the surgical and non-surgical groups. Thus, PORT may be safely given to selected patients after surgical exploration or resection.