A national UK audit for diagnostic accuracy of preoperative CT chest in emergency and elective surgery during COVID-19 pandemic

AIM

To report on a snap audit of all departments in the UK as to the value of preoperative thoracic imaging, preferably computed tomography (CT), of patients undergoing any surgery to assess for changes consistent with COVID-19 preoperatively.

MATERIALS AND METHODS

All Imaging departments in the UK were contacted and asked to record the number of preoperative CT examinations performed in patients being considered for both emergency and elective surgical intervention over a 5-day period in May 2020.

RESULTS

Forty-seven percent of departments replied with data provided on >820 patients. Nineteen percent of additional preoperative CT was in patients undergoing elective intervention and 81% in patients presenting with surgical abdominal pain. There was a high rate of false positives in patients who tested negative for COVID-19, producing a sensitivity for thoracic CT of 68.4%.

CONCLUSION

This UK-wide audit demonstrates that a large number of additional thoracic imaging examinations over a 5-day period were performed with a low sensitivity for the identification of COVID-19 in this preoperative group of patients. Given these findings, it is difficult to justify this additional examination in this group of patients.

Environmental shedding of toxigenic Clostridioides difficile by asymptomatic carriers: A prospective observational study

OBJECTIVES

The aim was to compare the burden of environmental shedding of toxigenic Clostridioides difficile among asymptomatic carriers, C. difficile-infected (CDI) patients and non-carriers in an inpatient non-epidemic setting.

METHODS

C. difficile carriage was determined by positive toxin-B PCR from rectal swabs of asymptomatic patients. Active CDI was defined as a positive two-step enzyme immunoassay/polymerase chain reaction (EIA/PCR) test in patients with more than three unformed stools/24 hr. C. difficile environmental contamination was assessed by obtaining specimens from ten sites in the patients' rooms. Toxigenic strains were identified by PCR. We created a contamination scale to define the overall level of room contamination that ranged from clean to heavy contamination.

RESULTS

One hundred and seventeen rooms were screened: 70 rooms inhabited by C. difficile carriers, 30 rooms by active CDI patients and 17 rooms by non C. difficile -carriers (control). In the carrier rooms 29 (41%) had more than residual contamination, from which 17 (24%) were heavily contaminated. In the CDI rooms 12 (40%) had more than residual contamination from which three (10%) were heavily contaminated, while in the control rooms, one room (6%) had more than residual contamination and none were heavily contaminated. In a multivariate analysis, the contamination score of rooms inhabited by carriers did not differ from rooms of CDI patients, yet both were significantly more contaminated than those of non-carriers odd ratio 12.23 and 11.16 (95% confidence interval 1.5-99.96 p 0.0195, and 1.19-104.49 p 0.035), respectively.

DISCUSSION

Here we show that the rooms of C. difficile carriers are as contaminated as those of patients with active CDI and significantly more than those of non-carriers.

Time spent looking at food during a delay of gratification task is positively associated with children's consumption at ad libitum laboratory meals

Greater ability to delay gratification for an immediate food reward may protect against the development of obesity. However, it is not known if the behaviors children exhibit during a delay of gratification task are related to overeating in other contexts. The purpose of this analysis was to assess the relationship between observed child coping strategies during a delay of gratification task and laboratory intake from ad libitum test-meals. The sample consisted of 40, 7-9 year old children (40% (N = 16 with overweight/obesity). Across 5 laboratory visits, children consumed 3 identical test-meals presented after varying exposure conditions (i.e., no exposure, exposure to food commercials, exposure to toy commercials). On the first visit, children were recorded during a delay of gratification task which was coded for three behavioral themes: looking at vs. away from food, talking vs. staying silent, and fidgeting vs. sitting still. Pearson correlations and multiple regressions were run to look at the relationships between coping strategies and test-meal intake. Time spent looking away from food was negatively associated with ad libitum food consumption at the meals. Conversely, greater time spent looking at food was positively associated with ad libitum food consumption. These relationships were independent of covariates likely to influence intake (e.g., sex, age, weight status, parent income) and were more robust following food rather than toy commercial exposure. Children who spent more time looking at food and less time looking away during a delay of gratification task may be vulnerable to overeating in other contexts. Upon replication in larger samples, these behaviors could serve as modifiable targets in the development of childhood obesity prevention programs.

