High-resolution MR of the intraparotid facial nerve and parotid duct.

PURPOSETo describe a high-resolution MR imaging technique that depicts the complex anatomy of the region of the parotid gland, focusing on the intraparotid components of the facial nerve and parotid duct.METHODSHigh-resolution T1-weighted images of the parotid gland were acquired with a prototype three-dimensional Fourier transform gradient-echo sequence that permits a very short echo time (4.2 milliseconds) by using a modified phase-encoded time-reduced acquisition scheme. The sequences were obtained at 1.5 T with a head and neck coil. Postprocessed multiplanar, curved and volumetric images were obtained. The most clinically useful images were acquired at parameters of 40/4.2 (TR/TEeff) a flip of 30 degrees, a field of view of 18 to 20 cm, a matrix of 512 x 288 or 512 x 256, an axial plane, 60 images, no gaps, and a section thickness of 1.5 mm. Eighteen healthy subjects were examined. The position of the facial nerve within the parotid gland was determined by identifying the facial nerve in the stylomastoid foramen and then following it on sequential sections through the parotid gland. Curved reformations were used to confirm the visibility of the nerve. A similar technique was used for the parotid duct.RESULTSThe image contrast obtained was similar to that of standard spin-echo T1-weighted images. The parotid gland showed intermediate signal intensity while the fat spaces showed high signal intensity. The vessels had variable signal intensity depending on saturation. The cerebrospinal fluid, nerves, muscles, and ducts had lower signal intensity. In all 18 subjects, the facial nerve from the brain stem to the parotid gland, and the parotid duct from the mouth to the hilus of the gland were seen bilaterally. The proximal intraparotid facial nerve to the level of the retromandibular vein was seen in 72% of the subjects and the main intraparotid ducts were seen in 66% of the subjects.CONCLUSIONHigh-resolution MR imaging offers simultaneous display of most of the important structures in the region of the parotid gland, including the intraparotid duct and facial nerve.     

Negative perceptions about self-control and identification with gender-role stereotypes related to binge eating, problem drinking, and to co-morbidity among adolescents.

PURPOSE: To examine the role of both positive and negative styles of self-control, and gender-role stereotypes in binge eating and problem drinking. METHOD: Participants were 428 adolescent boys and 555 girls from predominantly Anglo-Australian backgrounds who attended regional state schools in New South Wales, Australia. Students completed standardized questionnaires that assessed problem drinking, binge eating, self-control styles, and identification with gender-role stereotypes. ANOVA and post hoc Tukey tests were conducted to examine differences among adolescents who reported problems in binge eating, drinking, and both domains. RESULTS: Adolescents who reported eating and drinking problems also reported a high negative and a low positive sense of self-control coupled with self-identification with the traits that typically describe negative dimensions of gender-role stereotypes. Regardless of gender, problem drinking was mainly related to traits of negative masculinity (bossy, noisy aggressive, etc.) whereas binge eating was mainly related to negative femininity (shy, needs approval from others, etc.). Participants who reported eating and drinking symptoms recorded low scores on positive control, high scores on negative control, and also high scores on the negative dimensions of masculinity and femininity. SUMMARY: A negative and passive style of self-control coupled with an identification with negative dimensions of gender summarizes the type of self-regulation that is implicated in both binge eating and problem drinking, and co-morbid symptoms. There is a need for interventions working toward a more balanced gender self-concept and a positive sense of self-control.     

Immunization of Adolescents: Recommendations of the Advisory Committee on Immunization Practices, the Amerii Academy of Pediatrics, the American Academy of Family Physicians, and the American Medical Association

SUMMARY: This report concerning the immunization of adolescents (ie, persons 11–21 years of age, as defined by the American Medical Association [AMA] and the American Academy of Pediatrics [AAP]) is a supplement to previous publications (ie, MMWR 1994;43[No. RR-1] 1–38; the AAP 1994 Red Book: Report of the Committee on Infectious Diseases; Summary of Policy Recommendations for Periodic Health Examination, August 1996 from the American Academy of Family Physicians [AAFP]; and AMA Guidelines for Adolescent Preventive Services [GAPS]: Recommendations and Rationale). This report presents a new strategy to improve the delivery of vaccination services to adolescents and to integrate recommendations for vaccination with other preventive services provided to adolescents. This new strategy emphasizes vaccination of adolescents 11–12 years of age by establishing a routine visit to their health-care providers. Specifically, the purposes of this visit are to a) vaccinate adolescents who have not been previously vaccinated with varicella virus vaccine, hepatitis B vaccine, or the second dose of the measles, mumps, and rubella (MMR) vaccine; b) provide a booster dose of tetanus and diphtheria toxoids; c) administer other vaccines that may be recommended for certain adolescents; and d) provide other recommended preventive services. The recommendations for vaccination of adolescents are based on new or current information for each vaccine. The most recent recommendations from AC1P, AAP, AAFP, and AMA concerning specific vaccines and delivery of preventive services should be consulted for details.     

Retention of "safe" blood donors. The Retrovirus Epidemiology Donor Study

BACKGROUND: There are obvious advantages to increasing donor retention. However, for reasons of blood safety, certain donors may, in fact, be more desirable to retain than others. “Safe” donors are defined as those who provided a blood donation that was negative on all laboratory screening tests and who subsequently reported no behavioral risks in response to an anonymous survey. This study identifies the most important factors affecting the intention of “safe” donors to provide another donation. STUDY DESIGN AND METHODS: An anonymous survey asking about donation history, sexual history, injecting drug use, and recent donation experience was mailed to 50,162 randomly selected allogeneic donors (including directed donors) who gave blood from April through July or from October through December 1993 at one of the five United States blood centers participating in the Retrovirus Epidemiology Donor Study. Before mailing, questionnaires were coded to designate donors with nonreactive laboratory screening tests at their most recent donation. RESULTS: A total of 34,726 donors (69%) responded, with substantially higher response among repeat donors. According to reported intentions only, the vast majority of “safe” donors indicated a high likelihood of donating again within the next 12 months. Only 3.4 percent reported a low likelihood of donating again. A comparison of those likely to return and those unlikely to return reveals significant differences in demographics and in ratings of the donation experience. A higher proportion of those unlikely to return were first-time donors, minority-group donors, and donors with less education. The highest projected loss among “safe” donors was seen for those who gave a fair to poor assessment of their treatment by blood center staff or of their physical well-being during or after donating. CONCLUSION: These data suggest that efforts to improve donors' perceptions of their donation experience, as well as attention to the physical effects of blood donation, may aid in the retention of both repeat and first-time donors.     

Measurement of brain perfusion by volume-localized NMR spectroscopy using inversion of arterial water spins: accounting for transit time and cross-relaxation.

The theoretical model for perfusion measurement by NMR using arterial labeling of endogenous water is extended to include the effects of transit time and cross-relaxation of tissue water with macromolecules. Water magnetization in rat brain is monitored using the STEAM method to simultaneously determine the transit time, magnetization transfer rate constant, and perfusion. The results show that the transit time in rat brain is quite short, and thus its effect on perfusion measurement is small. It is also demonstrated both theoretically and experimentally that the steady-state effects of cross-relaxation with macromolecules on perfusion measurement are accounted for by a proper control experiment.