Improving coronary artery imaging in single source CT with cardiac motion correction using attention and spatial transformer based neural networks.

Motion artifact is a major challenge in cardiac CT which hampers accurate delineation of key anatomic (e.g. coronary lumen) and pathological features (e.g. stenosis). Conventional motion correction techniques are limited on patients with high / irregular heart rate, due to simplified modeling of CT systems and cardiac motion. Emerging deep learning based cardiac motion correction techniques have demonstrated the potential of further quality improvement. Yet, many methods require CT projection data or advanced motion simulation tools that are not readily available. We aim to develop an image-domain motion-correction method, using convolutional neural network (CNN) integrated with customized attention and spatial transformer techniques. Forty cardiac CT exams acquired from a clinical dual-source CT system were retrospectively collected to generate training (n=26) and testing (n=14) sets. Dual-source data uniquely allow image reconstruction with different temporal resolutions from the same patient scan. Slow temporal resolution (140ms; equivalent to single-source CT (SSCT) half scan) and fast temporal resolution (75ms; dual source) images were reconstructed to generate paired samples of motion-corrupted and reference images. The combinations of 2 training-inference strategies and 3 CNNs were evaluated: strategy #1 - whole-heart images in training / inference; strategy #2 - vessel patches in training / inference; CNN #1 - attention only; CNN #2 - spatial-transformer (STN) only; CNN #3 - attention & STN synergy. Testing data showed that CNN #3 with strategy #2 provided relatively better performance: improving vessel delineation, increasing structural similarity index from 0.85 to 0.91, and reducing mean CT number error of lumen by 71.0%. Our method could improve the image quality in cardiac exams with SSCT.

The impact of COVID-19 on oncology professionals-one year on: lessons learned from the ESMO Resilience Task Force survey series.

BACKGROUND: COVID-19 has had a significant impact on the well-being and job performance of oncology professionals globally. The European Society for Medical Oncology (ESMO) Resilience Task Force collaboration set out to investigate and monitor well-being since COVID-19 in relation to work, lifestyle and support factors in oncology professionals 1 year on since the start of the pandemic. METHODS: An online, anonymous survey was conducted in February/March 2021 (Survey III). Key outcome variables included risk of poor well-being or distress (expanded Well-Being Index), feeling burnout (single item from expanded Well-Being Index), and job performance since COVID-19. Longitudinal analysis of responses to the series of three surveys since COVID-19 was carried out, and responses to job demands and resources questions were interrogated. SPSS V.26.0/V.27.0 and GraphPad Prism V9.0 were used for statistical analyses. RESULTS: Responses from 1269 participants from 104 countries were analysed in Survey III: 55% (n = 699/1269) female, 54% (n = 686/1269) >40 years, and 69% (n = 852/1230) of white ethnicity. There continues to be an increased risk of poor well-being or distress (n = 464/1169, 40%) and feeling burnout (n = 660/1169, 57%) compared with Survey I (25% and 38% respectively, P < 0.0001), despite improved job performance. Compared with the initial period of the pandemic, more participants report feeling overwhelmed with workload (45% versus 29%, P < 0.0001). There remain concerns about the negative impact of the pandemic on career development/training (43%), job security (37%). and international fellowship opportunities (76%). Alarmingly, 25% (n = 266/1086) are considering changing their future career with 38% (n = 100/266) contemplating leaving the profession. CONCLUSION: Oncology professionals continue to face increased job demands. There is now significant concern regarding potential attrition in the oncology workforce. National and international stakeholders must act immediately and work closely with oncology professionals to draw up future-proof recovery plans.

The concerns of oncology professionals during the COVID-19 pandemic: results from the ESMO Resilience Task Force survey II.

