Oxysterols induce differentiation in human keratinocytes and increase Ap-1-dependent involucrin transcription

Ligands and activators of the nuclear hormone receptor superfamily are important in the regulation of epidermal development and differentiation. Previously, we showed that naturally occurring fatty acids, as well as synthetic ligands for the peroxisome proliferator-activated receptor, induce keratinocyte differentiation in vitro. Here we asked whether oxysterols, another class of lipids formed de novo in the epidermis and that activate liver X-activated receptor, regulate keratinocyte differentiation. mRNA and protein levels of involucrin and transglutaminase 1, markers of differentiation, increased 2- to 3-fold in normal human keratinocytes incubated in the presence of 25- or 22R-hydroxycholesterol in low calcium. In high calcium, which alone induces differentiation, mRNA levels were further increased by oxysterols. Rates of cornified envelope formation, an indicator of terminal differentiation, also increased 2-fold with oxysterol treatment. In contrast, the rate of DNA synthesis was inhibited approximately 50% by oxysterols. Transcriptional regulation was assessed in keratinocytes transfected with either transglutaminase 1 or involucrin promoter-luciferase constructs. 22R-hydroxycholesterol increased transglutaminase 1 and involucrin promoter activity 2- to 3-fold. Either deletion of the -2452 bp to -1880 bp region of the involucrin promoter, or mutation of the AP-1 site within this region, abolished oxysterol responsiveness. Moreover, increased AP-1 DNA binding was observed in oxysterol-treated keratinocytes by gel shift analyses. Finally, we demonstrated the presence of liver X-activated receptor alpha and beta mRNAs, and showed that oxysterols stimulate a liver X-activated receptor response element transfected into keratinocytes. These data suggest that oxysterols induce keratinocyte differentiation, in part through increased AP-1-dependent transcription of the involucrin gene, an effect that may be mediated by liver X-activated receptor.

Fetal epidermal differentiation and barrier development In vivo is accelerated by nuclear hormone receptor activators

Nuclear receptors which interact with the retinoid X receptor are involved in the regulation of epidermal differentiation and development. We have recently shown that activators of the peroxisome proliferator-activated receptor and of the farnesoid X-activated receptor accelerate epidermal barrier maturation in fetal rat skin in vitro. In this study we asked whether cutaneous development in utero was affected by peroxisome proliferator-activated receptor or farnesoid X-activated receptor activators, or by an activator of another retinoid X receptor partner, liver X receptor. Activators of the peroxisome proliferator-activated receptor (clofibrate or linoleic acid), farnesoid X-activated receptor (farnesol or juvenile hormone III), or liver X receptor (22R-hydroxycholesterol), were injected into the amniotic fluid of fetal rats on gestational day 17. Fetal epidermal barrier function and morphology was assessed on day 19. Whereas vehicle-treated fetal rats displayed no measurable barrier (transepidermal water loss > 10 mg per cm2 per h), a measurable barrier was induced by the intra-amniotic administration of all activators tested (transepidermal water loss range 4.0-8.5 mg per cm2 per h). By light microscopy, control pups lacked a well-defined stratum corneum, whereas a distinct stratum corneum and a thickened stratum granulosum were present in treated pups. By electron microscopy, the extracellular spaces of the stratum corneum in control pups revealed a paucity of mature lamellar unit structures, whereas these structures filled the stratum corneum interstices in treated pups. Additionally, protein and mRNA levels of loricrin and filaggrin, two structural proteins of stratum corneum, were increased in treated epidermis, as were the activities of two lipid catabolic enzymes critical to stratum corneum function, beta-glucocerebrosidase and steroid sulfatase. Finally, peroxisome proliferator-activated receptor-alpha and -delta and liver X receptor-alpha and -beta mRNAs were detected in fetal epidermis by reverse transcriptase-polymerase chain reaction and northern analyses. The presence of these receptors and the ability of their activators to stimulate epidermal barrier and stratum corneum development suggest a physiologic role for peroxisome proliferator-activated receptor and liver X receptor and their endogenous ligands in the regulation of cutaneous development.

