Serial procalcitonin levels to detect bacteremia in febrile neutropenia.

Background: Our objective was to evaluate serial procalcitonin (PCT) levels compared with an initial PCT level at admission in predicting bacteremia in pediatric febrile neutropenic oncology patients.

Procedure: Serum PCT levels were measured at admission (t0) and within 24 hours of admission (t1) in pediatric oncology patients presenting with fever and neutropenia. A blood culture was collected at t0 and monitored for 5 days for bacterial growth.

Five additional Costello syndrome patients with rhabdomyosarcoma: proposal for a tumor screening protocol.

We report five new cases of rhabdomyosarcoma (RMS) in Costello syndrome. These cases, combined with those previously reported, increase the number of solid tumors to 17 (10 RMSs, 3 neuroblastomas, 2 bladder carcinomas, 1 vestibular schwannoma, 1 epithelioma), in at least 100 known Costello syndrome patients. Despite possible ascertainment bias, and the incomplete identification of all Costello syndrome patients, the tumor frequency could be as high as 17%.

Sulfate activation and transport in mammals: system components and mechanisms.

Extensive studies on the mammalian sulfate-activating enzymes and PAPS translocase have enhanced our understanding of the overall pathway of sulfate activation and utilization. Isolation of the PAPS-synthesizing activities from rat chondrosarcoma and preparation of stable non-hydrolyzable analogs of APS and PAPS have facilitated the kinetic characterization of mammalian ATP sulfurylase and APS kinase. These studies provided the basis for further experimental work showing that APS, the labile intermediate product, is channeled directly between the sulfurylase and kinase active sites.

Identification and partial purification of PAPS translocase.

Sulfation of all macromolecules in higher organisms requires the high-energy donor 3'-phosphoadenosine 5'-phosphosulfate (PAPS). PAPS is synthesized via the sequential actions of two cytoplasmic enzymes, ATP sulfurylase and APS kinase, and then must be transferred across the Golgi membrane for utilization by lumenal sulfotransferases. Following the kinetic characterization of the PAPS translocase as a specific transporter that act through an antiport mechanism with PAP as the returning ligand [Ozeran, J.

Kinetics of PAPS translocase: evidence for an antiport mechanism.

In order to gain an understanding of the mechanisms involved in the transfer of 3'-phosphoadenosine 5'-phosphosulfate (PAPS) from the cytosol where it is synthesized to the Golgi lumen where it serves as the universal sulfate donor for sulfate ester formation in higher organisms, we have undertaken a kinetic characterization of the PAPS translocase from rat liver Golgi. Analyzing the PAS translocase activity in both intact Golgi vesicles and in a reconstituted liposome system, we have determined a number of physical and kinetic parameters. Strong competitive inhibition in zero-trans uptake experiments only with beta-methylene PAPS and adenosine 3',5'-biphosphate (PAP) suggest the transporter is highly specific for the 3'-phosphate.

Intermediate channeling between ATP sulfurylase and adenosine 5'-phosphosulfate kinase from rat chondrosarcoma.

Biosynthesis of the activated sulfate donor PAPS (3'-phosphoadenosine 5'-phosphosulfate) involves the sequential action of two enzyme activities. ATP sulfurylase catalyzes the formation of APS (adenosine 5'-phosphosulfate) from ATP and free sulfate, and APS is then phosphorylated by APS kinase to produce PAPS. Using rat chondrosarcoma ATP sulfurylase and APS kinase, a newly developed assay system, which permits measuring the accumulation of both APS and PAPS in the presence of both enzyme activities, produces a PAPS/APS ratio corresponding to a "channeling efficiency" of 96%.

Historical demographic and epidemiological studies of aging in American Samoans.

American Samoan mortality records, from 1920 through 1988, and epidemiological survey data from 1976 are used to examine demographic definitions of the elderly in different time periods and to examine the association of body habitus and blood pressure with mortality among middle-aged and older Samoans. In the 1920s, the average Samoan lived 24 years, but over 50% of deaths occurred prior to age 15. In the 1980s the average Samoan lived about 54 years and 50% of deaths occurred after age 58.