BACKGROUND: The COVID-19 pandemic has resulted in significant changes to professional and personal lives of oncology professionals globally. The European Society for Medical Oncology (ESMO) Resilience Task Force collaboration aimed to provide contemporaneous reports on the impact of COVID-19 on the lived experiences and well-being in oncology. METHODS: This online anonymous survey (July-August 2020) is the second of a series of global surveys launched during the course of the pandemic. Longitudinal key outcome measures including well-being/distress (expanded Well-being Index-9 items), burnout (1 item from expanded Well-being Index), and job performance since COVID-19 were tracked. RESULTS: A total of 942 participants from 99 countries were included for final analysis: 58% (n = 544) from Europe, 52% (n = 485) female, 43% (n = 409) ≤40 years old, and 36% (n = 343) of non-white ethnicity. In July/August 2020, 60% (n = 525) continued to report a change in professional duties compared with the pre-COVID-19 era. The proportion of participants at risk of poor well-being (33%, n = 310) and who reported feeling burnout (49%, n = 460) had increased significantly compared with April/May 2020 (25% and 38%, respectively; P < 0.001), despite improved job performance since COVID-19 (34% versus 51%; P < 0.001). Of those who had been tested for COVID-19, 8% (n = 39/484) tested positive; 18% (n = 7/39) felt they had not been given adequate time to recover before return to work. Since the pandemic, 39% (n = 353/908) had expressed concerns that COVID-19 would have a negative impact on their career development or training and 40% (n = 366/917) felt that their job security had been compromised. More than two-thirds (n = 608/879) revealed that COVID-19 has changed their outlook on their work-personal life balance. CONCLUSION: The COVID-19 pandemic continues to impact the well-being of oncology professionals globally, with significantly more in distress and feeling burnout compared with the first wave. Collective efforts from both national and international communities addressing support and coping strategies will be crucial as we recover from the COVID-19 crisis. In particular, an action plan should also be devised to tackle concerns raised regarding the negative impact of COVID-19 on career development, training, and job security.

The impact of COVID-19 on oncology professionals: results of the ESMO Resilience Task Force survey collaboration.

BACKGROUND: The impact of the coronavirus disease 2019 (COVID-19) pandemic on well-being has the potential for serious negative consequences on work, home life, and patient care. The European Society for Medical Oncology (ESMO) Resilience Task Force collaboration set out to investigate well-being in oncology over time since COVID-19. METHODS: Two online anonymous surveys were conducted (survey I: April/May 2020; survey II: July/August 2020). Statistical analyses were performed to examine group differences, associations, and predictors of key outcomes: (i) well-being/distress [expanded Well-being Index (eWBI; 9 items)]; (ii) burnout (1 item from eWBI); (iii) job performance since COVID-19 (JP-CV; 2 items). RESULTS: Responses from survey I (1520 participants from 101 countries) indicate that COVID-19 is impacting oncology professionals; in particular, 25% of participants indicated being at risk of distress (poor well-being, eWBI ≥ 4), 38% reported feeling burnout, and 66% reported not being able to perform their job compared with the pre-COVID-19 period. Higher JP-CV was associated with better well-being and not feeling burnout (P < 0.01). Differences were seen in well-being and JP-CV between countries (P < 0.001) and were related to country COVID-19 crude mortality rate (P < 0.05). Consistent predictors of well-being, burnout, and JP-CV were psychological resilience and changes to work hours. In survey II, among 272 participants who completed both surveys, while JP-CV improved (38% versus 54%, P < 0.001), eWBI scores ≥4 and burnout rates were significantly higher compared with survey I (22% versus 31%, P = 0.01; and 35% versus 49%, P = 0.001, respectively), suggesting well-being and burnout have worsened over a 3-month period during the COVID-19 pandemic. CONCLUSION: In the first and largest global survey series, COVID-19 is impacting well-being and job performance of oncology professionals. JP-CV has improved but risk of distress and burnout has increased over time. Urgent measures to address well-being and improve resilience are essential.

Validation of a Brucella abortus competitive enzyme-linked immunosorbent assay for use in Rocky Mountain elk (Cervus elaphus nelsoni).