Drug use, AIDS knowledge, and HIV risk behaviors of Cuban-, Mexican-, and Puerto-Rican-born drug injectors who are recent entrants into the United States

To date, relatively little research attention has been devoted to the HIV-risky behaviors of persons who are newly arrived in the United States and who use drugs. Data gathered from street-recruited injection drug users (IDUs) recruited in 10 United States cities who were born in Mexico, Cuba, and Puerto Rico and who are recent entrants into the United States suggest that, in comparison to US-born IDUs, Mexican-born subjects are at elevated risk for acquiring and transmitting HIV as a result of sharing needles with friends and running partners; sharing drug injection implements such as cookers, cotton, and rinse water; frequent injection in HIV-risky settings; use of unsterilized needles; and relatively frequent trading of sex for drugs or money. Puerto-Rican-born IDUs were found to inject drugs relatively frequently, and to do so relatively often in high-risk settings in which sterile injecting equipment and cleaning materials often are scarce. These data also show generally lower levels of AIDS knowledge among the in-migrant IDUs than among US-born IDUs. Respondents from each nationality group most often cited television as the source of their most useful and reliable AIDS information, but also tended to regard community outreach workers as a significant source of reliable AIDS and needle cleaning information. The high levels of involvement in HIV-risky behaviors, deficits in knowledge concerning the means of HIV transmission, and relative ease of mobility of the at-risk (for HIV) individuals examined here indicate a need for a comprehensive public health prevention initiative to limit the future spread of HIV. At a minimum, such an undertaking would do well to incorporate group-specific, culturally appropriate behavioral interventions as well as an information campaign.

Analysis of a petrol plume over England: 18-19 January 1997

OBJECTIVES

About 7000 tonnes of unleaded petrol were discharged into the English Channel after a tanker collision off Ostend on Saturday 18 January 1997. The petrol evaporated and the vapour plume was carried across the central part of England to Wales, resulting in reports of unidentified odours, and irritation of the eyes, skin, and upper respiratory tract. This work uses this incident to show how marine and atmospheric dispersion modelling together with routine air quality monitoring can assist in identifying hazards to the population at risk from chemical incidents.

METHODS

Public health surveillance and results from environmental sampling were compared with the behaviour of the plume as predicted by computer modelling.

RESULTS

The predicted plume path and dispersion were shown to correlate well with the results from surveillance and environmental analysis.

CONCLUSIONS

There is a need for public health professionals to interact with medical toxicologists, atmospheric and marine scientists and engineers, and other environmental experts in managing events of this nature.

Neonatal erosions and ulcerations in giant congenital melanocytic nevi

We report 10 cases of neonatal erosions or ulcerations in giant congenital melanocytic nevi. Histopathologic examination, performed in eight cases, demonstrated benign findings. Clinical follow-up for an average of 3.8 years (range 2 weeks to 8 years) has not revealed the development of cutaneous melanoma. We conclude that erosions or ulcerations in giant melanocytic nevi in neonates are often benign and do not necessarily signify the presence of cutaneous melanoma.

Cyclophosphamide versus ifosfamide: to use ifosfamide or not to use, that is the three-dimensional question

Ifosfamide and cyclophosphamide are alkylating agents that are extensively used in the clinical treatment of cancer. However, the continued use of ifosfamide has been questioned with the suggestion that cyclophosphamide be used exclusively. One response to this proposal is based upon the fact that both cyclophosphamide and isfosfamide are chiral and are administered as racemic (50:50) mixtures of the two isomers. Studies of the clinical pharmacology, metabolism and disposition of these agents indicate that stereochemistry plays a minor role in the efficacy and toxicity of cyclophosphamide but is a major factor in neurotoxicity associated with ifosfamide administration. Studies have demonstrated that the use of a single ifosfamide enantiomer, (R)-ifosfamide would retain the unique antitumor efficacy of this agent, while eliminating the major source of the observed ifosfamide-associated neurotoxicity, (S)-ifosfamide.

Enantioselective induction of cyclophosphamide metabolism by phenytoin

The objective of this study was to investigate the effect of phenytoin (PHE) on cyclophosphamide (CP) disposition. CP was administered to 6 adult patients in a preparative regimen for bone marrow transplantation consisting of busulfan and CP. Three of the patients received PHE and the other 3 "control" patients received diazepam (DZP) as anti-epileptic prophylactic treatment. Plasma samples were collected at intervals up to 24 h after CP administration. The plasma concentrations of (R)- and (S)-CP and their respective N-dechloroethylated metabolites, (R)- and (S)-DCE-CP were simultaneously fitted using an enantiospecific 2-compartment pharmacokinetic (PK) model with Bayesian control estimation. DZP had no significant effect on the metabolism of CP and any of its PK parameters. PHE, however, increased significantly the formation of (S)-DCE-CP while having no effect on the formation of (R)-DCE-CP. These results suggest that different enzymes are responsible for the formation of (S)-DCE-CP from (S)-CP and (R)-DCE-CP from (R)-CP. Additionally, assuming that PHE does not affect the passive renal elimination of (R)- and (S)-CP, this analysis suggests that the clearance of both (R)- and (S)-CP to 4-hydroxy-CP (the activation pathway) is increased by PHE.

