Novel high-coverage primers for detection of canine morbillivirus by end-point and real-time RT-PCR assays

Canine distemper virus (CDV) is a major threat to domestic dogs and wildlife worldwide. Molecular assays are the most sensitive and specific tests to diagnose the disease, however, the high CDV genetic variability may compromise laboratory diagnosis. Herein, we designed a high-coverage primer set for end-point (RT-PCR) and real-time (RT-qPCR) for CDV detection. Initially, we collected 194 complete/near-complete CDV genomes (GenBank) and analyzed them for highly conserved regions for primer design. We then assessed the in silico coverage, analytical sensitivity, specificity and diagnostic performance of RT-PCR/RT-qPCR reactions based on our primers. Furthermore, the coverage of our primers, as well as their analytical sensitivity and diagnostic performance, were compared to a commonly used primer set for CDV detection (named PP-I). Our forward (F) and reverse (R) primers fully matched 100 % (194/194) and 99 % (192/194) of the analyzed sequences, whereas the PP-I F and R primers fully matched 15 % (29/194) and 9 % (18/194) sequences, respectively. The detection limit of our RT-PCR and RT-qPCR was equivalent to that of PP-I primers (0.001 TCID50/mL). Out of 70 clinical samples tested, 38 were positive by our RT-PCR/RT-qPCR assays, whereas reactions with primers PP-I failed to detect 9/28 (32 %) positive samples selected for comparison purposes. In addition, our assays did not amplify other canine viruses associated with respiratory and neurological diseases: canine adenovirus 2, canine parainfluenza virus 2, canine herpesvirus 1 and rabies virus. Overall, we describe a high-coverage primer set for CDV detection, which represents an attractive tool for laboratory diagnosis of canine distemper.

An end-point multiplex PCR/reverse transcription-PCR for detection of five agents of bovine neonatal diarrhea

Neonatal calf diarrhea (NCD) is frequently associated with single or mixed viral, bacterial and/or protozoal infections. Consequently, laboratory diagnostic of NCD usually requires specific tests for each potential agent; a time-consuming, laborious and expensive process. Herein, we describe an end-point multiplex PCR/reverse transcription-PCR (RT-PCR) for detection of five major NCD agents: bovine rotavirus (BRV), bovine coronavirus (BCoV), Escherichia coli K99 (E. coli K99), Salmonella enterica (S. enterica) and Cryptosporidium parvum (C. parvum). Initially, we selected and/or designed high-coverage primers. Subsequently, we optimized multiplex PCR/RT-PCR conditions. Next, we evaluated the analytical sensitivity of the assay and assessed the performance of the reaction by testing 95 clinical samples of diarrheic calf feces. The analytical specificity was evaluated against bovine viral diarrhea virus (BVDV), E. coli heat-stable enterotoxin (STa) and Eimeria spp. The detection limit of our assay was about 10 infectious units of BRV, 10^-2 dilution of a BCoV positive sample pool, about 5 × 10^-4 CFU for S. enterica, 5 × 10^-6 CFU for E. coli K99 and 50 oocysts for C. parvum. No non-specific amplification of other bovine diarrhea agents was detected. Out of 95 samples analyzed, 50 were positive for at least one target, being 35 single and 15 mixed infections. BRV was the most frequent agent detected in single infections (16/35), followed by Cryptosporidium spp. (11/35), which was the most frequent in mixed infections (11/15). Positive and negative multiplex results were confirmed in individual reactions. In conclusion, we described an end-point multiplex PCR/RT-PCR for faster and easier NCD diagnosis, which may be useful for routine diagnosis and surveillance studies.

An appraisal of gene targets for phylogenetic classification of canine distemper virus: Is the hemagglutinin the best candidate?

