Interactions between free-living amoebae and Cryptosporidium parvum: an experimental study.

Free-Living Amebae (FLA) and Cryptosporidium oocysts occasionally share the same environment. From 2004 to 2016, Cryptosporidium was responsible for 60% of 905 worldwide waterborne outbreaks caused by protozoan parasites. The aim of this study was to evaluate interactions between C. parvum oocysts and two common FLAs (Acanthamoeba castellanii and Vermamoeba vermiformis) in a water environment. Encystment and survival of FLAs were evaluated by microscopy using trypan blue vital coloration. Oocysts were numerated on microscopy. Interactions were studied over time in conditions both unfavorable and favorable to phagocytosis. Potential phagocytosis was directly evaluated by several microscopic approaches and indirectly by numeration of microorganisms and oocyst infectivity evaluation. Occasional phagocytosis of C. parvum by FLAs was documented. However, oocyst concentrations did not decrease significantly, suggesting resistance of oocysts to phagocytosis. A temporary decrease of oocyst infectivity was observed in the presence of A. castellanii. The effect of these interactions on C. parvum infectivity is particularly interesting. The biofilm condition could favor the persistence or even the proliferation of oocysts over time. This study demonstrated interactions between C. parvum and FLAs. Further knowledge of the mechanisms involved in the decrease of oocyst infectivity in the presence of A. castellanii could facilitate the development of new therapeutic approaches.

Title: Interactions entre amibes libres et Cryptosporidium parvum : étude expérimentale. Abstract: Les amibes libres et les oocystes de Cryptosporidium partagent parfois le même environnement. Entre 2004 et 2016, Cryptosporidium a été responsable de 60 % des 905 épidémies d'origine hydrique dans le monde causées par des parasites protozoaires. Le but de cette étude était d'évaluer les interactions entre les oocystes de C. parvum et deux espèces d'amibes libres communes (Acanthamoeba castellanii et Vermamoeba vermiformis) en environnement aquatique. L'enkystement et la survie des amibes libres ont été évalués par microscopie en utilisant une coloration vitale au bleu trypan. Les oocystes ont été comptés au microscope. Les interactions ont été étudiées au cours du temps dans des conditions à la fois défavorables et favorables à la phagocytose. La phagocytose potentielle a été évaluée directement par plusieurs approches microscopiques et indirectement par la numération des micro-organismes et l'évaluation de l'infectiosité des oocystes. Une phagocytose occasionnelle de C. parvum par amibes libre a été documentée. Cependant, les concentrations d'oocystes n'ont pas diminué de manière significative, ce qui suggère une résistance des oocystes à la phagocytose. Une diminution temporaire de l'infectivité des oocystes a été observée en présence d'A. castellanii. L'effet de ces interactions sur l'infectiosité de C. parvum est particulièrement intéressant. La condition biofilm pourrait favoriser la persistance ou même la prolifération des oocystes de C. parvum au fil du temps. Cette étude a démontré des interactions entre C. parvum et amibes libres. Une meilleure connaissance des mécanismes impliqués dans la diminution de l'infectiosité des oocystes en présence d'A. castellanii pourrait faciliter le développement de nouvelles approches thérapeutiques.

Association of fetal heart rate short term variability pattern during term labor with neonatal morbidity and small for gestational age status.