Molecular epidemiology of community-onset methicillin-resistant Staphylococcus aureus infections in Israel

Data on community-associated (CA) methicillin-resistant Staphylococcus aureus (MRSA) in Israel are scarce. The objective of this study was to characterize the major CA-MRSA clones in Israel. All clinical MRSA isolates detected in the community during a period of 2.5 years (2011-2013) from individuals insured by a major health maintenance organization in Israel were collected, with additional data from medical records. Antibiotic susceptibility patterns and staphylococcal chromosomal cassette mec (SCCmec) typing were determined. SCCmec IV and V isolates were further typed by pulsed-field gel electrophoresis (PFGE), spa typing, and detection of a panel of toxin genes. MRSA were detected in 280 patients, mostly from skin infections. Patients with SCCmec IV (n = 120, 43 %) were younger (p < 0.0001) and reported less contact with healthcare facilities. Almost all isolates were trimethoprim-sulfamethoxazole susceptible (98 %). spa-CC032, a typical nosocomial MRSA clone, accounted for 28 % of SCCmec IV. The two major CA-MRSA clones were t008 USA300 (13 %) and t991 (10 %); t991 was isolated mainly from children (75 %), was Panton-Valentine leukocidin (PVL) negative but eta-positive, and was typically susceptible to most antibiotic groups. PVL-positive strains (n = 31) included mainly USA300 (52 %) and t019 (13 %). While multiple genetic lineages were evident among community-onset MRSA in Israel, approximately 20 % are typical CA-MRSA clones, mainly USA300 and a local clone, t991.

The radiosensitizing effect of the aurora kinase inhibitors, ENMD-2076, on canine mast cell tumours in vitro

ENMD-2076 is an aurora kinase inhibitor that also has multi-target tyrosine kinase inhibitor properties. In this study, the mRNA and the protein expression of aurora-A and aurora-B were evaluated in three canine mast cell tumour cell lines. Dose-dependent cytotoxicity was seen in the cells treated, and it affected the cell cycle with cells in the G2/M phase being selectively killed. The cells were also evaluated for radiosensitivity with/without ENMD-2076, and radiosensitization was seen after 3 Gy and 6 Gy exposures with ENMD-2076 for 48 h. Protein expression of caspase-3 was gradually increased, and the expression intensity was highest at 24 h post irradiation in cells without ENMD-2076 treatment, which indicates that radiation exposure with ENMD-2076-induced cell death faster than radiation treatment alone. Our study results suggest the potential usefulness of treating canine mast cell tumours with aurora kinase inhibitors alone or in conjunction with radiation therapy.

Association between pubertal development and depressive symptoms in girls from a UK cohort

BACKGROUND

It is unclear whether pubertal status or timing of puberty explains the increase in depressive symptoms in girls during adolescence.

METHOD

This is a longitudinal study based on 2506 girls from the Avon Longitudinal Study of Parents and Children (ALSPAC). Self-reported depressive symptoms at 10.5, 13 and 14 years were assessed using the Short Mood and Feelings Questionnaire (SMFQ). Pubertal status (Tanner breast and pubic hair stage) and timing of menarche were derived from questionnaires administered from age 8 to 14 years. We used multivariable regression models to examine the relative contributions of pubertal status and timing in accounting for increases in level of depressive symptoms at 14 years.

RESULTS

With increasing age, the association between breast development and depressive symptoms strengthened. Pubertal status (breast stage), rather than timing of menarche, was independently associated with depressive symptoms at 14 years. There was strong evidence for a linear relationship between breast stage and depressive symptoms at 14 years [increase in 0.17 S.D. (range 0.10-0.24) of depressive symptoms for advancement of each breast stage].

CONCLUSIONS

Depressive symptoms in mid-adolescence were more strongly influenced by breast stage than timing of menarche. This could imply that the female rise in depression during adolescence is due to increasing estrogen levels, and might explain why the gender difference in rates of depression emerges at this stage. Future research should be aimed at identifying the mechanism of action of pubertal change, including direct effects of pubertal hormones and indirect effects mediated by psychosocial factors.

