Training in Skull Base Endonasal Endoscopic Surgery: Development and Validation of a Novel Low-Cost Simulation with Animal Cadaveric Model

BACKGROUND

Endoscopic skull base surgery is constantly evolving and its scope has expanded. The acquisition of surgical skills involves a long learning curve with significant risks for the patient. Therefore, training in the laboratory has become essential to achieve appropriate proficiency and reduce the morbidity and mortality associated with these procedures. The objective of our work is to develop and validate a cost-effective and easily replicable simulator for endonasal endoscopy training using a swine cadaveric model.

METHODS

We used fresh Pietrain swine heads. Training exercises of increasing complexity were performed. A Specific Technical Skills and Knowledge Scale was created considering the objectives to be assessed in each task. After the simulation, the trainees were required to answer a satisfaction survey.

RESULTS

Ten participants were recruited (5 neurosurgery residents and 5 neurosurgeons). The simulator assessment showed statistically significant differences between groups. Performance was better among the group with endoscopic surgery experience. Face validity was assessed through a postsimulation questionnaire showing an overall mean score of 28.7 out of 30, indicating a highly positive overall assessment of the simulator. Furthermore, 100% of the trainees believe that including endoscopy training in their education would be beneficial.

CONCLUSIONS

The endonasal endoscopy training simulator using a swine cadaveric model is a useful and accessible tool for enhancing surgical skills in this field. It provides an opportunity for training outside the operating room, reducing the potential risks associated with patient practice, and improving the training of residents.

Artificial intelligence solution to classify pulmonary nodules on CT

PURPOSE

The purpose of this study was to create an algorithm to detect and classify pulmonary nodules in two categories based on their volume greater than 100 mm³ or not, using machine learning and deep learning techniques.

MATERIALS AND METHOD

The dataset used to train the model was provided by the organization team of the SFR (French Radiological Society) Data Challenge 2019. An asynchronous and parallel 3-stages pipeline was developed to process all the data (a data "pre-processing" stage; a "nodule detection" stage; a "classifier" stage). Lung segmentation was achieved using 3D U-NET algorithm; nodule detection was done using 3D Retina-UNET and classifier stage with a support vector machine algorithm on selected features. Performances were assessed using area under receiver operating characteristics curve (AUROC).

RESULTS

The pipeline showed good performance for pathological nodule detection and patient diagnosis. With the preparation dataset, an AUROC of 0.9058 (95% confidence interval [CI]: 0.8746-0.9362) was obtained, 87% yielding accuracy (95% CI: 84.83%-91.03%) for the "nodule detection" stage, corresponding to 86% specificity (95% CI: 82%-92%) and 89% sensitivity (95% CI: 84.83%-91.03%).

CONCLUSION

A fully functional pipeline using 3D U-NET, 3D Retina-UNET and classifier stage with a support vector machine algorithm was developed, resulting in high capabilities for pulmonary nodule classification.

Genotypic and Phenotypic Characterization of Streptomyces Species Causing Potato Common Scab in Uruguay

Isolation and characterization of common scab (CS) pathogen Streptomyces spp. from Uruguayan potato tubers and soil samples were done in response to significant economic losses due to CS on potato in autumn 2010. Seventy of the 331 isolates were classified as pathogenic owing to their ability to induce necrosis on tuber disks and stunting of radish seedling. Streptomyces spp. causing CS on potato in Uruguay were found to represent a range of different species by virtue of their diverse morphological and physiological traits as well as rep-PCR, rpoB phylogenetic analysis, and multi-locus sequences analysis. We identified isolates primarily as Streptomyces scabiei, S. acidiscabies, and S. europaeiscabiei. However, some of the pathogenic isolates still remain to be identified at the species level. This highlights the need for improved methods for discrimination among pathogenic Streptomyces species. The presence of Streptomyces pathogenicity island (PAI) genes was analyzed, including genes encoding for thaxtomin synthetase (txtA, txtB), tomatinase (tomA), and a necrosis protein (nec1). Among the isolates that were pathogenic, 50% contained the four pathogenicity genes, 33% had an atypical composition of PAI marker genes, and 17% did not contain any genes. The absence of the genes reported to be involved in thaxtomin biosynthesis (txtA, txtB) was confirmed by whole-genome sequencing of two representative strains of this group. This finding suggests the participation of other virulence factors in plant pathogenicity.