Sequence analysis of the canine distemper virus (CDV) hemagglutinin (H) gene may provide important insights on virus-host interactions and has also been frequently used for CDV phylogenetic classification. Herein, we performed an in silico analysis of CDV complete genomes (CGs) available in GenBank in order to investigate the suitability of H for CDV classification into lineages/genotypes. In addition, we analyzed the other viral genes for their potential use in CDV classification. Initially, we collected 116 CDV CGs from GenBank and compared their phylogenetic classification with that of their respective H nucleotide (nt) and amino acid (aa) sequences. Subsequently, we calculated the geodesic distance between the CG and H phylogenetic trees. These analyses were later performed with other CDV genes. All CDV CGs were also evaluated for possible recombination events. Nucleotide and aa analyses of H misclassified some Vaccine/America 1/Asia 3 lineage sequences compared to CG analysis, finding supported by both Maximum Likelihood (ML) and Bayesian Markov Chain Monte Carlo (B-MCMC) methods. Moreover, aa-based H analysis showed additional disagreements with the classification obtained by CG. The geodesic distance between the H and CG trees was 0.0680. Strong recombination signals were identified in the H gene, including Vaccine/America 1/Asia 3 lineage sequences. In contrast, C and P were the only genes that fully reproduced the CG classification (by ML and/or B-MCMC) and that did not show strong recombination signals. Furthermore, the P phylogenetic tree showed the lowest geodesic distance from the CG tree (0.0369). These findings suggest C and P as potential targets for CDV phylogenetic classification, especially when full genome sequencing is not possible. Finally, since our results were obtained considering the CDV CGs available to date, future analyses performed as more CDV sequences become available will be useful to assess probable issues of H-based phylogeny and to consolidate the suitability of the C and P genes for CDV classification.

End-to-side neurorrhaphy in peripheral nerves: Does it work?

Acute peripheral nerve injuries are common and can cause physical disabilities with sensory and functional sequelae; they therefore require surgery. The aim of this study was to conduct a systematic review to assess the clinical applicability of end-to-side neurorrhaphy in peripheral nerve reconstruction, based on available evidence. We carried out a systematic review of the literature using MEDLINE/PubMed, EMBASE, Cochrane Library, Web of Science, Scielo and Scopus through March 16, 2021. Most of the selected studies were qualitative and employed nonrandomized groups of patients, without standardized scales for assessing outcomes, which made statistical analysis difficult. Efficacy varied from 24% to 81%. Factors for better outcome included the type of injury, type of injured nerve (sensory, motor or mixed), presence of an epineural window, topography, injury extension <1.3 cm, and intervention within 2 weeks of injury. Clinical studies so far lack scientific evidence on end-to-side neurorrhaphy in peripheral nerve lesions.

P4724Elevated mitral valve pressure gradient is predictive for long-term outcome after percutaneous edge-to-edge mitral valve repair (PMVR) in patients with degenerative MR, but not in functional MR

Background

To analyze the effects of residual mitral regurgitation (MR) and mean mitral valve pressure gradient (MVPG) after percutaneous edge-to-edge mitral valve repair (PMVR) using the MitraClip-system on long term outcome.

Methods and results

Two hundred fifty-five patients who underwent PMVR were analyzed. Kaplan-Meier and Cox regression analyses were performed to evaluate the impact of residual MR and MVPG on clinical outcome. A combined clinical endpoint (all-cause mortality, MV surgery, redo procedure, implantation of a left ventricular assist device) was used.

After PMVR, mean MVPG increased from 1.6±1.0 mmHg to 3.1±1.5 mmHg (p<0.001). Reduction of MR severity to ≤2+ postintervention was achieved in 98.4% of all patients. In the overall patient cohort, residual MR was predictive for the combined endpoint while elevated MVPG >4.4 mmHg was not according to Kaplan-Meier and Cox regression analyses. We then analyzed the cohort with degenerative and that with functional MR separately to account for these different entities.In the cohort with degenerative MR, elevated MVPG was associated with increased occurrence of the primary endpoint, whereas this was not observed in the cohort with functional MR.