Onset of sexual maturity in female chickens is genetically linked to loci associated with fecundity and a sexual ornament

Onset of sexual maturation is a trait of extreme importance both evolutionarily and economically. Unsurprisingly therefore, domestication has acted to reduce the time to sexual maturation in a variety of animals, including the chicken. In comparison with wild progenitor chickens [the Red Junglefowl (RJF)], domestic layer hens attain maturity approximately 20% earlier. In addition, domestic layers also possess larger combs (a sexual ornament), produce more eggs and have denser bones. A large quantitative trait loci (QTL) analysis (n=377) was performed using an F(2) intercross between a White Leghorn layer breed and a RJF population, with onset of sexual maturity measured and mapped to three separate loci. This cross has already been analysed for comb mass, egg production and bone allocation. Onset of sexual maturity significantly correlated with comb mass, whilst the genetic architecture for sexual maturity and comb mass overlapped at all three loci. For two of these loci, the QTL for sexual maturity and comb mass were statistically indistinguishable from pleiotropy, suggesting that the alleles that increase comb mass also decrease onset of sexual maturity.

Dynamic skeletal muscle stimulation and its potential in bone adaptation

To identify mechanotransductive signals for combating musculoskeletal deterioration, it is essential to determine the components and mechanisms critical to the anabolic processes of musculoskeletal tissues. It is hypothesized that the interaction between bone and muscle may depend on fluid exchange in these tissues by mechanical loading. It has been shown that intramedullary pressure (ImP) and low-level bone strain induced by muscle stimulation (MS) has the potential to mitigate bone loss induced by disuse osteopenia. Optimized MS signals, i.e., low-intensity and high frequency, may be critical in maintaining bone mass and mitigating muscle atrophy. The objectives for this review are to discuss the potential for MS to induce ImP and strains on bone, to regulate bone adaptation, and to identify optimized stimulation frequency in the loading regimen. The potential for MS to regulate blood and fluid flow will also be discussed. The results suggest that oscillatory MS regulates fluid dynamics with minimal mechanical strain in bone. The response was shown to be dependent on loading frequency, serving as a critical mediator in mitigating bone loss. A specific regimen of dynamic MS may be optimized in vivo to attenuate disuse osteopenia and serve as a biomechanical intervention in the clinical setting.

Regulation of mechanical signals in bone

OBJECTIVES

Response of the skeleton to application and removal of specific mechanical signals is discussed. Anabolic effects of high-frequency, low-magnitude vibrations, a mechanical intervention with a favorable safety profile, as well as the modulation of bone loss by genetic and epigenetic factors during disuse are highlighted.

METHODS

Review.

RESULTS

Bone responds to a great variety of mechanical signals and both high- and low-magnitude stimuli can be sensed by the skeleton. The ability of physical signals to influence bone morphology is strongly dependent on the signal's magnitude, frequency, and duration. Loading protocols at high signal frequencies (vibrations) allow a dramatic reduction in the magnitude of the signal. In the axial skeleton, these signals can be anabolic and anti-catabolic and increase the structural strength of the tissue. They further have shown potential in maxillofacial applications to accelerate the regeneration of bone within defects. Bone's sensitivity to the application and removal of mechanical signals is heavily under the control of the genome. Bone loss modulated by the removal of weight-bearing from the skeleton is profoundly influenced by factors such as genetics, gender, and baseline morphology.

CONCLUSIONS

Adaptation of bone to functional challenges is complex but it is clear that more is not necessarily better and that even very low-magnitude mechanical signals can be anabolic. The development of effective biomechanical interventions in areas such as orthodontics, craniofacial repair, or osteoporosis will require the identification of the specific components of bone's mechanical environment that are anabolic, catabolic, or anti-catabolic.

Abnormally persistent latent inhibition induced by MK801 is reversed by risperidone and by positive modulators of NMDA receptor function: differential efficacy depending on the stage of the task at which they are administered

RATIONALE

Latent inhibition (LI) is the poorer conditioning to a stimulus resulting from its nonreinforced preexposure. LI indexes the ability to ignore irrelevant stimuli and is used extensively to model attentional impairments in schizophrenia (SZ). We showed that rats and mice treated with the N-methyl-D-aspartic acid (NMDA) receptor antagonist MK801 expressed LI under conditions preventing LI expression in controls. This abnormally persistent LI was reversed by the atypical antipsychotic drug (APD) clozapine and by compounds enhancing NMDA transmission via the glycineB site, but not by the typical APD haloperidol, lending the MK801 LI model predictive validity for negative/cognitive symptoms.

