The impact of pronuclei morphology and dynamicity on live birth outcome after time-lapse culture.

STUDY QUESTION: Can the pronuclei (PN) morphology and the time of PN breakdown (PNB) predict the potential of embryos to result in live birth? SUMMARY ANSWER: In comparison to embryos resulting in no live birth, PNB occurred significantly later in embryos resulting in live birth and never earlier than 20 h 45 min. None of the tested scoring systems were shown to predict the live birth outcome in a time-lapse set-up. WHAT IS KNOWN ALREADY: The PN morphology is supported as a prominent embryo selection parameter in single light microscopy observations, although controversial results have been reported. STUDY DESIGN, SIZE, DURATION: This was a prospective study of 159 embryos, all of which were later transferred. The PN morphology of 46 embryos which resulted in live birth was compared with that of 113 embryos which resulted in no live birth. PARTICIPANTS, SETTING: From 1 March 2010 to 30 August 2011, 130 couples underwent fertility treatment by ICSI. Embryo culture was performed in a time-lapse set-up from fertilization to intrauterine transfer. PN morphological assessment was performed on every embryo replaced, using six different scoring systems at different times. MAIN RESULTS AND THE ROLE OF CHANCE: No embryo with PNB earlier than 20 h 45 min resulted in live birth. All six PN assessment models showed no significant distribution of scores (P = NS) between the live birth and no live birth groups at 16 h post-fertilization (PF), 18 h PF and 40 min before PNB. The outcomes of assessments changed significantly (P < 0.001) over time and the time of PNB was found to be the optimal stage to evaluate the PN morphology. LIMITATIONS, REASONS FOR CAUTION: The study includes only embryos reaching the 4-cell stage after ICSI, and transferred at 44 h PF. WIDER IMPLICATIONS OF THE FINDINGS: The PN morphology changes over time, indicating that the single light microscopy observation approach is deficient in comparison to time-lapse. Although the assessment of the PN morphology does not improve embryo selection, the timing of PNB should be included in embryo selection parameters.

Changes in the status of p53 affect drug sensitivity to thymidylate synthase (TS) inhibitors by altering TS levels.

Colorectal cancer (CRC) resistance to fluoropyrimidines and other inhibitors of thymidylate synthase (TS) is a serious clinical problem often associated with increased intracellular levels of TS. Since the tumour suppressor gene p53, which is mutated in 50% of CRC, regulates the expression of several genes, it may modulate TS activity, and changes in the status of p53 might be responsible for chemoresistance. Therefore, this study was aimed to investigate TS levels and sensitivity to TS inhibitors in wild-type (wt) and mutant (mt) p53 CRC cells, Lovo and WiDr, respectively, transfected with mt and wt p53. Lovo 175X2 cells (transfected with mt p53) were more resistant to 5-fluorouracil (5-FU; 2-fold), nolatrexed (3-fold), raltitrexed (3-fold) and pemetrexed (10-fold) in comparison with the wt p53 parental cells Lovo 92. Resistance was associated with an increase in TS protein expression and catalytic activity, which might be caused by the loss of the inhibitory effect on the activity of TS promoter or by the lack of TS mRNA degradation, as suggested by the reversal of TS expression to the levels of Lovo 92 cells by adding actinomycin. In contrast, Lovo li cells, characterized by functionally inactive p53, were 3-13-fold more sensitive to nolatrexed, raltitrexed and pemetrexed, and had a lower TS mRNA, protein expression and catalytic activity than Lovo 92. However, MDM-2 expression was significantly higher in Lovo li, while no significant differences were observed in Lovo 175X2 cells with respect to Lovo 92. Finally, mt p53 WiDr transfected with wt p53 were not significantly different from mt p53 WiDr cells with respect to sensitivity to TS inhibitors or TS levels. Altogether, these results indicate that changes in the status of p53, can differently alter sensitivity to TS inhibitors by affecting TS levels, depending on activity or cell line, and might explain the lack of clear correlation between mutations in p53 and clinical outcome after chemotherapy with TS inhibitors.

[Toxic shock syndrome due to Streptococcus pyogenes: a case report]. / Sindrome da shock tossico da Streptococco pyogenes: descrizione di un caso clinico e revisione della letteratura.

An increasing number of severe invasive Group A streptococcal infections have recently been reported. A new syndrome similar to the staphylococcal toxic shock syndrome, defined "streptococcal toxic shock-like syndrome" is also described. We report a case of streptococcal toxic shock-like syndrome with atypical clinical onset. A 67 years old man was admitted on the emergency department because of pain in the scapular area without fever. The patient developed irreversible shock and died after 36 hours. Diagnosis was made with autopsy. We stress the possibility of infectious cause in presence of severe multi organ failure with rapid clinical exacerbation.