Brucellosis caused by infection with Brucella abortus is present in some elk (Cervus elaphus nelsoni) of the Greater Yellowstone Area (parts of Wyoming, Montana, and Idaho, USA). Since 1985, the Wyoming Game and Fish Department has vaccinated elk on elk feedgrounds in northwestern Wyoming during the winter months using B. abortus strain 19 (strain 19). Analysis of this vaccination program is hampered by the inability of standard serologic tests to differentiate between strain 19 vaccinated elk and those exposed to field strain B. abortus. In 1993, a competitive enzyme-linked immunosorbent assay (cELISA) was licensed to serologically differentiate between strain 19 vaccinated cattle and cattle exposed to field strain B. abortus. Seven groups of elk sera representing various B. abortus exposure histories were used to validate the cELISA test for elk. The cELISA test differentiated strain 19 vaccinated elk from elk that were challenged with B. abortus strain 2308, a pathogenic laboratory strain. The specificity of the cELISA was 96.8% for elk vaccinated with strain 19 only and sampled between 6 mo and 2 yr post vaccination, or with no B. abortus exposure. The sensitivity of the cELISA was 100%. The cELISA test will be useful in evaluating sera collected from elk in vaccinated, brucellosis endemic herds in the Greater Yellowstone Area.

Brucella abortus strain RB51 vaccination in elk. I. Efficacy of reduced dosage.

Bovine brucellosis is a serious zoonotic disease affecting some populations of Rocky Mountain elk (Cervus elaphus nelsoni) and bison (Bison bison) in the Greater Yellowstone Area, USA. The fear that elk and/or bison may spread Brucella abortus to livestock has prompted efforts to reduce or eliminate the disease in wildlife. Brucella abortus strain RB51 (RB51) vaccine has recently been approved for use in cattle. Unlike strain 19 vaccine, RB51 does not cause false positive reactions on standard brucellosis serologic tests. If effective, it may become the vaccine of choice for wildlife. In February 1995, 45 serologically negative female elk calves were trapped and taken to the Sybille Wildlife Research and Conservation Education Unit near Wheatland, Wyoming, USA. In May 1995, 16 of these elk calves were hand-vaccinated with 1 x 10(9) colony forming units (CFU) of RB51, 16 were vaccinated with 1 x 10(8) CFU RB51 by biobullet, and 13 were given a saline placebo. The elk were bred in fall of 1996 and they were challenged with 1 x 10(7) CFU of B. abortus strain 2308 by intraconjunctival inoculation in March 1997. Thirteen (100%) control elk aborted, 14 (88%) hand-vaccinated elk aborted, and 12 (75%) biobullet vaccinated elk aborted or produced nonviable calves. These results suggest that a single dose of 1 x 10(8) to 1 x 10(9) CFU RB51 does not provide significant protection against B. abortus induced abortion in elk. However, the vaccine appears to be safe at this dose and additional study may reveal a more effective RB51 vaccine regimen for elk.

Safety of Brucella abortus strain RB51 in deer mice.

Brucella abortus strain RB51 is an approved brucellosis vaccine for use in cattle that may have potential as an oral vaccine for use in elk (Cervus elaphus) and/or bison (Bison bison). This study was designed to determine effects of strain RB51 on deer mice (Peromyscus maniculatus), a nontarget species that could have access to treated baits in a field situation. In February 1994, 90 mice were orally dosed or intraperitoneally injected with 1 x 10(8) colony forming units strain RB51 and 77 controls were similarly dosed with sterile saline. At weekly intervals through early April 1994, 4 to 6 mice from each group were euthanized, gross necropsies performed, spleens and uteruses cultured, and tissues examined histologically. All orally inoculated mice cleared the infection by 6 wk post-inoculation (PI). While most of the injected mice cleared the infection by 7 wk PI, a few required 9 wk. There were minimal adverse effects attributable to strain RB51. Apparently, strain RB51 would not negatively impact P. maniculatus populations if it were used in a field situation. Also, deer mice appear to be able to clear the vaccine in 6 to 9 wk, thus the probability of these mice transmitting the vaccine to other animals is low.

Modification of expansin transcript levels in the maize primary root at low water potentials.

