For avid glucose tumors, the SUV peak is the most reliable parameter for [(18)F]FDG-PET/CT quantification, regardless of acquisition time

Background

This study is an assessment of the impact of acquisition times on SUV with [¹⁸F]FDG-PET/CT on healthy livers (reference organ with stable uptake over time) and on tumors.

Methods

One hundred six [¹⁸F]FDG-PET/CT were acquired in list mode over a single-bed position (livers (n = 48) or on tumors (n = 58)). Six independent datasets of different durations were reconstructed (from 1.5 to 10 min). SUV_max (hottest voxel), SUV_peak (maximum average SUV within a 1-cm³ spherical volume), and SUV_average were measured within a 3-cm-diameter volume of interest (VOI) in the right lobe of the liver. For [¹⁸F]FDG avid tumors (SUV_max ≥ 5), the SUV_max, SUV_peak, and SUV_41% (isocontour threshold method) were computed.

Results

For tumors, SUV_peak values did not vary with acquisition time. SUV_max displayed significant differences between 1.5- and 5–10-min reconstruction times. SUV_41% was the most time-dependent parameter. For the liver, the SUV_average was the sole parameter that did not vary over time.

Conclusions

For [¹⁸F]FDG avid tumors, with short acquisition times, i.e., with new generations of PET systems, the SUV_peak may be more robust than the SUV_max. The SUV_average over a 3-cm-diameter VOI in the right lobe of the liver appears to be a good method for a robust and reproducible assessment of the hepatic metabolism.

Ancient DNA from Ascaris: extraction amplification and sequences from eggs collected in coprolites

On the Middle-Age site of Namur (Belgium) the analysis of coprolites revealed the presence of many well-preserved Ascaris eggs. Following rehydratation of the coprolite samples, 104 eggs were collected and extracted with an ultrasonication and phenol-chloroform based method. Three overlapping fragments of the 18S rRNA gene and one fragment of the cytochrome b gene have been reproducibly amplified, cloned and sequenced. The analysis of these sequences confirms the identification of the eggs as coming from Ascaris. Our study reveals that coprolites can be an interesting source of parasites that can be readily identified using molecular approaches. The study of ancient DNA from helminth parasites is of interest as it may answer long-standing questions in the history of infectious diseases and gives a possibility to compare these ancient sequences with those of modern populations.

Lipid nanocapsules loaded with rhenium-188 reduce tumor progression in a rat hepatocellular carcinoma model

BACKGROUND

Due to their nanometric scale (50 nm) along with their biomimetic properties, lipid nanocapsules loaded with Rhenium-188 (LNC(188)Re-SSS) constitute a promising radiopharmaceutical carrier for hepatocellular carcinoma treatment as its size may improve tumor penetration in comparison with microspheres devices. This study was conducted to confirm the feasibility and to assess the efficacy of internal radiation with LNC(188)Re-SSS in a chemically induced hepatocellular carcinoma rat model.

METHODOLOGY/PRINCIPAL FINDINGS

Animals were treated with an injection of LNC(188)Re-SSS (80 MBq or 120 MBq). The treated animals (80 MBq, n = 12; 120 MBq, n = 11) were compared with sham (n = 12), blank LNC (n = 7) and (188)Re-perrhenate (n = 4) animals. The evaluation criteria included rat survival, tumor volume assessment, and vascular endothelial growth factor quantification. Following treatment with LNC(188)Re-SSS (80 MBq) therapeutic efficiency was demonstrated by an increase in the median survival from 54 to 107% compared with control groups with up to 7 long-term survivors in the LNC(188)Re-SSS group. Decreased vascular endothelial growth factor expression in the treated rats could indicate alterations in the angiogenesis process.

CONCLUSIONS/SIGNIFICANCE

Overall, these results demonstrate that internal radiation with LNC(188)Re-SSS is a promising new strategy for hepatocellular carcinoma treatment.

Crab louse infestation in pre-Columbian America

Until now, Pthirus pubis infestation in ancient human populations had only been recorded in the Old World. We found crab lice on South American mummified bodies from the Atacama Desert region. Crab louse eggs were found attached to the pubic hairs of a 2,000-yr-old Chilean mummy. Well-preserved adults were found in sediment and clothing from a Peruvian mummy dated 1,000 yr ago. Paleoparasitological evidence expands the knowledge of the distribution of this ectoparasite in ancient populations. As with many other parasites, pubic lice recorded in Andean populations show the antiquity of this parasite in the New World. It is likely that P. pubis entered the continent with early human migration to the New World.

Identification of parasitoses in a child burial from Adak Island (Central Aleutian Islands, Alaska)

Bothriocephalid (Diphyllobothrium pacificum) and Ascarid (Ascaris lumbricoides) eggs have been identified in a sample taken in the abdominal cavity of a child skeleton found in Zeto Point (ADK-011), an archaeological site on Adak Island in the Central Aleutian Islands (Alaska).