[Open versus laparoscopic radical prostatectomy: a French center experience]

OBJECTIVE

To compare peri-operative outcomes of open radical prostatectomy (ORP) to laparoscopic radical prostatectomy (LRP) in a single French institution.

METHODS

Between 1998 and 2003, 72 patients underwent ORP followed by 279 LRP between 2003 and 2010 for a clinically localized prostate cancer. Demographic, peri-operative and pathological data in the ORP and LRP groups were analyzed and compared.

RESULTS

In the ORP group, compared to the LRP group, the following significant differences were found: patients were older (63.1 years versus 65.6), initial PSA was higher (10.2 ng/mL versus 6.7) and the proportion of T1c was higher (62.8 % versus 80.6 %). Operative blood loss (1500 mL versus 500) and length of hospitalization (9.0 days versus 6.3) were higher in the ORP group (P<0.001). Operative time was longer in the LRP group (250 min versus 160; P<0 .001). There was no significant difference regarding length of catheterization (average of 8.5 days). Anastomotic strictures were more frequent following ORP (P<0.001). Positive margins proportion in the ORP group (7.1 %) was lower than that observed in the LRP group (28.7 %) (P=0.001). Patients in the ORP group achieved early continence more frequently (P<0.01) but at 12 months postoperatively there was no significant difference.

CONCLUSION

Patients in the LRP group had lower operative blood losses and a shorter length of hospitalization. However, in the ORP group, operative time was shorter and positive margins rate was lower.

First Report Regarding Potato Scab Caused by Streptomyces acidiscabies in Uruguay

Potato scab disease is caused by gram-positive filamentous bacteria in the genus Streptomyces. A great variety of species cause this disease, but Streptomyces scabies is the most ancient of these pathogens and can be found in a worldwide distribution, whereas S. turgidiscabies and S. acidiscabies are newly emerged pathogens (2). During the autumn of 2010, potato (Solanum tuberosum) crops had large economic losses by common scab, corresponding to 29% of the total potato-cultivation area (according to our survey), which was unusual in Uruguay. Specifically, the disease was very aggressive and the tubers showed particularly deep scab lesions. We isolated the Streptomyces species present in these particular scab lesions of tubers collected in July 2010 from one of the three potato cultivation areas (San José). A total of 19 Streptomyces spp. strains were isolated and identified using classical and molecular techniques. Morphological characteristics of colonies and microscopic structure of the mycelium were observed (1). Molecular characterization by conventional PCR was carried out using primers directed to specific regions of the 16S rRNA gene for the genus Streptomyces, Aci1: (5'-TCACTCCTGCCTGCATGGGCG-3') and Aci2: (5'-CGACAGCTCCCTCCCACAAG-3'). Also, regions of two pathogenicity genes, namely txtAB and nec1, were amplified and confirmed by sequencing (2). Additionally, melanin production and pathogenicity of the isolates was determined by inoculation of potato discs (1). Six of the 19 strains succeeded in PCR amplification with primers specific to Streptomyces acidiscabies, which has white, aerial hypha and flexuous spore chains. These strains did not produce melanin on tyrosine agar media. The amplified fragments for 16S rRNA and pathogenicity genes from one representative strain 61 were sequenced. BLASTn analysis of the 16S rRNA gene sequence obtained of the strain 61 (Accession No. JN206667) showed the highest similarity (100%) with S. acidiscabies type strain 84-01-182 (GenBank Accession No. FJ007427.1). Pathogenicity of the isolate was tested on tuber slices. The isolate was grown on YME for 5 to 7 days at 28°C and agar plugs from the sporulating colonies were inverted onto excised tuber tissue. Disks were incubated at 28°C in the dark and the presence of necrosis was evaluated after 5 days (1). All tuber slice assays were repeated three times. The noninoculated control tuber slices did not show any necrosis, while those inoculated with the strain did. To our knowledge, this is the first report of S. acidiscabies causing potato scab disease in Uruguay. References: (1) D. H. Park et al. Plant Dis. 87:1290, 2003. (2) L. A. Wanner. Phytopathology 96:1361, 2006.

[Lymphangiosarcoma treated with liposomal doxorubicin (Caelyx)]

BACKGROUND

Lymphangiosarcoma is a highly malignant tumor with a poor prognosis. Anthracyclines constitute the form of chemotherapy most commonly used in these patients. Unfortunately, they are poorly tolerated. We report a case of lymphangiosarcoma in an elderly woman with good response to liposomal doxorubicin, an anthracycline with lower toxicity.