We previously demonstrated that maintenance of cell elongation in the apical region of maize primary roots at low water potentials (psi(w)) was associated with an increase in expansin activity and extractable expansin protein. Here, we characterized the spatial pattern of expansin gene expression along the growing maize root and studied the effect of low psi(w) on expansin gene expression. Roots were divided into three segments: apical 0 to 5 mm, subapical 5 to 10 mm, and non-growing 10 to 20 mm. Of the five expansin genes expressed in control roots, two alpha-expansins (Exp1 and Exp5) and two beta-expansins (ExpB2 and ExpB8) are expressed specifically in the growing region, whereas expression of beta-expansin ExpB6 is shifted basipetally. After seedlings were transplanted to vermiculite with a psi(w) of -1.6 MPa, transcripts for Exp1, Exp5, and ExpB8 rapidly accumulated in the apical region of the root. These mRNA changes correlated with the maintenance of root elongation and increases in wall extensibility found previously. The beta-expansins ExpB2 and ExpB6 showed distinctive patterns of expression and responses to low psi(w,) indicative of distinctive functions. Inhibition of abscisic acid (ABA) accumulation at low psi(w) (by fluridone treatment) had no effect on expansin expression, except that ExpB2 transcript level showed a minor dependence on ABA. Gene-specific regulation of alpha- and beta-expansin mRNA pools likely contributes to growth alterations of the maize (Zea mays) root as it adapts to a low psi(w), but these changes do not appear to be mediated by changes in ABA content.

Epizootiology of chronic wasting disease in free-ranging cervids in Colorado and Wyoming.

Surveillance and epidemic modeling were used to study chronic wasting disease (CWD), a transmissible spongiform encephalopathy that occurs naturally among sympatric, free-ranging deer (Odocoileus spp.) and Rocky Mountain elk (Cervus elaphus nelsoni) populations in contiguous portions of northeastern Colorado and southeastern Wyoming (USA). We used clinical case submissions to identify endemic areas, then used immunohistochemistry to detect CWD-infected individuals among 5,513 deer and elk sampled via geographically-focused random surveys. Estimated overall prevalence (prevalence, 95% confidence interval) in mule deer (4.9%, 4.1 to 5.7%) was higher than in white-tailed deer (2.1%, 0.5 to 3.4%) or elk (0.5%, 0.001 to 1%) in endemic areas; CWD was not detected in outlying portions of either state. Within species, CWD prevalence varied widely among biologically- or geographically-segregated subpopulations within the 38,137 km2 endemic area but appeared stable over a 3-yr period. The number of clinical CWD cases submitted from an area was a poor predictor of local CWD prevalence, and prevalence was typically > or =1% before clinical cases were first detected in most areas. Under plausible transmission assumptions that mimicked field data, prevalence in epidemic models reached about 1% in 15 to 20 yr and about 15% in 37 to 50 yr. Models forecast population declines once prevalence exceeded about 5%. Both field and model data supported the importance of lateral transmission in CWD dynamics. Based on prevalence, spatial distribution, and modeling, we suggest CWD has been occurring in northeastern Colorado and southeastern Wyoming for >30 yr, and may be best represented as an epizootic with a protracted time-scale.

Endogenous ABA maintains shoot growth in tomato independently of effects on plant water balance: evidence for an interaction with ethylene.

To examine whether the reduced shoot growth of abscisic acid (ABA)-deficient mutants of tomato is independent of effects on plant water balance, flacca and notabilis were grown under controlled-humidity conditions so that their leaf water potentials were equal to or higher than those of well-watered wild-type plants throughout development. Most parameters of shoot growth remained markedly impaired and root growth was also greatly reduced. Additional experiments with flacca showed that shoot growth substantially recovered when wild-type levels of ABA were restored by treatment with exogenous ABA, even though improvement in leaf water potential was prevented. The ability of applied ABA to increase growth was greatest for leaf expansion, which was restored by 75%. The ethylene evolution rate of growing leaves was doubled in flacca compared to the wild type and treatment with silver thiosulphate to inhibit ethylene action partially restored shoot growth. The results demonstrate that normal levels of endogenous ABA are required to maintain shoot development, particularly leaf expansion, in well-watered tomato plants, independently of effects on plant water balance. The impairment of shoot growth caused by ABA deficiency is at least partly attributable to ethylene.