Altered lamellar body secretion and stratum corneum membrane structure in Netherton syndrome: differentiation from other infantile erythrodermas and pathogenic implications

BACKGROUND

The infant with Netherton syndrome (NS) typically displays a generalized erythroderma covered by fine, translucent scales, which can be difficult to distinguish clinically from erythrodermic psoriasis, nonbullous congenital ichthyosiform erythroderma, or other infantile erythrodermas. Some infants with NS develop progressive hypernatremic dehydration, failure to thrive, and enteropathy. Such complications can be fatal. Diagnosis is typically delayed until the appearance of a pathognomonic hair shaft anomaly, trichorrhexis invaginata (bamboo hair). To facilitate the early diagnosis of NS, we obtained biopsy specimens from 7 patients with erythrodermic NS and compared their morphologic findings to those of 3 patients with erythrodermic psoriasis and 2 with congenital ichthyosiform erythroderma. Biopsy specimens were processed for light and electron microscopy using postfixation with osmium tetroxide and ruthenium tetroxide.

OBSERVATION

In NS, and often in congenital ichthyosiform erythroderma and erythrodermic psoriasis, the stratum corneum layer was largely replaced by parakeratotic cells. A distinctive feature--premature secretion of lamellar body contents--occurred only in NS. Furthermore, lamellar body-derived extracellular lamellae and stratum corneum lipid membranes were separated extensively by foci of electron-dense material. Finally, transformation of lamellar body-derived lamellae into mature lamellar membrane structures was disturbed in NS.

CONCLUSIONS

Premature lamellar body secretion and foci of electron-dense material in the intercellular spaces of stratum corneum, features not observed in other erythrodermic disorders, appear to be frequent and relatively specific markers for NS. These ultrastructural features could permit the early diagnosis of NS before the appearance of the hair shaft abnormality. These abnormalities could explain the impaired permeability barrier in NS, and account for hypernatremia and dehydration in infants with NS.

Auditory recall and response to command during recovery from propofol anaesthesia

Most studies of awareness under general anaesthesia use the ability to respond to a verbal command as the primary measure of consciousness. The aim of this pilot study was to discover whether it was possible for subjects recovering from a propofol general anaesthetic to experience conscious awareness without the capability of responding to verbal command. Ten healthy volunteers received an intravenous propofol infusion (1500 mg/hr) until they were no longer conscious. The infusion was then stopped and they were given verbal commands interspersed with random numbers from a recorded tape until they were able to respond appropriately. Seven of the subjects were able to remember numbers corresponding to times 10 to 40 seconds before they responded to verbal command. In none of these subjects was there recall of the number 30 minutes later. We concluded that there is an ability to have conscious awareness of auditory input without necessarily being able to demonstrate this by responding to verbal command.

Pharmacokinetics of (R)- and (S)-cyclophosphamide and their dechloroethylated metabolites in cancer patients

The complete pharmacokinetics (PK) of (R)- and (S)-cyclophosphamide (CP) and their dechloroethylated (DCE) metabolites have not been reported to date. We collected plasma and urine samples from 12 cancer patients and determined concentrations of both enantiomers of CP and DCE-CP using a chiral GC-MS method. All concentrations of (R)-CP, (S)-CP, (R)-DCE-CP, and (S)-DCE-CP were simultaneously modeled using an enantiospecific compartmental PK model. A population PK analysis was performed. Enantiospecific differences between (R)- and (S)-CP were found for the formation clearance of CP to the DCE metabolites (Clf: 0.25 (R) vs. 0.14 (S) L/h). No difference was found between enantiomers for Cl40H, Cld, Cl(m)R, ClT, or T1/2. In contrast to the adolescent and adult group of patients, a child (6 years old) appeared to have a very different PK and metabolic profile (Bayesian control analysis). Proportions of the (R,S)-CP doses transformed to the (R)-DCE- and (S)-DCE-CP were much higher (R: 25 vs. 1.9%, and S: 38 vs. 3.6%), while formation of active metabolites was much lower (R: 42 vs. 74%, and S: 48 vs. 77%). CP appears to be enantioselectively metabolized to the DCE metabolites. This PK model can evaluate the proportion of a CP dose that is transformed to toxic or active metabolites. It may therefore be used to optimize CP treatment, to identify important drug interactions and/or patients with an abnormal metabolic profile.