CASE REPORT

A 70 year-old-woman with a previous history of post-mastectomy lymphedema presented a painful and bleeding lymphangiosarcoma on the arm and the chest. Because of the wide extent of the tumor, surgery was not performed. The patient was treated with liposomal doxorubicin 50 mg/m2. Marked tumor regression was observed after the first course of chemotherapy. After 5 courses, 90% regression of tumor mass was seen. Pain and bleeding also stopped. Two months after the final course of liposomal doxorubicin, relapse occurred and the patient died.

DISCUSSION

A dramatic response to liposomal doxorubicin was noted in the present case, as previously reported in a patient with an angiosarcoma of the scalp. Liposomal doxorubicin could be considered for the treatment of lymphangiosarcoma, particularly in elderly patients.

Complications liées à l’exérèse du ganglion sentinelle dans le mélanome

INTRODUCTION

Side-effects occurring after sentinel lymph node excision in malignant melanoma patients have been poorly evaluated to date. The aim of the present study was to assess the side-effects of sentinel lymph node excision in this population.

PATIENTS AND METHODS

All consecutive malignant melanoma patients undergoing sentinel lymph node excision between March 2000 and December 2002 were included in this retrospective study. Patients with a metastatic sentinel node subsequently undergoing lymph node dissection were excluded. Median follow-up of patients was 12.6 +/- 8.8 months. Complications were classified as "early" (i.e. occurring the month following surgery), or "late" (after this time).

RESULTS

Forty malignant melanoma patients (17 males, 23 females) with a normal histologic examination of their sentinel lymph node were included. They belonged to a series of sixty-one melanoma patients undergoing lymph node excision. Fourteen complications were observed in ten patients. Two early complications were seen: hematoma (n=1) and deep venous thrombosis with pulmonary embolism (n=1). Twelve late complications were observed: mild lymphoedema (n=5), hypertrophic scars (n=2), painful scars (n=4), and one chronic seroma (n=1). Many complications (33%) were observed after excision in the inguinal area.

DISCUSSION

The complications of sentinel lymph node excision must be considered in determining the benefit/risk ratio of this technique.

The extent to which breakfast covers the morning energy expenditure of adolescents with varying levels of physical activity

BACKGROUND

Energy intake at breakfast affects the performance of creativity tests, memory recall and voluntary physical endurance in children before lunch, and food craving during the whole day.

OBJECTIVES

To assess the adequacy of breakfast energy supply (BES) and energy expenditure (EE) in adolescents during a schoolday without or with 2 h of physical education lesson (PEL) in the morning.

DESIGN

Sixty adolescents (four groups of 14-16 boys and girls aged 12-16 y) participated in a cross-sectional study. Activity patterns and EE were determined by whole-body calorimetry during 36 h and in free-living conditions during 5 days using both a diary and the validated heart rate recording method. BES was determined by weighing individual foods. The pyloric energy flow was assessed using a model of fractional stomach emptying.

RESULTS

BES averaged 24.9% (s.d.=6.1) of daily EE in the four groups of subjects. It covered the mean morning EE on a schoolday without PEL, but not in a schoolday with 2 h of PEL in any group. When PEL took place from 8-10 am the cumulative EE exceeded the cumulative pyloric energy flow after 105-150 min, that is during the PEL session, and the energy deficit increased until lunch. With a light breakfast (BES-1 s.d.) energy deficiency happened after 90 min.

CONCLUSION

The results stress the need for a heavy breakfast for children and adolescents on the days with PEL in the morning, and a carbohydrate rich snack at 10 am to improve attention, memory and willing participation in physical activities.