Conclusions

MVPG >4.4 mmHg after MitraClip-implantation was predictive for clinical outcome in the patient cohort with degenerative MR. In the patient cohort with functional MR, MVPG >4.4 mmHg was not associated with increased clinical events.

Acknowledgement/Funding

This study was supported by grants from the German Research Foundation (KFO 274), the Volkswagen Foundation (Lichtenberg Program) and the German Heart

Detection of tuberculosis patterns in digital photographs of chest X-ray images using Deep Learning: feasibility study

OBJECTIVE

To evaluate the feasibility of Deep Learning-based detection and classification of pathological patterns in a set of digital photographs of chest X-ray (CXR) images of tuberculosis (TB) patients.

MATERIALS AND METHODS

In this prospective, observational study, patients with previously diagnosed TB were enrolled. Photographs of their CXRs were taken using a consumer-grade digital still camera. The images were stratified by pathological patterns into classes: cavity, consolidation, effusion, interstitial changes, miliary pattern or normal examination. Image analysis was performed with commercially available Deep Learning software in two steps. Pathological areas were first localised; detected areas were then classified. Detection was assessed using receiver operating characteristics (ROC) analysis, and classification using a confusion matrix.

RESULTS

The study cohort was 138 patients with human immunodeficiency virus (HIV) and TB co-infection (median age 34 years, IQR 28-40); 54 patients were female. Localisation of pathological areas was excellent (area under the ROC curve 0.82). The software could perfectly distinguish pleural effusions from intraparenchymal changes. The most frequent misclassifications were consolidations as cavitations, and miliary patterns as interstitial patterns (and vice versa).

CONCLUSION

Deep Learning analysis of CXR photographs is a promising tool. Further efforts are needed to build larger, high-quality data sets to achieve better diagnostic performance.

Higher prevalence of joint hypermobility in constipation predominant irritable bowel syndrome

BACKGROUND

Joint hypermobility syndrome (JHS) is characterized by excessive connective tissue laxity manifest as joint hypermobility (JH) together with musculoskeletal symptoms. Previous studies have shown an association between JH/JHS and gastrointestinal symptoms, including irritable bowel syndrome (IBS), although its association with specific IBS subtypes is incompletely understood. We aimed to determine the prevalence of JH according to the subtypes of IBS, in particular IBS-C and IBS-D.

METHODS

Data of 228 consecutive IBS patients were analyzed. IBS was subtyped into constipation and diarrhea predominant IBS (IBS-C and IBS-D), IBS with mixed bowel habits (IBS-M) and unsubtyped IBS (IBS-U). JH was defined as a Beighton Score ≥4/9 points and JHS diagnosed according to revised Brighton Criteria. Data of IBS patients were analyzed for psychological comorbidities assessed by Hospital Anxiety and Depression Scale (HADS) and Visceral Sensitivity Index (VSI).

KEY RESULTS

Of 228 IBS patients, 64 (28.1%) suffered from IBS-C, 89 (39.0%) from IBS-D, 48 (21.1%) from IBS-M, and 27 (11.8%) from IBS-U. JH was diagnosed in 95 patients (41.7%). The prevalence of JH was significantly higher in IBS-C than IBS-D (57.8% vs 34.8%, P = .031). There was no significant difference in VSI and HADS according to JH or IBS subtype.

CONCLUSIONS AND INTERFERENCES

The prevalence of JH was significantly higher in IBS-C compared to IBS-D. Abnormalities in the connective tissue biomechanics in those with JH may contribute to a degree of colonic inertia which could result in constipation in JH-positive IBS patients. Further work is needed to determine the colonic biomechanics in patients with JH.

Water-fat Dixon sequences in the evaluation of breast implants: proposal of a time effective rapid approach in the clinical practice

AIM

To evaluate the diagnostic accuracy achieved from a fat-water Dixon sequence alone compared to a combination of a silicone-specific magnetic resonance imaging (MRI) sequence and a water-specific MRI sequence in the assessment of breast implants.