Dioctophymidae eggs in coprolites from Neolithic site of Arbon-Bleiche 3 (Switzerland)

Dioctophymidae eggs were found in human coprolites dated from 3,384 to 3,370 BC from the site Arbon-Bleiche 3, Switzerland. This is the first record of dioctophymiasis in archaeological material. The important percentage of this disease in the studied coprolites raises the question of a higher prevalence during the Neolithic than at present.

Entropy maps characterize drug effects on brain dynamics in Alzheimer's disease

Non-linear quantifiers of brain electrical dynamics (entropy maps computed from the degradation of temporal forecasting of EEG signals) were studied in relation to drug treatment of Alzheimer's disease. A placebo condition was compared to three drug doses (50, 100 and 200 mg). A significant general effect of the drug was found when compared to placebo and specific contrasts between placebo and each of the three drug doses only reveal a significant entropy increase for the highest dose. These effects were localized bilaterally in fronto-temporal areas and support changes in the dynamics of the cerebral structures involved in memory processes.

Calibration test of PET scanners in a multi-centre clinical trial on breast cancer therapy monitoring using 18F-FLT

A multi-centre trial using PET requires the analysis of images acquired on different systems We designed a multi-centre trial to estimate the value of 18F-FLT-PET to predict response to neoadjuvant chemotherapy in patients with newly diagnosed breast cancer. A calibration check of each PET-CT and of its peripheral devices was performed to evaluate the reliability of the results.

Lésions mammaires impalpables et macrobiopsies stéréotaxiques avec le Mammotome® 11 G : faut-il opérer après diagnostic d’hyperplasie canalaire atypique ?

Atypical ductal hyperplasia (ADH) of the breast is a difficult histologic diagnosis. It is usually found, but not always, on clusters of microcalcifications. The subsequent risk of breast carcinoma is 4 to 5 times more important and the carcinoma can arise in the same breast or in the contralateral breast. Diagnosis can be establish on core needle biopsy with Mammotome 11G. The risk of under-estimation (ductal carcinoma in situ or invasive carcinoma) is about 20%. This risk is drastically decreased if the target (the calcifications) is completely removed by the Mammotome. This study includes 62 cases of ADH found on 633 calcifications biopsied by Mammotome 11G. In 31 cases, surgery was performed and ADH was confirmed in 25 cases (6 cases was under-estimated). In the other 31 cases, all calcifications were removed, there was no other risk factor and follow-up was suggested. Like after surgery, yearly bilateral mammography during about 20 years is recommended. In this last group, there was no false-negative result, median follow-up: 35,5 months (22-62).

Characterization of the distribution, retention, and efficacy of internal radiation of 188Re-lipid nanocapsules in an immunocompromised human glioblastoma model

Internal radiation strategies hold great promise for glioblastoma (GB) therapy. We previously developed a nanovectorized radiotherapy that consists of lipid nanocapsules loaded with a lipophilic complex of Rhenium-188 (LNC¹⁸⁸Re-SSS). This approach resulted in an 83 % cure rate in the 9L rat glioma model, showing great promise. The efficacy of LNC¹⁸⁸Re-SSS treatment was optimized through the induction of a T-cell immune response in this model, as it is highly immunogenic. However, this is not representative of the human situation where T-cell suppression is usually encountered in GB patients. Thus, in this study, we investigated the efficacy of LNC¹⁸⁸Re-SSS in a human GB model implanted in T-cell deficient nude mice. We also analyzed the distribution and tissue retention of LNC¹⁸⁸Re-SSS. We observed that intratumoral infusion of LNCs by CED led to their complete distribution throughout the tumor and peritumoral space without leakage into the contralateral hemisphere except when large volumes were used. Seventy percent of the ¹⁸⁸Re-SSS activity was present in the tumor region 24 h after LNC¹⁸⁸Re-SSS injection and no toxicity was observed in the healthy brain. Double fractionated internal radiotherapy with LNC¹⁸⁸Re-SSS triggered survival responses in the immunocompromised human GB model with a cure rate of 50 %, which was not observed with external radiotherapy. In conclusion, LNC¹⁸⁸Re-SSS can induce long-term survival in an immunosuppressive environment, highlighting its potential for GB therapy.