Induction of selected lipid metabolic enzymes and differentiation-linked structural proteins by air exposure in fetal rat skin explants

The epidermal permeability barrier of premature infants matures rapidly following birth. Previous studies suggest that air exposure could contribute to this acceleration, because: (i) development of a structurally and functionally mature barrier accelerates when fetal rat skin explants are incubated at an air-medium interface, and (ii) occlusion with a water-impermeable membrane prevents this acceleration. To investigate further the effects of air exposure on epidermal barrier ontogenesis, we compared the activities of several key enzymes of lipid metabolism and gene expression of protein markers of epidermal differentiation in fetal rat skin explants grown immersed versus air exposed. The rate-limiting enzymes of cholesterol (HMG CoA reductase) and ceramide (serine palmitoyl transferase) synthesis were not affected. In contrast, the normal developmental increases in activities of glucosylceramide synthase and cholesterol sulfotransferase, responsible for the synthesis of glucosylceramides and cholesterol sulfate, respectively, were accelerated further by air exposure. Additionally, two enzymes required for the final stages of barrier maturation and essential for normal stratum corneum function, beta-glucocerebrosidase, which converts glucosylceramide to ceramide, and steroid sulfatase, which desulfates cholesterol sulfate, also increased with air exposure. Furthermore, filaggrin and loricrin mRNA levels, and filaggrin, loricrin, and involucrin protein levels all increased with air exposure. Finally, occlusion with a water-impermeable membrane prevented both the air-exposure-induced increase in lipid enzyme activity, and the expression of loricrin, filaggrin, and involucrin. Thus, air exposure stimulates selected lipid metabolic enzymes and the gene expression of key structural proteins in fetal epidermis, providing a biochemical basis for air-induced acceleration of permeability barrier maturation in premature infants.

Educate ICU assistive personnel

Many institutions use assistive personnel in intensive care units (ICUs) to provide more cost-effective nursing care. One ICU uses a comprehensive, competency-based orientation program to help fulfill the assistive personnel's unique orientation needs.

The acceptability of a computer HIV/AIDS risk assessment to not-in-treatment drug users

The purpose of this paper is to report the results of a study assessing the acceptability of a computer HIV risk assessment instrument administered to not-in-treatment drug users. The study asked three questions related to acceptability: (1) are drug users comfortable responding to HIV risk questions using the computer assessment; (2) do drug users feel that they possess the requisite skill to respond to questions using a computer; and (3) do drug users believe that the responses they provide using the computer assessment will remain private and confidential. This study differs from other assessments of the acceptability of computer assisted data collection in that the population of interest has only limited education and interaction with computers. Furthermore, the study was implemented under field conditions. To conduct the study, an existing HIV risk assessment instrument was adapted for use with the computer. Only slight modifications were made to the content of the instrument. To facilitate data collection with this population, audio enhancement and touch screen were used. Three scales measuring comfort, skill and perceived privacy were developed. Results of analysis showed that drug users are comfortable responding to an HIV risk assessment using computer assisted interviewing. Drug users also perceived that they possessed the requisite skill to successfully complete the interview. And, study participants reported that they believed that their responses using the computer interview would remain private and confidential. Only minor differences in scale scores based on sociodemographic characteristics were found among study participants. Implications of the findings are discussed.