MATERIALS AND METHODS

In this institutional review board (IRB)-approved study the integrity of breast implants was assessed retrospectively in 27 patients undergoing breast MRI at 3 T. A qualitative evaluation of (set 1) a silicon-selective water-saturated short tau inversion recovery (STIR) sequence in combination with a water-only Dixon dataset (total acquisition time 7 minutes 17 seconds), and of (set 2) fat-only and water-only Dixon datasets (4 minutes 8 seconds) was performed by two readers independently evaluating the following features: margin definition of the implant, water suppression homogeneity, image quality, presence of artefacts and their effects on the imaging interpretation, and diagnostic confidence. Diagnostic accuracy in implant rupture detection was determined and either surgical confirmation or diagnosis from the radiological report was used as a standard of reference.

RESULTS

In both sequences, margin definition of the implant wall, water suppression homogeneity, and overall image quality were rated good-excellent in most of cases. Water suppression homogeneity was moderate-poor in a greater number of cases in set 1. Movement artefacts were more frequent in set 1 whereas five cases (18.5%) exhibited swap artefacts between silicone and water in set 2. Diagnostic confidence was rated high-very high with both sequences in most of cases. Diagnostic accuracy was 100% for both readers using set 1 and 96.2% and 100% using set 2.

CONCLUSION

A single Dixon sequence allows an accurate diagnostic evaluation of breast implants and concomitant shortening of the overall acquisition time.

Easy Pulsatile Phantom for Teaching and Validation of Flow Measurements in Ultrasound

PURPOSE

To build a simple model to teach and validate non-pulsatile and pulsatile flow quantification in ultrasound.

MATERIALS AND METHODS

The setting consists of the following connected components: (1) medical syringe pump producing an adjustable constant flow (ml/min), (2) modulator modifying constant flow to a reproducible pulsatile flow, (3) water tank containing a diagonal running silicone tube (0.5 mm inner diameter), and (4) a fixated ultrasound probe (L9 Linear Array 9 MHz, GE Logiq E9) measuring the flow inside the tube. Commercially available microbubbles suspended with physiological saline solution were used for ultrasonic visibility. Spectral Doppler of different flow profiles is performed.

RESULTS

The syringe pump produces an adjustable, constant flow and serves as the reference standard. The filling volume of the tube system is 1.2 ml. Microbubbles are very well detected by ultrasound and can be used as an easy and clean blood mimicking substance. The modulator generates different physiological and pathological flow profiles. Velocities are similar to those found within human blood vessels. Thus, it is possible to train and validate flow measurements in ultrasound.

CONCLUSION

The model produces non-pulsatile and various pulsatile flow profiles and allows validation of flow measurements. The compact size permits easy and economic setup for flow measurements in research, skills lab and continuing education.

Automatic radiation dose monitoring for CT of trauma patients with different protocols: feasibility and accuracy

AIM

To demonstrate the feasibility and accuracy of automatic radiation dose monitoring software for computed tomography (CT) of trauma patients in a clinical setting over time, and to evaluate the potential of radiation dose reduction using iterative reconstruction (IR).

MATERIALS AND METHODS

In a time period of 18 months, data from 378 consecutive thoraco-abdominal CT examinations of trauma patients were extracted using automatic radiation dose monitoring software, and patients were split into three cohorts: cohort 1, 64-section CT with filtered back projection, 200 mAs tube current-time product; cohort 2, 128-section CT with IR and identical imaging protocol; cohort 3, 128-section CT with IR, 150 mAs tube current-time product. Radiation dose parameters from the software were compared with the individual patient protocols. Image noise was measured and image quality was semi-quantitatively determined.

