Exploring Past to Present Shielding Guidelines.

PURPOSE: To explore the data and supporting evidence for the 2019 statement by the American Association of Physicists in Medicine (AAPM) that recommends limits to the routine use of fetal and gonadal shielding in medical imaging. METHODS: Three researchers searched 5 online databases, selecting articles from scholarly journals and radiology trade publications. Search results were filtered to include literature published from January 1, 2016, to August 9, 2022, to ensure relevance and provide historical background for the 2019 AAPM statement. RESULTS: The use of patient shielding during medical imaging did not reduce dose, and in certain instances, increased dose received by patients during computed tomography, fluoroscopy, or dental imaging. The use of shielding interfered with technology designed to reduce patient dose, including automatic exposure control and dose modulation. Research showed that errors in shield placement were common and that shields can act as sources of infection or carriers of harmful lead dust. DISCUSSION: In each article reviewed, a compelling case was made for discontinuing routine patient shielding during radiographic procedures. Serious opposition to the discontinuation of the shielding practice was not found. Opportunities exist for further study into technologists' and the public's understanding of the effects of radiation and technologists' compliance with new shielding policies. CONCLUSION: The challenges with properly using shielding, paired with recent technological advancements and a new understanding of radiation protection, have negated the need for contact shielding. This legacy practice can be discontinued in clinical settings, and educational materials for technologists and students should be updated to reflect these changes.

Barriers and Facilitators to Expanding Roles of Medical Assistants in Patient-Centered Medical Homes (PCMHs).

BACKGROUND: Many primary care practices participating in patient-centered medical home (PCMH) transformation initiatives are expanding the work roles of their medical assistants (MAs). Little is known about attitudes of MAs or barriers and facilitators to these role changes. METHODS: Secondary data analysis of qualitative cross-case comparison study of 15 New Jersey primary care practices participating in a PCMH project during 2012 to 2013. Observation field notes and in-depth and key informant interviews (with physicians, office managers, staff and care coordinators) were iteratively analyzed using grounded theory. RESULTS: MA roles and responsibilities changed from a mostly reactive role, completing tasks dependent on physician orders during the patient visit and facilitating patient flow through the office, to a more proactive one, conducting previsit planning, engaging in the overall care for patients, and assisting with population management. MAs differed in their attitudes about increased responsibilities, with some welcoming the opportunity to take on expanded roles, others resenting their increased responsibilities, and some expressing insufficient understanding regarding why new tasks and procedures were being implemented. Major barriers to MA role shifts included 1) insufficient understanding of the PCMH concept, 2) lack of time for added responsibilities, 3) additional workload without additional compensation, 4) disparate levels of medical knowledge and training, 5) reluctance of clinicians to delegate tasks, 6) uncertainty in making new workflow changes routine, 7) staff turnover, and 8) change fatigue. MAs were more positive about their role shifts when they 1) understood how their responsibilities fit within broader PCMH practice transformation goals; 2) received formal training in new tasks; 3) had detailed protocols and standing orders; 4) initiated role changes with small, achievable goals; 5) had open communication with clinicians and practice leaders; and 5) received additional compensation or paths to career advancement. CONCLUSIONS: Practice leaders need to be conscious of obstacles when they increase expectations of MAs, and they must be willing to invest time and resources into developing their MA workforce. An environment that allows open dialog with MAs and rewards and compensation that recognizes their increased efforts will help make expansion of MA roles occur more smoothly and efficiently.

Seasonal timing of sperm production in roe deer: interrelationship among changes in ejaculate parameters, morphology and function of testis and accessory glands.

Roe deer are seasonal breeders with a short rutting season from mid-July to mid-August. The seasonality of reproductive activity in males is associated with cyclic changes between growth and involution of both testes and the accessory sex glands. This study characterizes morphological and functional parameters of these organs prior to, during and after breeding season in live adult roe deer bucks. Size and morphology of the reproductive tract was monitored monthly by transcutaneous (testes, epididymis) and transrectal (accessory glands) ultrasonography. Semen was collected by electroejaculation. Concentration, motility and morphological integrity of spermatozoa as well as the content of proteins and testosterone in semen plasma were evaluated. Proportions of haploid, diploid and tetraploid cells were estimated by flow cytometry in testicular tissue biopsies. Serum testosterone was measured by enzyme immunoassay. Most parts of the male reproductive tract showed distinct circannual changes in size and texture. These changes were most pronounced in the testes, seminal vesicles, and prostate. All reproductive organs were highly developed during the rut only. The volume of ejaculates, total sperm number and percentages of motile and intact spermatozoa also showed a maximum during this period and corresponded with high proportions of haploid cells in the testis. The highest percentages of tetraploid cells were found in the prerutting period. The production of motile and intact spermatozoa correlated with both the protein content of semen plasma and the concentration of testosterone in semen plasma and blood serum. These results suggest the importance of combined actions of the testes and accessory sex glands and the crucial role of testosterone in facilitating the optimal timing of intensified semen production to ensure sufficient numbers of normal spermatozoa in seasonal breeders.