PRRSV detection by qPCR in processing fluids and serum samples collected in a positive stable breeding herd following mass vaccination of sows with a modified live vaccine

In the last two decades, in France, Porcine Reproductive and Respiratory Syndrome Virus (PRRSV) stabilization protocols have been implemented using mass vaccination with a modified live vaccine (MLV), herd closure and biosecurity measures. Efficient surveillance for PRRSV is essential for generating evidence of absence of viral replication and transmission in pigs. The use of processing fluid (PF) was first described in 2018 in the United States and was demonstrated to provide a higher herd-level sensitivity compared with blood samples (BS) for PRRSV monitoring. In the meantime, data on vertical transmission of MLV viruses are rare even as it is a major concern. Therefore, veterinarians usually wait for several weeks after a sow mass vaccination before starting a stability monitoring. This clinical study was conducted in a PRRSV-stable commercial 1000-sow breed-to-wean farm. This farm suffered from a PRRS outbreak in January 2018. After implementing a stabilisation protocol, this farm was controlled as stable for more than 9 months before the beginning of the study. PF and BS at weaning were collected in four consecutive batches born after a booster sow mass MLV vaccination. We failed to detect PRRSV by qPCR on PF and BS collected in a positive-stable breeding herd after vaccination with ReproCyc® PRRS EU (Boehringer Ingelheim, Ingelheim, Germany).

A starch-based microparticulate system dedicated to diagnostic and therapeutic nuclear medicine applications

The aim of this work was to develop a new microparticulate system able to form a complex with radionuclides with a high yield of purity for diagnostic or therapeutic applications. Owing to its properties potato starch was chosen as starting material and modified by oxidization and coupling of a ligand (polyamine) enabling modified starch to chelate radionuclides. The choice of suitable experiments was based on a combination of a Rechtschaffner experimental design and a surface response design to determine the influence of experimental parameters and to optimize the final product. Starch-based microparticle formulations from the experimental plans were compared and characterized through particle size analysis, scanning electron microscopy, elemental analysis and, for the most promising formulations, by in vitro labeling stability studies and determination of free polyamine content or in vivo imaging studies. The mechanism of starch-based microparticle degradation was identified by means of size measurements. The results of the Rechtschaffner design showed the positive qualitative effect of the temperature and the duration of coupling reaction whereas surface response analysis clearly showed that, by increasing the oxidization level and starch concentration, the nitrogen content in the final product is increased. In vitro and in vivo characterization led to identification of the best formulation. With a size around 30 μm, high radiochemical purity (over 95%) and a high signal-to-noise ratio (over 600), the new starch-based microparticulate system could be prepared as ready-to-use kits and sterilized without modification of its characteristics, and thus meet the requirement for in vivo diagnostic and therapeutic applications.

Ultrastructural changes following treatment with a microwave pulse in the oocyst of Eimeria magna Perard, 1925

The ultrastructure of oocysts of Eimeria magna was studied before and after their exposure to unique pulse of microwaves (2.450 MHZ; 600 W) of different durations (10, 15 and 20 s). Following treatment, the progressive destruction of the three layers of the oocyst wall was observed, the innermost being destroyed first. Internal structures were also affected, resulting in swollen mitochondria, a loss of ribosomes and fragmentation of the rough endoplasmic reticulum; moreover, the wall-forming bodies were no longer identifiable. Further studies using microwave pulses on biological material should be carried out to improve our understanding of the consequences of such treatment and to investigate its utility in the control of transmissible pathogenic organisms.

First recovery of Schistosoma mansoni eggs from a latrine in Europe (15-16th centuries)

Schistosoma mansoni eggs were found in a latrine dated AD 1450-1550 in Montbéliard, France. This is the first record of intestinal schistosomiasis in archaeological material. Because the parasite has an African origin, its presence in Europe at that time may be due to African slaves. However, intestinal schistosomiasis has never been established in Europe.

Ultrastructural studies of alterations induced by microwaves in Toxocara canis eggs: prophylactic interest

The ultrastructure of Toxocara canis eggs is described before and after exposure to microwaves. The morphology of normal eggs is compared to that of eggs from other helminths. Following treatment, the complete disorganization of the surface structure of the shell and the loss of much turgidity of the egg are observed. The destruction of the internal structure is most marked in the center of the egg and is associated with the disappearance of some layers of the shell. In addition, there is substantial damage to the synthesis apparatus (ribosomes, endoplasmic reticulum, lipid cisternae). An explanation based on the specific action of microwaves and micro-overheating is proposed, and the prophylactic use of this technique is considered.

Les opacités et les microcalcifications de la classification ACR 3 liées à un cancer

At screening mammography, lesions must be assigned to BI-RADS classification. Category 3 is used for nonpalpable probably benign lesions. This category is defined either by a subset of lesions that are so likely to be benign that follow-up is a reasonable alternative to immediate biopsy, or by a less than 2% malignancy rate for American BI-RADS, or than 5% for French ANAES. The initial work-up to analyze the lesion must be complete, not only with four screening standard views but with magnification views and sonography if necessary. The risk of malignancy is very low and the pronostic factors are the same as in screening detected carcinomas.