Protein feeding pattern does not affect protein retention in young women

This study was undertaken to determine whether a pulse protein feeding pattern was more efficient than a spread pattern to improve protein anabolism in young women as was already shown in elderly women. After a 15-d adaptive period [1.2 g protein/(kg fat-free mass. d)], 16 young women (age 26 +/- 1 y) were given a 14-d diet providing 1.7 g protein/(kg fat-free mass. d), using either a pulse pattern (protein consumed mainly in one meal, n = 8), or a spread pattern (spreading daily protein intake over four meals, n = 8). Nitrogen balance was determined at the end of both the 15-d adaptive and the 14-d experimental periods. Whole-body protein turnover was determined at the end of the 14-d experimental period using [(15)N]glycine as an oral tracer. Nitrogen balance was 17 +/- 5 mg N/(kg fat-free mass. d) during the adaptive period. It was higher during the experimental period, but not significantly different in the women fed the spread or the pulse patterns [59 +/- 12 and 36 +/- 8 mg N/(kg fat-free mass. d) respectively]. No significant effects of the protein feeding pattern were detected on either whole-body protein turnover [5.5 +/- 0.2 vs. 6.1 +/- 0.3 g protein/(kg fat-free mass. d) for spread and pulse pattern, respectively] or whole-body protein synthesis and protein breakdown. Thus, in young women, these protein feeding patterns did not have significantly different effects on protein retention.

Protein pulse feeding improves protein retention in elderly women

BACKGROUND

Adequate protein nutrition could be used to limit gradual body protein loss and improve protein anabolism in the elderly.

OBJECTIVE

We tested the hypothesis that an uneven protein feeding pattern was more efficient in improving protein anabolism than was an even pattern.

DESIGN

After a controlled period, 15 elderly women (mean age: 68 y) were fed for 14 d either a pulse diet (n = 7), providing 80% of the daily protein intake at 1200, or a spread diet (n = 8), in which the same daily protein intake was spread over 4 meals. Both diets provided 1.7 g protein x kg fat-free mass (FFM)(-1) x d(-1). Protein accretion and daily protein turnover were determined by using the nitrogen balance method and the end product method (ammonia and urea) after an oral dose of [15N]glycine.

RESULTS

Nitrogen balance was more positive with the pulse than with the spread diet (54 +/- 7 compared with 27 +/- 6 mg N x kg FFM(-1) x d(-1); P < 0.05). Protein turnover rates were also higher with the pulse than with the spread diet (5.58 +/- 0.22 compared with 4.98 +/- 0.17 g protein x kg FFM(-1) x d(-1); P < 0.05), mainly because of higher protein synthesis in the pulse group (4.48 +/- 0.19 g protein x kg FFM(-1) x d(-1)) than in the spread group (3.75 +/- 0.19 g protein x kg FFM(-1) x d(-1)) (P < 0.05).

CONCLUSION

A protein pulse-feeding pattern was more efficient than was a protein spread-feeding pattern in improving, after 14 d, whole-body protein retention in elderly women.

Net energy value of non-starch polysaccharide isolates (sugarbeet fibre and commercial inulin) and their impact on nutrient digestive utilization in healthy human subjects

The energy value of NSP has been expressed as their metabolizable energy (ME) content. The aim of the present study was to determine whether differences in ME and net energy (NE) contents were similar for insoluble and soluble NSP. Nine healthy young men were offered three diets according to a Latin-square design (3 x 3) with three repetitions: diet C (control), diet B (control + 50 g sugarbeet fibre/d) and diet I (control + 50 g commercial inulin/d). After a 16 d adaptation period to NSP isolate, food intake was controlled (duplicate meal method) and faeces and urine were collected for 8 d. A period of 60 h was devoted to measurement of energy expenditure (EE) by whole-body indirect calorimetry. NSP-isolate ingestion induced significant increases in the number of defecations and stool weight resulting from increases in water, DM and microbial mass excretion. After deduction of microbial N, differences in faecal N excretion between diets were not significantly different. Urinary N excretion was slightly decreased by sugarbeet fibre or commercial inulin ingestion but the N balances for the diets were not significantly different. Diet energy, N and lipid apparent digestibilities decreased by only 1-2%. Commercial inulin was entirely fermented and fermentability of sugarbeet fibre averaged 0.886 (SD 0.117). Sugarbeet fibre and commercial inulin ME values averaged 10.7 (SD 1.2) and 13.0 (SD 2.3) kJ/g DM respectively. NSP-isolate ingestion caused significant (sugarbeet) and nonsignificant (inulin) increases in daily EE. The maintenance NE contents of sugarbeet fibre and inulin averaged 5.0 (SD 5.0) and 11.9 (SD 1.3) kJ/g DM respectively. Differences in maintenance NE contents of NSP isolates were much greater than differences in ME values.