RESULTS

Automatic extraction of radiation dose metrics was feasible and accurate in all (100%) patients. All CT examinations were of diagnostic quality. There were no differences between cohorts 1 and 2 regarding volume CT dose index (CTDIvol; p=0.62), dose-length product (DLP), and effective dose (ED, both p=0.95), while noise was significantly lower (chest and abdomen, both -38%, p<0.017). Compared to cohort 1, CTDIvol, DLP, and ED in cohort 3 were significantly lower (all -25%, p<0.017), similar to the noise in the chest (-32%) and abdomen (-27%, both p<0.017). Compared to cohort 2, CTDIvol (-28%), DLP, and ED (both -26%) in cohort 3 was significantly lower (all, p<0.017), while noise in the chest (+9%) and abdomen (+18%) was significantly higher (all, p<0.017).

CONCLUSION

Automatic radiation dose monitoring software is feasible and accurate, and can be implemented in a clinical setting for evaluating the effects of lowering radiation doses of CT protocols over time.

Multiple intracranial meningiomas and cavernous hemangiomas

Intracerebral meningiomas and cavernous hemangiomas (hemangiomas, cavernomas) are entities frequently encountered by neuroradiologists and neurosurgeons. Even multiple tumors can often be observed in patients with certain congenital conditions, eg. multiple meningiomas in neurofibromatosis type 2 or multiple cavernous hemangiomas in familial cavernous malformations. However, there are only very few reported cases of concurrent meningiomas and cavernous hemangiomas, all but one related to prior radiotherapy. We describe the second case of concurrent multiple meningiomas and cavernous hemangiomas occurring de novo without a history of radiation.

Emotion, motivation, and text comprehension: the detection of contradictions in passages

The authors investigated the effects of experimentally induced mood states on the identification of contradictions in text passages and ratings of comprehension in 3 experiments. Mood impaired comprehension in college students across a variety of passages, as evidenced by a depressive impairment in contradiction identification and an increased number of false identifications among depressed participants. Additionally, depressed individuals were less accurate in their judgments of passage difficulty. These findings are consistent with the resource allocation model of mood effects, which attributes impaired comprehension to the activation of intrusive, irrelevant thoughts during reading of the passage. It is further argued that these results cannot be explained simply by a deficit in motivation of the depressed participants.

Emotion, motivation, and text comprehension: the detection of contradictions in passages

The authors investigated the effects of experimentally induced mood states on the identification of contradictions in text passages and ratings of comprehension in 3 experiments. Mood impaired comprehension in college students across a variety of passages, as evidenced by a depressive impairment in contradiction identification and an increased number of false identifications among depressed participants. Additionally, depressed individuals were less accurate in their judgments of passage difficulty. These findings are consistent with the resource allocation model of mood effects, which attributes impaired comprehension to the activation of intrusive, irrelevant thoughts during reading of the passage. It is further argued that these results cannot be explained simply by a deficit in motivation of the depressed participants.

Improvement in 'stat' laboratory turnaround time. A model continuous quality improvement project

BACKGROUND

Continuous quality improvement is being advocated as the process that, if adopted, would improve the efficiency, productiveness, and quality of medical institutions, thereby helping to solve the health care crisis our country is facing. To determine if these techniques could be effective in a tertiary-care multispecialty group practice, a model project was undertaken. The model project chosen was to determine if we could improve the turnaround time for "stat" laboratory examinations performed in our large outpatient facility.

METHODS

A 10-member team consisting of everyone involved in the process of laboratory testing was empowered to evaluate the present process and make appropriate changes. With traditional techniques of quality improvement, the process was assessed, data were collected and statistically analyzed, changes were introduced, and data were recollected and analyzed.

RESULTS

After intervention, the preanalytic delays were reduced by 76% and the postanalytic delays by 88%. Waiting time for patients was reduced by an average of 62%. By instituting the changes suggested, the institution saved $225,000 on a one-time basis and $40,000 to $50,000 on a recurring basis.

CONCLUSION

Adoption of quality improvement techniques appears to be a desirable management paradigm that should be explored by all medical institutions interested in maximizing the quality of care offered while at the same time minimizing its cost.