Genetic landscape of indolent and aggressive Kaposi sarcomas

BACKGROUND

Kaposi sarcoma (KS) is a rare skin tumour caused by herpesvirus 8 infection and characterized by either indolence or an aggressive course necessitating systemic therapies. The genetic basis of this difference remains unknown.

OBJECTIVES

To explore the tumour mutational burden in indolent and aggressive KS.

METHODS

We performed whole-exome sequencing on a cohort of 21 KS patients. We compared genetic landscape including tumor mutational burden between the two forms of indolent and agressive KS.

RESULTS

Aggressive KS tumours had a significantly higher TMB and a larger cumulative number of deleterious mutations than indolent KS tumours. In addition, all aggressive tumours had at least three deleterious mutations, whereas most indolent tumours harboured only one or no predicted deleterious mutations. Deleterious mutations listed in the Cancer Gene Census were detected exclusively in patients with aggressive disease. An analysis of somatic copy-number alterations (SCNA) revealed a tendency towards higher number of alterations in aggressive KS.

CONCLUSIONS

These data suggest that SCNA alterations and an increase in mutational burden promote aggressive KS and that it might be more appropriate to consider indolent KS as an opportunistic skin disease rather than a cancer.

Azithromycin resistance in Treponema pallidum in Reunion Island: A cross-sectional study

OBJECTIVE

Since the beginning of the 21st century, Reunion Island has experienced a syphilis epidemic. Infected patients are mostly heterosexual, with a high proportion of women, suggesting that congenital syphilis is present on the island. To determine whether azithromycin can be used for mass treatment of syphilis on Reunion Island, we assessed the prevalence of macrolide resistance in Treponema pallidum (TP).

METHODS

This monocentric cross-sectional study was conducted at the Reunion Island University Hospital. Samples were collected from lesions suggestive of primary or secondary syphilis. Samples positive for TP by multiplex polymerase chain reaction (PCR) were sent to the French National Reference Centre (NRC) for further analysis. Nested PCR-tpp47 was performed on these samples for detection of TP-DNA; 23s rRNA was amplified by PCR in confirmed positive samples. The Restriction Fragment Length Polymorphism (RFLP) technique was performed on samples with amplified 23s rRNA for detection of the A2058G mutation.

RESULTS

A total of 129 samples were collected from 119 patients. Of these, 18 tested positive for TP using multiplex PCR and were sent to the NRC. Fifteen (83.3%) of the 18 samples were confirmed positive by nested PCR-tpp47, and 23s rRNA was amplified in only 7 (38.9%) samples. Azithromycin resistance was detected in all TP strains with amplified 23s rRNA.

CONCLUSION

Amplification of 23s rRNA was successful in only 7 TP strains, all of which displayed resistance to macrolides. Keeping in mind the small sample size of our study, this suggests that azithromycin should not be used for mass treatment of syphilis in Reunion Island.

[A case of "early" syphilis]

INTRODUCTION

Syphilis mainly affects men who have sex with men (MSM) between the ages of 20 and 49. Herein we report a case in a teenager illustrating extension of the epidemic to other populations.

PATIENTS AND METHODS

A 15-year-old boy consulted in May 2018 for an anal fissure and painful oral erosions. He reported having had unprotected anal sex with another male teenager of the same age three months earlier. Syphilis serology was positive, with a positive treponemal test (TT) and non-treponemal test (VDRL) at 1/128. A treponemal bacterial DNA PCR assay was also positive for swabs obtained from the oral erosions and anal fissure. Due to a history of allergy to penicillin the patient was treated with doxycycline 200mg daily for 14 days. One month later, the mucosal lesions had subsided, and 3 months later the VDRL titer had decreased by 2 dilutions.

CONCLUSION

This case of "early" syphilis illustrates a change in the French epidemiology of sexually transmitted diseases (STIs). STIs currently affect very young and previously unexposed metropolitan French populations. These infections are increasing in teenagers due to an increase in high-risk sexual behavior associated with a lack of knowledge of STIs. This case is a reminder of the current decline in the level of knowledge about STIs among teenagers as compared to young people of the same age in the 1990s.

Report of High Temperature Measurements with a Fabry-Perot Extensometer

Fabry-Perot (FP) sensors like other Fiber Optic (FO) sensors may be of particular interest for in pile experiments in MTR with little room available thanks to their compact size. Light weight also reduces gamma heating hence limiting the thermal effect. Different physical parameters such as temperature, strain, displacement, vibration, pressure, or refractive index may be sensed through the measurement of the optical path length difference in the cavity. We have developed a Fabry-Perot extensometer able to operate at high temperature (up to 400°C), under a high level of radiation (neutron and gamma flux). The measurement based on interferometry is largely insensitive to radiation induced attenuation (RIA) thanks to the wavelength encoding of the useful signal, but for such high fluence as encountered in a reactor core, a special rad-hard fiber is needed. Operating in the wavelength domain around 1ím remains preferable to minimize the impact of irradiation. Moreover, fast neutron radiation is expected to change the structure of the fiber and possibly others materials in the transducer. Then, we revised the basic scheme of Extrinsic Fabry-Perot Interferometer (EFPI) so that the effects of compaction remain limited. Tests under mixed neutron and gamma irradiation permitted to verify the general behavior and particularly the low drift with radiation induced compaction (RIC). Also, two types of tests have been conducted to verify the accuracy at high temperature. The first ones are “measurements” of thermal dilatation of materials: the sensor is fixed on a sample and knowing its thermal expansion, it is possible to predict the measurement expected from the optical sensor when the temperature is increased from low to high temperature. The comparison between the predicted and experimental outputs informs on how the sensor is accurate. The second types are tests on a tensile test bench operating at high temperature. The Fabry-Perot measurements are compared, in the elastic domain, with the expected strain given by the Young modulus of the material, and also on a larger strain domain, with the measurements of a high temperature axial extensometer. Both types of tests are presented and commented.