Safety of Brucella abortus strain RB51 in bull elk.

Some of the elk (Cervus elaphus nelsoni) of the Greater Yellowstone Area (Wyoming, Idaho, Montana; USA) are infected with Brucella abortus, the bacterium that causes bovine brucellosis. Brucella abortus strain RB51 vaccine is being considered as a means to control B. abortus induced abortions in cow elk. However, the most probable vaccination strategies for use in free-ranging elk might also result in some bull elk being inoculated, thus, it is important to insure that the vaccine is safe in these animals. In the winter of 1995, 10 free-ranging bull elk calves were captured, tested for B. abortus antibodies, and intramuscularly inoculated with 1.0 x 10(9) colony forming units (CFU) of B. abortus strain RB51. Blood was collected for hemoculture and serology every 2 wk after inoculation for 14 wk. Beginning 4 mo postinoculation and continuing until 10 mo postinoculation elk were serially euthanized, necropsied, and tissues collected for culture and histopathology. These elk cleared the organism from the blood within 6 wk and from all tissues within 10 mo. No lesions attributable to B. abortus were found grossly and only minimal to mild lymphoplasmacytic epididymitis was found in a few elk on histologic examination. In a separate study, six adult bull elk from Wind Cave National Park (South Dakota, USA) were taken to a ranch near Carrington (North Dakota, USA). Three were orally inoculated with approximately 1.0 x 10(10) CFU of RB51 and three were inoculated with corn syrup and saline. Ninety days post-inoculation semen was examined and cultured from these bulls. Strain RB51 was not cultured from their semen at that time. There were no palpable abnormalities in the genital tract and all elk produced viable sperm. Although they contain small sample sizes, these studies suggest that B. abortus strain RB51 is safe in bull elk.

Causes of mortality of the Wyoming toad.

Wyoming toads (Bufo baxteri) that died from January 1989 to June 1996 were submitted to the Wyoming State Veterinary Laboratory (Laramie, Wyoming, USA) for postmortem evaluation. These consisted of 108 free-ranging toads and 170 animals from six captive populations. Ninety-seven (90%) of 108 free-ranging toad carcasses were submitted during September and October. From 1989 to 1992, 27 (77%) of 35 mortalities in the captive populations occurred in October, November, and December. From 1993 to 1996, mortality in captive toads occurred without a seasonal pattern and coincided with changes in hibernation protocols that no longer mimicked natural cycles. Cause of mortality was determined in 147 (53%) of the 278 cases. Mycotic dermatitis with secondary bacterial septicemia was the most frequent diagnosis in 104 (71%) of 147 toads. Basidiobolus ranarum was found by microscopic examination of skin sections in 100 (96%) of 104 of these mortalities. This fungus was isolated from 30 (56%) of 54 free-ranging and 24 (48%) of 50 captive toads. This research documents the causes of mortality for both free-ranging and captive endangered Wyoming toads over a 7 yr period.

Letters.

HYDROGELS AND FOAM DRESSINGS IN COMBINATION CONTROLLING BLEEDING IN FUNGATING WOUNDS HYDROSTATIC LEG ULCERS COMMUNITY LEG ULCER CLINICS.

Histologic evaluation of the long term effects of tretinoin on photodamaged skin.

Sustained improvement with prolonged topical tretinoin for photodamaged skin has been well documented for up to 22 months of continuous treatment. We now report long-term (4 years) histologic effects of topical tretinoin in photodamaged skin of 27 patients, the longest study to date. The observed decreases in dermal elastin content and perivascular inflammation and increase in epidermal mucin in facial biopsies obtained after up to 4 years of treatment may be partly responsible for the continued clinical improvement. Furthermore, the study shows that there are no untoward effects on keratinocytes or melanocytes during long-term use of topical tretinoin.