Oxidative stress status and antioxidant status are apparently not related to carotenoid status in healthy subjects

Several lines of evidence suggest that carotenoids may have a beneficial effect on health as a result of their antioxidant properties. In addition to beta-carotene, five other carotenoids are recovered in noticeable amounts from human plasma and tissues. Although the effect of beta-carotene on in vivo lipid peroxidation has been documented, few data are available on the effects of the other carotenoids. We evaluated the ability of the main human carotenoids to reduce lipid peroxidation by determining the correlations between plasma carotenoid concentration and plasma antioxidant capacity (in 79 healthy volunteers) and between carotenoid status and breath pentane excretion (in a subgroup of 24 subjects). Carotenoid intake was assessed by means of a 3-day food recall. Carotenoid status was evaluated by measurement of beta-carotene, lycopene, lutein/zeaxanthin, and alpha-carotene in plasma and buccal mucosal cells. Antioxidant status was evaluated by measurement of the total antioxidant capacity of the plasma. Oxidative stress status was evaluated by breath pentane measurements. Food recall data and the carotenoid concentrations in plasma and buccal mucosal cells showed that the subjects had normal carotenoid intake and normal carotenoid status. The total antioxidant capacity of the plasma was not related to the concentration of any specific carotenoid. The level of expired air pentane was not related to the carotenoid status of the subjects. These results show that normal concentrations of carotenoids in plasma and tissues are not correlated with these clinical markers of antioxidant and oxidative stress status.

Critical evaluation of the factorial and heart-rate recording methods for the determination of energy expenditure of free-living elderly people

The aim of the present study was to validate against the doubly-labelled water (DLW) technique the factorial method and the heart rate (HR) recording method for determining daily energy expenditure (DEE) of elderly people in free-living conditions. The two methods were first calibrated and validated in twelve healthy subjects (six males and six females; 70.1 (SD 2.7) years) from open-circuit whole-body indirect calorimetry measurements during three consecutive days and during 1 d respectively. Mean energy costs of the various usual activities were determined for each subject using the factorial method, and individual relationships were set up between HR and energy expenditure for the HR recording method. In free-living conditions, DEE was determined over the same period of time by the DLW, the factorial and the HR recording methods during 17, 14 and 4 d respectively. Mean free-living DEE values for men estimated using the DLW, the factorial and the HR recording methods were 12.8 (SD 3.1), 12.7 (SD 2.2) and 13.5 (SD 2.7) MJ/d respectively. Mean free-living DEE values for women were 9.6 (SD 0.8), 8.8 (SD 1.2) and 10.2 (SD 1.5) MJ/d respectively. No significant differences were found between the three methods for either sex, using the Bland & Altman (1986) test. Mean differences in DEE of men were -0.9 (SD 11.8) % between the factorial and DLW methods, and + 4.7 (SD 16.1) % between the HR recording and DLW methods. Similarly, in women, mean differences were -7.7 (SD 12.7) % between the factorial and DLW methods, and + 5.9 (SD 8.8) % between the HR recording and DLW methods. It was concluded that the factorial and the HR recording methods are satisfactory alternatives to the DLW method when considering the mean DEE of a group of subjects. Furthermore, mean energy costs of activities calculated in the present study using the factorial method were shown to be suitable for determining free-living DEE of elderly people when the reference value (i.e. sleeping metabolic rate) is accurately measured.

Gender differences in energy expended during activities and in daily energy expenditure of elderly people

Gender effects on energy expended during light seated activities, walking, cycling, and sleep and their consequences on daily energy expenditure (EE) were examined in 11 men and 15 women aged 66.4 +/- 7.1 yr. Two open-circuit whole body calorimeters were used for EE measurements, except for cycling, during which EE was measured separately with the use of a face mask. Lean body mass (determined using H218O dilution method), fat mass, usual physical activity level, and activity intensity (e.g., walking speed and cycling power output) were taken as covariates in the analysis of EE variations before studying gender effects. Sleeping metabolic rate (SMR) and daily EE, adjusted for differences in all covariates, were 11.2 (P = 0.005) and 8.7% (P = 0.071) lower in women than in men, respectively. No gender-related differences were found in the various physical activity EEs above SMR (e.g., gross EE-SMR) [light seated activities (P = 0.790), walking (P = 0.263), and cycling (P = 0.287)] and daily physical activity EE above SMR (P = 0.587) after adjustment for differences in all covariates. Therefore, the lower adjusted daily EE of women could be related to their lower SMR, the most reliable criterion of whole body metabolic rate.