Congenital syphilis: A prospective study of 22 cases diagnosed by PCR

Congenital syphilis (CS) is caused by Treponema pallidum infection in utero. There is a need to develop new tools to diagnose CS: the diagnostic value of PCR is difficult to assess. The aim of this study was to describe the clinical and laboratory characteristics of mothers and infants with CS as diagnosed by PCR tests on various maternal and neonatal samples.

PATIENTS AND METHODS

We included all infants epidemiologically linked to a mother diagnosed with syphilis whose samples were referred to the Syphilis Reference Center, and for whom at least one positive PCR result was obtained.

RESULTS

Twenty-two mother-infant pairs (8.3%) with assay performed on samples from one to four different anatomic sites were included between February 2011 and April 2018. Seven mothers (31.8%) were born abroad, fifteen (68.2%) presented psychological and/or social problems, eight (36.4%) had not been screened for syphilis prior to delivery, and eleven (50%) were referred from French overseas departments or territories, or from the Paris region. Six infants (27.3%) were stillborn and six were born preterm, while fifteen infants (68.2%) presented clinical features of CS. All infants born preterm were symptomatic. Infant VDRL/RPR titer was no greater than four times that in the mother's serum, except in two cases.

DISCUSSION

Lack of antenatal care, social disadvantage and psychological issues were common. There is a need for enhanced surveillance both in the French overseas departments/territories and in the Paris region. A larger study is required to assess the sensitivity and specificity of PCR. The best site for sampling has yet to be established. We recommend the collection of as many samples as possible to avoid underdiagnosis of CS.

Percutaneous hook wire assistance during laparoscopic excision of an intrarenal mass

Completely endophytic renal tumours pose challenges in laparoscopic nephron-sparing tumour excisions, with the use of intraoperative imaging techniques (e.g. ultrasound) being crucial when managing such tumours. The use of a percutaneous hookwire for tumour localisations are in use in several other surgical fields, such as breast surgery. An asymptomatic 52-year-old man presented with an incidental small right sided solid 33-mm interpolar renal mass identified on computed tomography. A guided insertion of a percutaneous localisation wire was carried out prior to a laparoscopic partial nephrectomy to assist in intraoperative tumour landmark/margins identification. Operative time was 210 minutes with zero ischaemia time, with an estimated blood loss of 200 ml. No perioperative complications were observed and the patient was discharged two days postoperatively. Histology revealed the mass to be a Fuhrman grade 2 clear-cell carcinoma with a 2-mm clear surgical margin. The patient remained free of recurrence at 16 months of follow-up. We have reported our first experience of wire localisation prior to laparoscopic partial nephrectomy for an intrarenal mass, which to our knowledge could be the first of its kind in renal surgery. Percutaneous wire localisation of endophytic renal tumours is potentially safe and effective and can allow nephron-sparing surgery where laparoscopic ultrasound is not available. Longer-term and further evidence should be encouraged.

Kidney cancer focal cryoablation trend: does location or approach matter?

PURPOSE

We evaluated the current indications and surgical and survival outcomes for cryoablation (CA) using either a percutaneous (PCA) or a laparoscopic approach (LCA). We also investigated the ability of the PADUA score to predict the risk of complications and local recurrence.

METHODS

A retrospective analysis was performed at two European tertiary referral centers. Parameters analyzed included size, location, approach, operative time, hospital stay, complications, and functional and oncologic outcomes. Univariate and multivariate analyses were performed. An ROC analysis was conducted to evaluate the accuracy of the PADUA score.

RESULTS

Eighty patients were included. Mean tumor size was 2.6 cm. PCA was more often performed in posterior (95 vs. 60 %), inferior (72 vs. 32 %), and lateral (87 vs. 55 %) tumors. The global complication rate was 8.75 %, although proximity to the renal sinus resulted in a higher rate (30 vs. 4 %). Mean follow-up was 34 and 23 months for LCA and PCA, respectively. The 5-year recurrence-free survival was 76 and 90 % for LCA and PCA, respectively. Multivariate analysis showed that tumor involvement of the collecting system was predictive of recurrence. Under ROC analysis, PADUA score was a mild predictor for complications (AUC = 0.601) and a good predictor for recurrence (AUC = 0.723); PADUA ≥8 was identified as a cutoff for patients to a higher risk of recurrence.

CONCLUSIONS

The percutaneous approach is confirmed to be the preferred CA technique for posterior and lateral tumors. CA in deeper renal lesions and tumors with PADUA score ≥8 might entail a higher risk of recurrence, and closer follow-up should be considered in these patients.

Fourier transform infrared spectroscopic study of surface acidity by pyridine adsorption on Mo/ZrO2-SiO2(Al2O3) catalysts

Acidity of the oxidic molybdenum catalysts supported on mixed ZrO2-SiO2 and ZrO2-Al2O3 carriers was investigated by Fourier transform infrared spectroscopy of pyridine adsorption. Deposition of molybdenum on ZrO2-SiO2 and ZrO2-Al2O3 supports leads to formation of surface Brønsted acid sites. The number of the Brønsted and Lewis acid sites in supported-molybdenum catalysts depends on both the ZrO2 content and the type of the support. With increasing ZrO2 content, the Lewis acid sites increase for both series of catalysts. The Brønsted acid sites are higher for Mo/ZrO2-SiO2 samples compared to those for Mo/ZrO2-Al2O3 and also increase with zirconia.