OBJECTIVE

To test additional representatives from the two classes of drugs and show that the model can dissociate between atypical APDs and glycinergic drugs are the objectives of the study.

MATERIALS AND METHODS

LI was measured in a conditional emotional response procedure. Atypical APD risperidone, selective 5HT2A antagonist M100907, and three glycinergic drugs were administered in preexposure or conditioning.

RESULTS

Rats treated with MK801 (0.05 mg/kg) exhibited LI under conditions that disrupted LI in controls. This abnormality was reversed by risperidone (0.25 and 0.067 mg/kg) and M100907 (1 mg/kg) given in preexposure. Glycine (0.8 g/kg), D-cycloserine (DCS;15 and 30 mg/kg), and glycyldodecylamide (GDA; 0.05 and 0.1 g/kg.) counteracted MK801-induced LI persistence when given in conditioning.

CONCLUSIONS

These results support the validity of MK801-induced persistent LI as a model of negative/cognitive symptoms in SZ and indicate that this model may have a unique capacity to discriminate between typical APDs, atypical APDs, and glycinergic compounds, and thus, foster the identification of novel treatments for SZ.

Exposure assessment of a mercury spill in a Nevada school -- 2004

BACKGROUND

Although mercury is toxic, few studies have measured exposure in children who handled elemental mercury briefly. In 2004, a student spilled approximately 60 milliliters of mercury at a Nevada school. Within 12 hours, all students were removed from the source of exposure. We conducted an exposure assessment at the school.

METHODS

We administered questionnaires and obtained urine samples from students. Using two-sample t-tests, we compared urine mercury levels from students who self-reported exposure to mercury levels of other students.

RESULTS

Two-hundred students participated, including 55/62 (89%) who were decontaminated. The students' geometric mean urine mercury level was 0.36 microg/L (95% confidence interval 0.32-0.40 microg/L). The student who brought the mercury to school was the only one to have an elevated urine mercury level (11.4 microg/L).

CONCLUSION

Despite environmental contamination, mercury exposure may have been minimized because of rapid identification of the elemental mercury spill and decontamination.

L’imagerie par résonance magnétique cérébrale fonctionnelle en pratique clinique

In the last decade, functional MRI (fMRI) has become one of the most widely used functional imaging technique in neurosciences. However, its clinical applications remain limited. Despite methodological and practical issues, fMRI data has been validated by different techniques (magnetoencephalography, Wada test, electrical and magnetic stimulations, and surgical resections). In neurosurgical practice, fMRI can identify eloquent areas involved in motor and language functions, and may evaluate characteristics of postoperative neurological deficit including its occurrence, clinical presentation and duration. This may help to inform patients and to prepare postoperative care. fMRI may also identify epileptic foci. In neurological practice, fMRI may help to determine prognosis of recovery after stroke, appropriate medication, and rehabilitation. fMRI may help to identify patients at risk of developing Alzheimer disease. Finally, cerebrovascular reactivity imaging is an interesting approach that might provide new radiological insights of vascular function.

Topoisomerase IIalpha in Wilms' tumour: gene alterations and immunoexpression

BACKGROUND

Topoisomerase IIalpha (topoIIalpha) is an essential enzyme gene in regulating DNA structure and cell proliferation and is encoded by the TOP2A. Using cDNA microarray analysis, TOP2A has been reported to be one of the top genes overexpressed in Wilms' tumour.

AIM

To evaluate the role of TopoIIalpha in Wilms' tumorigenesis and its prognostic value.

METHODS

TOP2A gene copy numbers were determined using the fluorescence in situ hybridisation technique, and protein expression levels of TopoIIalpha by immunostaining in 39 samples of primary and 18 samples of metastatic Wilms' tumour.

RESULTS

TOP2A gene amplification was detected only in anaplastic Wilms' tumours, and none of the Wilms' tumours showed deletion of the TOP2A gene. TopoIIalpha protein overexpression was detected in 97% of Wilms' tumours, and correlated strongly with proliferation, as measured by Ki-67 (r = 0.85). The high TopoIIalpha expression was associated with the presence of vascular invasion, prominent apoptosis, metastases and adverse clinical outcomes (p<0.05).