Infectious and parasitic diseases of captive carnivores, with special emphasis on the black-footed ferret (Mustela nigripes).

Captive carnivores are susceptible to a wide array of infectious and parasitic diseases, which reflects the diversity of the seven families of Carnivora. Unfortunately, relatively few in-depth studies have been conducted on diseases of non-domestic carnivores, and much remains to be learned, especially regarding diseases of small carnivores (e.g. mustelids, viverrids and procyonids). The more important infectious diseases of carnivores include rabies, canine distemper, and diseases caused by parvoviruses, coronaviruses and herpesviruses. Few parasitic or bacterial pathogens are significant in captive populations, and appropriate husbandry, therapy, vaccines and quarantine minimize the risk of disease. Extrapolations from one species to another regarding disease susceptibility may be incorrect. The black-footed ferret (Mustela nigripes) serves as an example of a carnivore significantly affected by infectious diseases, some of which were expected while others could not have been predicted from generalized knowledge of diseases of mustelids. This highlights the need to understand the natural history of each species maintained in captivity.

Plague in a black-footed ferret (Mustela nigripes).

Diagnosis of sylvatic plague in a captive black-footed ferret (Mustela nigripes) was based on gross and microscopic lesions, fluorescent antibody tests, culture of Yersinia pestis, and immunohistochemistry. Gross lesions consisted of acute hemorrhage and necrosis associated with cervical and mesenteric lymph nodes, subcutaneous hemorrhages, and pulmonary edema. Acute edema, hemorrhage, and necrosis with numerous bacteria in blood vessels and sinusoids characterized microscopic lesions. Occurrence of fatal plague in a black-footed ferret potentially has significant implications for recovery of this endangered species due to the widespread distribution of plague in prairie dog colonies throughout historic black-footed ferret range.

Brucellosis in free-ranging bison (Bison bison) from Teton County, Wyoming.

Brucellosis was studied opportunistically in bison (Bison bison) in the free-ranging Jackson herd of approximately 120 in Teton County, Wyoming (USA) in March 1989. Recent abortion was diagnosed in a 2-yr-old cow and Brucella abortus biovar 1 was isolated from vaginal discharge, uterine contents, uterus, and supramammary lymph nodes. Endometritis was characterized by lymphoplasmacytic infiltrates in the lamina propria and neutrophils in uterine glands and within necrotic debris and exudate in the uterine lumen. A 5-yr-old bull had diffuse lymphoplasmacytic infiltrates in epididymis and accessory sex glands; B. abortus was isolated from seminal vesicle and ampulla. Twenty-seven (77%) of 35 bison tested from 1989 to 1990 were serologically positive or suspect on tests for Brucella antibodies. We report the occurrence of abortion due to brucellosis in free-ranging bison in the Jackson herd, suggest that bison in this herd are capable of transmitting brucellosis to other susceptible hosts, and report the first confirmation of brucellosis in this herd.

An ultrastructural study of the effects of topical tretinoin on microcomedones.

It has been hypothesized that topical tretinoin prevents inflammatory acne lesions by loosening follicular impactions (microcomedones) and clearing the follicular canal of retained keratin. To lend support to this hypothesis, 15 volunteers applied 0.1% tretinoin cream once daily for 12 weeks to one side of the face and an emollient cream to the other side. During the 12-week treatment period, samples of microcomedones were obtained using the follicular biopsy technique. By 6 weeks, the number of microcomedones was reduced approximately 50% from baseline on the side treated with tretinoin and approximately 80% at the end of the study. Only a minimal reduction in the number of microcomedones was seen on the emollient side, even after 12 weeks of application. Morphologic examination showed a progressive loss of the cohesiveness of the microcomedones and ultrastructural alterations in the epithelial cells treated with tretinoin. The microcomedones changed from well-developed keratinous plugs containing many bacteria to a few wispy layers of keratin containing few bacteria. This study confirms the microcomedolytic activity of tretinoin and provides evidence that this activity is associated with changes in the differentiation of the follicular epithelial cells.