Recessive x-linked ichthyosis: role of cholesterol-sulfate accumulation in the barrier abnormality

Cholesterol sulfate is a multifunctional sterol metabolite, produced in large amounts in squamous keratinizing epithelia. Because patients with recessive x-linked ichthyosis display not only a 10-fold increase in cholesterol sulfate, but also a 50% reduction in cholesterol, we assessed here whether cholesterol sulfate accumulation and/or cholesterol deficiency produce abnormal barrier function in recessive x-linked ichthyosis. Patients with recessive x-linked ichthyosis display both an abnormal barrier under basal conditions, and a delay in barrier recovery after acute perturbation, which correlate with minor abnormalities in membrane structure and extensive lamellar-phase separation. Moreover, both the functional and the structural abnormalities were corrected by topical cholesterol. Yet, topical cholesterol sulfate produced both a barrier abnormality in intact skin and extracellular abnormalities in isolated stratum corneum, effects largely reversed by coapplications of cholesterol. Together, these results suggest that cholesterol sulfate accumulation rather than cholesterol deficiency is responsible for the barrier abnormality. Despite the apparent importance of cholesterol sulfate-to-cholesterol processing for normal barrier homeostasis, neither steroid sulfatase activity nor mRNA levels are upregulated following acute perturbations. These results demonstrate both a potential role for cholesterol sulfate-to-cholesterol processing in normal permeability barrier homeostasis, and that basal levels of steroid sulfatase are sufficient to accommodate acute insults to the permeability barrier.

Ligands and activators of nuclear hormone receptors regulate epidermal differentiation during fetal rat skin development

Because a protective barrier is essential for life, the development of the epidermis and stratum corneum must be completed prior to birth. The epidermal permeability barrier is comprised of corneocytes embedded in a lipid enriched matrix. Recent studies from our laboratory, using an explant model of fetal rat skin development that closely parallels in utero development, have shown that hormones and other activators of members of the nuclear receptor family regulate permeability barrier ontogenesis by stimulating lipid metabolism and the formation of the extracellular lipid lamellae. Using this model we sought to determine whether these hormones and nuclear activators also regulate keratinocyte differentiation during fetal development. Profilaggrin/filaggrin and loricrin expression, assessed by in situ hybridization and by immunohistochemistry, were progressively increased during epidermal ontogenesis. Whereas profilaggrin/filaggrin and loricrin were not expressed at day 17 of gestation, by day 19 both were present in the upper layers of the epidermis and both became still more abundant by day 21. These developmental changes also occurred in fetal skin explants cultured in vitro for 4 d, although the expression levels did not appear as robust as in utero. Whereas neither profilaggrin/filaggrin nor loricrin were expressed in control explants cultured for 2 d, they were seen in explants treated with either thyroid hormone, glucocorticoids, or estrogens. In contrast, dihydrotestosterone treatment delayed the expression of profilaggrin/filaggrin and loricrin. Moreover, both clofibrate, a peroxisome proliferator-activated receptor-alpha ligand, and juvenile hormone III, a farnesoid X-activated receptor activator, markedly accelerated fetal epidermal differentiation, stimulating both profilaggrin/filaggrin and loricrin expression. Our results demonstrate that several hormones and activators of nuclear hormone receptors regulate epidermal differentiation during fetal development, affecting key constituents of both keratohyalin granules and the cornified envelope. Thus, a variety of ligands/activators of nuclear receptors accelerate not only permeability barrier ontogenesis, but also the expression of structural proteins essential for stratum corneum formation.

Glucocorticoid deficiency delays stratum corneum maturation in the fetal mouse

The stratum corneum (SC) matures during late gestation in man and other mammals. Using the fetal rat as an experimental model, we have previously shown that glucocorticoids given in pharmacologic doses accelerate fetal SC maturation and barrier formation. To determine whether glucocorticoids are required for normal SC maturation, we examined the epidermal morphology of glucocorticoid-deficient (C-) murine pups, derived from matings of mice homozygous for null mutations of the corticotropin-releasing hormone alleles. In control pups on day 17.5 of gestation (term is 19.5 d), a multilayered SC was present and neutral lipid deposition in a membrane pattern was observed using Nile red fluorescence histochemistry. Ultrastructurally, mature lamellar unit structures predominate in the SC intercellular domains. In contrast, in C-pups only a single layer of SC was evident on day 17.5, and secreted lamellar material was not organized into mature lamellar structures. Furthermore, the expression of structural proteins necessary for cornified envelope formation, involucrin, loricrin, and filaggrin, and the activity of the lipid synthetic enzymes beta-glucocerebrosidase and steroid sulfatase, markers of barrier maturation, were reduced in day 17.5 C-pups. C-pups derived from pregnancies supplemented with physiologic amounts of cortisone, however, display normal SC ultrastructure on day 17.5 of gestation. Furthermore, at birth, both control and C-pups exhibit a multilayered SC replete with mature lamellar membrane structures. These data demonstrate that fetal glucocorticoid deficiency delays SC maturation, and suggests that normal levels of glucocorticoids are not absolutely required for SC development.