OBJECTIVE: To assess the association of fetal heart rate short-term variability (STV) pattern during term labor with both neonatal composite morbidity (cord blood pH ≤ 7.10 and/or neonatal intensive care unit admission and/or Apgar score at 5 min <7) and small for gestational age (SGA) status. STUDY DESIGN: Retrospective cohort in a single academic institution between January 2016 and December 2018. A total of 1896 women that delivered a singleton during labor in cephalic presentation after 37 weeks of gestation were included (948 women with SGA neonates and 948 women with appropriate weight for gestational age (AGA) neonates that were matched to women with SGA neonates based on maternal age, parity, induction of labor, gestational diabetes, gestational age at delivery and a history of one cesarean section using propensity score matching). STV was compared at labor onset (cervical dilation ≤ 4 cm), in the first stage of labor (cervical dilation = 6 cm) and in the second stage of labor (cervical dilation = 10 cm). A generalized linear mixed model was used to assess the association between SGA status, neonatal composite morbidity and STV. RESULTS: After adjustment for maternal origin, term, gestational diabetes, labor length, SGA status was not associated with any change in STV during labor (mean adjusted STV: -0.20 ms, 95 %CI[-0.58-0.17], p = 0.284 at labor onset, 0.29 ms, 95 %CI[-0.1- 0.68], p = 0.155, in the first stage of labor and 0.36 ms, 95 %CI[-0.02-0.74], p = 0.065 in the second stage of labor). In case of neonatal composite morbidity mean adjusted STV was lower in the first stage of labor (mean adjusted STV: -1.29 ms, 95 %CI[-2.1 - -0.43], p = 0.003) and in the second stage of labor (mean adjusted STV: -1.15 ms, 95 %CI[-1.96 - -0.34], p = 0.005). The results were similar with the addition of delivery mode and meconium-stained amniotic fluid in the model or non-reassuring fetal heart rate and meconium-stained amniotic fluid. CONCLUSIONS: This work suggests that STV decrease during term labor is associated with fetal well-being, independently of fetal weight. This suggests that further prospective studies should consider the evaluation of this parameter in the prediction of neonatal compromise.

Management and prognosis of borderline ovarian Brenner tumors.

OBJECTIVE: The borderline ovarian Brenner tumor (BOBT) of the ovary is a rare tumor, and fewer than 25 cases have been reported in the literature. The aim of this study was to determine the prognosis of a series of BOBT collected in 2 reference centers. METHODS: A retrospective review of patients with BOBT treated or referred to our institutions. A centralized histological review by a reference pathologist and data on the clinical characteristics, management, and outcomes of patients were required for inclusion. RESULTS: Ten patients were identified between 2000 and 2010. The median age of patients was 69 years (range, 52-84 years). Eight patients had pure BOBT and 2 had mixed histotype (mucinous and Brenner tumor). All patients had unilateral tumor and a stage I disease. No case of stromal microinvasion or intraepithelial carcinoma was observed. Among 5 patients with data on the follow-up, 1 lethal recurrence (50 months after initial surgery) was observed (the first reported in the literature). CONCLUSIONS: During the management of BOBT, peritoneal staging surgery is not required because all patients reported in the present series (and all but one in the literature) had stage I disease. One recurrence had occurred in this retrospective series. Nevertheless, among 35 cases (including those in the present study) reported in the literature with outcomes, this tumor carries a good prognosis. The power of this conclusion is, however, limited because of the relatively small number of patients studied (but this is a rare entity) and the short follow-up period.

Management and prognosis of clear cell borderline ovarian tumor.

BACKGROUND: The clear cell borderline ovarian tumor (CCBOT) of the ovary is a rare tumor accounting for less than 1% of BOT. Fewer than 25 cases have been reported in the literature (including details on clinical management and outcomes). The aim of this study was to determine the prognosis of a series of CCBOTs collected in 2 reference centers. PATIENTS AND METHODS: This was a retrospective review of patients with CCBOT treated or referred to our institutions. A centralized histological review by a reference pathologist and data on the clinical characteristics, management, and outcomes of patients were required for inclusion. RESULTS: Twelve patients were identified between 2000 and 2010. The median age of patients was 68 years (range, 36-83 years). Two had been treated conservatively and 9 radically (data unknown in 1). The tumor was unilateral in 11 cases. All patients had stage I disease. All cases were CCBOT with an adenofibromatous pattern. Stromal microinvasion or intraepithelial carcinoma was histologically associated in 2 and 3 cases, respectively. Four of the 12 patients had synchronous endometrial disorders (but no endometrioid carcinoma). No cases were histologically associated with endometriosis. Four patients were lost to follow-up. Among 8 other patients, after a median period of 28 months (range, 2-129 months), no recurrence had occurred (1 patient had died of another disease). CONCLUSION: Clear cell borderline ovarian tumor carries a good prognosis. All tumors are stage I; therefore, surgical staging is not necessary in most of the cases. Conservative treatment could be proposed to young patients, but uterine curettage would then be required in cases of uterine preservation.