Administration of antiprogestin J956 for contraception in bears: a pharmacological study.

Effective and reversible control of reproduction in bears is highly desirable for conservation and management programs in zoos to establish genetically variable ex-situ populations of bears within the constraints of limited space in captivity. The reproductive physiology of bears is characterized by two main traits--seasonality and delayed implantation, which is progesterone dependent. This offers the opportunity to interrupt early pregnancy by short-term administration of antiprogestins. The aim of the present study was to investigate the pharmacological characteristics of antiprogestin J956 to establish an efficient contraceptive protocol for administration of J956 in captive bears. The J956 binds to the uterine progesterone receptor of bears (n = 2) with almost the same relative binding affinity (1.25) as progesterone. The blood serum level of J956 after oral (on four consecutive days) and single parenteral administration was determined by a modified progestin receptor assay. The relative bioavailability of J956 after oral administration was approximately 10% of the parenteral administration. The estimated half-life was 12 to 16 hours after oral administration. Parenteral treatment of J956 (10 mg/kg body mass) led to sustain plasma concentrations (6.4 +/- 1.3 ng/mL) in one black bear and in five brown bears. The plasma level lasted for almost 2 months. Oral and low dosage parenteral (1 mg/kg body mass) administration of J956 had no effect on ongoing pregnancies in bears. Whereas single parenteral administration with higher dosages of J956 (7.5 to 10 mg/kg body mass) efficiently prevented implantation of early embryos in eight female captive bears.

Control of reproduction with anti-progestin and oestrogens in captive bears.

The aim of this study was to establish new methods for controlling reproduction in bears. Anti-progestins were used to interrupt pregnancies. In two consecutive years, the anti-progestin J956 was administered to 11 female bears (nine Ursus arctos, one Ursus tibethanus, one Tremarctos ornatus) living in zoos. The anti-progestin J956 was given orally (n = 4) or parenterally (n = 12). The anti-progestin was administered alone or in combination with ethinyloestradiol, and before or after embryo implantation. The effects of anti-progestin treatment were determined using ultrasonographic examination of the urogenital tract and by monitoring progesterone concentrations in the blood and faeces. Oral administration of anti-progestin was not successful (successful in 0 of 4); however, in contrast, none of the parenteral treated animals remained pregnant (successful in 12 of 12). Parenteral treatment with J956, with or without ethinyloestradiol, was effective in disrupting pregnancy before implantation (successful in 6 of 6) and after implantation (successful in 6 of 6), but administration one month after implantation (n = 2) resulted in incomplete resorption of the fetuses. In conclusion, the administration of anti-progestins may be a useful method for preventing embryo implantation in captive bears.

Establishment of assisted reproduction technologies in female and male African wild dogs (Lycaon pictus).

Transrectal ultrasonography, electroejaculation and cryopreservation of spermatozoa were applied to the African wild dog (Lycaon pictus) to establish non-invasive protocols for assessing the reproductive health of one of the most endangered African canids. Transrectal ultrasonography was performed on immobilized male (n = 2) and female (n = 5) captive wild dogs. The testes and epididymides of the male dogs were imaged transcutaneously, followed by electrostimulation and cryopreservation of spermatozoa. The sonomorphology of the female and male urogenital tracts was characterized. In females, the vagina, cervix, non-pregnant uterus and ovary were imaged and the reproductive health of each female was evaluated. The sonographic assessment helped to identify one pyometra and extensive abdominal fat deposits in two other individuals in which pyometra had been suspected. Images of the adrenal glands showed differences in size among individuals of the same breeding group. Whether these differences were related to the dominance hierarchy remains to be determined. In males, visualization of the prostate gland, testis and epididymis indicated sexual maturity. Three ejaculatory fractions (1.0, 1.5 and 0.5 ml, with 50, 95 and 95% motility, respectively; 1.125 x 10(8) spermatozoa per ejaculate) were collected from one male. The motility of each of these fractions after thawing was 0, 30 and 40%, respectively. Electrostimulation of the second male, in which a cystic structure in a testis had been identified by sonography, resulted in an aspermic ejaculate (0.5 and 1.0 ml). These technologies provided basic data on reproduction in female and male African wild dogs and were an efficient way to evaluate reproductive health.