Moles and melanoma

The melanoma epidemic in adults is well documented, and there is now evidence that the incidence of malignant melanoma in teenagers is increasing. Risk factors for melanoma are recognizable in children and include congenital nevi, numerous common nevi, and atypical nevi. Large congenital nevi overlying the head or spine also carry risk for central nervous system involvement, which, if symptomatic, carries a grave prognosis. Laser therapy has recently been advocated for small congenital nevi but often yields only temporary improvement. Adjuvant therapy with interferon alfa-2b holds promise for patients with metastatic melanoma. Melanoma risk is also linked to sun sensitivity and childhood exposures, and sunscreen use has been promoted for prevention of skin cancer. Because many sunscreens offer protection from ultraviolet (UV) B but not UVA, spectra that may be involved in melanoma induction, pediatricians should counsel their families to practice a full program of sun protection that includes sun avoidance and protective clothing and eyeware in addition to sunscreens.

Ontogeny of the epidermal permeability barrier

A competent permeability barrier must be present by the end of gestation to allow for life in a terrestrial environment. Indeed, early preterm infants display serious complications of skin immaturity. Yet, regardless of their degree of prematurity, all infants quickly develop a competent barrier. To learn more about the mechanisms and regulation of barrier ontogeny, we have utilized late-gestation fetal rodents. In 19-21 d fetal rats, we showed that barrier competence is accompanied by both enhanced epidermal development and formation of extracellular lamellar membranes in the stratum corneum. The identical sequence and time-course occurs when fetal rat skin is cultured in a serum-free medium. Glucocorticoids, thyroid hormone (T3), and estrogen accelerate, while androgens delay barrier formation both in utero and in the in vitro system, explaining the poorer outcome of premature males versus females. But neither T3 nor glucocorticoids are absolutely required for barrier development. Lifting fetal skin cultures to an air-medium interface also accelerates barrier formation, explaining the rapid emergence of barrier competence in very premature infants. PPARalpha and FXR activators, which, like T3, heterodimerize with the nuclear receptor, RXR, also accelerate barrier development in vitro. Finally, not only the nuclear receptor family, but also Ca++ could regulate key events late in barrier development.

Interactive MR imaging-guided biopsy and aspiration with a modified clinical C-arm system

OBJECTIVE

This investigation was performed to test the hypotheses that interactive guidance of MR image acquisition during needle-directed procedures using a clinical 0.2-T C-arm open MR imaging system integrated with a frameless optically linked stereotaxy system is feasible, and that procedure times can be sufficiently short to be well tolerated by the patient.

SUBJECTS AND METHODS

One hundred six MR-guided procedures were performed in 86 patients (ranging in age from 5 months to 88 years) using a clinical C-arm imaging system supplemented with an in-room RF-shielded liquid crystal display monitor, a frameless stereotaxy system, rapid gradient-echo sequences for needle guidance, and MR-compatible monitoring and surgical lighting equipment. We performed 50 biopsies and aspirations of the head and neck in 37 patients, 23 biopsies of musculoskeletal lesions in 22 patients, 16 biopsies of abdominal sites in 10 patients, six biopsies of the thoracolumbar spine or sacrum in six patients, and 11 shoulder joint injections for MR arthrography in 11 patients, in addition to 38 MR arthrographic injections on the same imaging system described in a previous report. Tissue sampling included fine-needle aspiration (n = 90) and cutting needle core biopsy (n = 41). Thirty-five patients underwent both procedures. Procedures were evaluated for success of needle placement, procedure time, and complications.

RESULTS

Needle placement was successful in all cases, and no complications occurred. Tissue was sufficient for pathologic diagnosis for all but eight patients. Passes per patient averaged 2.1. For fine-needle aspiration, instrument time averaged 7 min 42 sec per pass, cutting needle core biopsy averaged 6 min 24 sec, and shoulder injection averaged 8 min.

CONCLUSION

MR imaging guidance for needle procedures on a clinical 0.2-T C-arm system with supplemental interventional accessories is feasible, with relatively rapid needle placement.