Specific molecular peak analysis by ion mobility spectrometry of volatile organic compounds in urine of COVID-19 patients: A novel diagnostic approach

INTRODUCTION

SARS-CoV-2 is usually diagnosed from naso-/oropharyngeal swabs which are uncomfortable and prone to false results. This study investigated a novel diagnostic approach to Covid-19 measuring volatile organic compounds (VOC) from patients' urine.

METHODS

Between June 2020 and February 2021, 84 patients with positive RT-PCR for SARS-CoV-2 were recruited as well as 54 symptomatic individuals with negative RT-PCR. Midstream urine samples were obtained for VOC analysis using ion mobility spectrometry (IMS) which detects individual molecular components of a gas sample based on their size, configuration, and charge after ionization.

RESULTS

Peak analysis of the 84 Covid and 54 control samples showed good group separation. In total, 37 individual specific peaks were identified, 5 of which (P134, 198, 135, 75, 136) accounted for significant differences between groups, resulting in sensitivities of 89-94% and specificities of 82-94%. A decision tree was generated from the relevant peaks, leading to a combined sensitivity and specificity of 98% each.

DISCUSSION

VOC-based diagnosis can establish a reliable separation between urine samples of Covid-19 patients and negative controls. Molecular peaks which apparently are disease-specific were identified. IMS is an additional non-invasive and cheap device for the diagnosis of this ongoing endemic infection. Further studies are needed to validate sensitivity and specificity.

[Indications for nephron-sparing surgery. Analysis over a 13-year period in the context of changing guidelines]

BACKGROUND

The indications for nephron-sparing surgery have been considerably extended by guideline recommendations in recent years. It remains unclear whether clinical practice still reflects these new guidelines.

OBJECTIVE

In this retrospective, monocentric analysis at a tertiary referral center the indications for partial nephrectomy over a 13-year period were evaluated.

METHODS

In a retrospective database analysis all cases of surgically treated renal masses from 2001 to 2013 were evaluated. Besides demographic, tumor-specific and perioperative variables the development of the surgical technique depending on the tumor stage was evaluated.

RESULTS AND DISCUSSION

The proportion of nephron-sparing surgery cases increased from below 20 % in 2001 to 35 % in 2013 in the entire cohort. For stage T1a tumors, partial nephrectomy increased from approximately 50 % to over 90 % and for T1b tumors it rose from 10 % to 50 %. Logistic regression revealed stage 1 tumors to be predictive of partial nephrectomy over the complete evaluation period. Extending the indications for partial nephrectomy even to higher stages is under discussion but not yet supported by data from prospective, controlled studies.

Does visualisation during urethrocystoscopy provide pain relief? Results of an observational study

Background

To measure the effects of real-time visualisation during urethrocystoscopy on pain in patients who underwent ambulatory urethrocystoscopy.

Methods

An observational study was designed. From June 2012 to June 2013 patients who had ambulatory urethrocystoscopy participated in the study. In order to measure pain perception we used a numeric rating scale (NRS) 0 to 10. Additional data was collected including gender, reason for intervention, use of a rigid or a flexible instrument and whether the patient had had urethrocystoscopy before.

Results

185 patients were evaluated. 125 patients preferred to watch their urethrocystoscopy on a real-time video screen, 60 patients did not. There was no statistically relevant difference in pain perception between those patients who watched their urethrocystoscopy on a real-time video screen and those who did not (p = 0.063). However, men who were allowed to watch their flexible urethrocystoscopy experienced significantly less pain, than those who did not (p = 0.007). No such effects could be measured for rigid urethrocystoscopy (p = 0.317). Furthermore, women experienced significantly higher levels of pain during the urethrocystoscopy than men (p = 0.032).

Conclusions

Visualisation during urethrocystoscopy procedures in general does not significantly decrease pain in patients. Nevertheless, men who undergo flexible urethrocystoscopy should be offered to watch their procedure in real-time on a video screen. To make urethrocystoscopy less painful for both genders, especially for women, should be subject to further research.

[How can young academics be recruited? Acceptance and effects of urological practice-oriented training]

BACKGROUND

There is an increasing lack of young doctors in German hospitals, including urology departments. The aim of this study was to evaluate the benefit of urology practice-oriented courses for German students in a skills laboratory with respect to acceptance, learning success and enthusiasm of the students for urology.

METHODS

Transurethral catheterization, digital rectal examination and kidney/bladder sonography were trained in the urology course. Using a 12-point questionnaire, acceptance and quality of the training were evaluated. Learning success was checked using a urological OSCE-station (Objective Structured Clinical Examination). Additionally, participants were questioned on interest in urology and the consideration of future work in the field (medical elective or practical year).

RESULTS

A total of 147 questionnaires from 190 participating students were suitable for analysis. Acceptance and quality of training were highly ranked accompanied by a very satisfying objective and subjective learning success. Interest for urology was stimulated in 98.4 % and future work in urology was imaginable for 60.4 % of the students.

DISCUSSION

Practice-oriented urology student courses show high acceptance, high learning success and increase of attractiveness of urology. The training of urological skills represents a sufficient tool to entice students for urology and is helpful in enhancing the future of urology.

[Nonoperative management of rotator cuff defects]

Rotator cuff defects are common disorders of the shoulder. Although the outcome of surgical treatment of rotator cuff tears is well documented in the literature, less is known about the efficacy of physical therapy for symptomatic rotator cuff tears. Clear therapeutic standards are still missing. This article presents the nonoperative treatment options as well as a literature review. The results of most studies show that patients with rotator cuff defects do benefit from both physical therapy and simple home exercises independent from the size of the defect. However, due to the heterogeneity of outcome measures used, it is difficult to compare the results published. There is still a need for well-planned randomised controlled studies investigating the efficacy of exercise in the management of rotator cuff tears.

[Facial pain--dysfunction of the neck joints]

The etiopathogenesis of headache (cephalalgia) is multifactorial and has not been definitely clarified yet. One of the most frequent causes of this type of pain are disorders in the area of the neck joints such as locking of joints in passive or active movements or conditions affecting the segmentally arranged muscles. Manual mobilization of the affected joint structures or, possibly, a therapeutic nerve block is the most helpful treatment measure.