CONCLUSIONS

Our findings suggest that TopoIIalpha overexpression in Wilms' tumours is caused by a change at the transcription level, except for anaplastic Wilms' tumours, in which gene amplification was present. High levels of TopoIIalpha protein are correlated with tumour aggressiveness. The assessment of TopoIIalpha expression in Wilms' tumour may have prognostic value.

Functional age-dependent changes in bronchoalveolar lavage rat cells

Alveolar macrophages (AM) are located at the first line of non-specific defense against inhaled antigens in the lower respiratory tract and therefore represent the major effector cell in antimicrobial defense. Since children under 2 years are known to manifest increased susceptibility to lung infections we used a rat model to study functional capacities of the AM during different stages of development We analyzed several steps of the phagocytic process (adherence, chemotaxis and ingestion) as well as two different mechanisms of cytotoxicity [antibody dependent cellular cytotoxicity (ADCC) and cytotoxicity triggered by immune complex (ICC)] and tumor necrosis factor (TNF-alpha) secretion. We used young (4-6 weeks old), intermediate (16-25 weeks old) and adult (36-45 weeks old) rats. Adherence and phagocytic capacities of AM were lower in young rats compared to intermediate and adult animals. Chemotaxis towards the C5a complement component was low in the first two months of life, then it increased in the intermediate group and fell again in adults. Bronchoalveolar lavage (BAL) cells from young rats did not produce detectable TNF-alpha levels even when stimulated with phorbol 12-myristate 13-acetate (PMA). When we studied two different cytotoxic mechanisms we found that ICC markedly declines from youth to adulthood while ADCC showed a steady increase from youth to adulthood. In conclusion, our data show differences that may help to explain in part the enhanced susceptibility to pulmonary infections found in young children.

The UK national study of magnetic resonance imaging as a method of screening for breast cancer (MARIBS)

The UK national study of magnetic resonance imaging as a method of screening for breast cancer (MARIBS) is in progress. The study design, accrual to date, and related research projects are described. Revised accrual rates and expected recruitment are given. 15 cancers have been detected to date, from a total of 1236 screening measurements. This event rate and the tumour grades reported are compared with recent reports from other studies in women at high risk of breast cancer.

Skeletal adaptation to mechanical stimuli in the absence of formation or resorption of bone

Too often, unique loading environments fail to alter bone mass and morphology, calling to question the validity of Wolff's Law; the skeleton's plasticity to mechanical signals(1). We propose that bone can accommodate new loading environments without the need to form or resorb tissue, and that a critical aspect of bone tissue's ability to adapt to mechanical stimuli is first achieved via the plasticity of the osteocyte. We suggest that the osteocyte is capable of "normalizing" its local mechanical environment by modulating its cytoskeletal architecture, attachment to the matrix, configuration of the periosteocytic space, and communication channels to surrounding cells. We believe that through this local adaptive mechanism the osteocyte can accommodate the majority of changes in the mechanical milieu without altering the tissue architecture. It is only when bone tissue is subject to more severe (albeit rare) increases or decreases in the functional environment, the osteocyte participates in the formation and/or resorption of bone by coordinating site-specific recruitment of osteoblasts and/or osteoclasts. In vivo models of bone adaptation, combined with in situ reverse transcriptase-PCR, semi-quantitative RT-PCR, Northern analysis, immuno-cytochemistry and histomorphometry, can demonstrate how distinct mechanical stimuli influence the osteocyte's cytoskeletal and lacunar architecture, coupling (and uncoupling) of the osteocyte to the matrix and neighboring cells, and the osteocyte's participation in the recruitment and differentiation of osteoblasts and osteoclasts. Thus, the osteocyte controls three strategies to modulate its local and global environment in response to three distinct functional stimuli: 1) exogenous mechanical stimuli which are distinct from normal but sufficient to maintain bone mass, 2) mechanical stimuli which are osteogenic, and 3) disuse. If it is true that the resident cell population is capable of accommodating subtle changes in the functional milieu before modification of tissue morphology is deemed necessary, a novel strategy for the development of prophylaxes for osteopenia, osseointegration and fracture healing may become apparent.