Acute kidney injuries induced by thrombotic microangiopathy following severe hemorrhage in puerperants: a case series and literature review.

BACKGROUND: Acute kidney injury in puerperants is generally caused by acute tubular necrosis and occasionally by thrombotic microangiopathy (TMA) following post-partum hemorrhage. However, TMA leads to worse clinical outcomes and is rarely reported in the literature. Therefore, this study aimed to evaluate the pathological mechanism behind the development of TMA in puerperants to improve the diagnosis and treatment of this condition. METHODS: Three patients diagnosed with severe postpartum hemorrhage and TMA from 2014 to 2017 at a nephrology center were retrospectively investigated. RESULTS: All patients had severe hemorrhage during delivery with a mean blood loss, 4.0 L (range, 2.7-5.0 L). AKI developed rapidly in these patients and was treated with hemodialysis. Following treatment, the mean volume of packed red blood cells was 2.3 L (range, 1.2-3.6 L), and the mean volume of resuscitation fluid was 3.7 L (range, 3.5-4.0 L). All patients had renal biopsy specimens with typical TMA and ATN changes on light microscopy. Two patients required a hysterectomy while another two patients received respiratory support. Only one patient received plasma exchange. None of the patients had recovered normal kidney function by the final follow-up (26-61 months), with two patients having stage 3 chronic kidney disease, and one patient having an end-stage renal disease requiring maintenance hemodialysis. CONCLUSION: Severe postpartum hemorrhage could lead to TMA, in addition to the common finding of ATN. Renal histology revealed that poor renal outcomes could be attributed to TMA coexisting with ATN. The potential mechanism was ischemia-reperfusion, which was followed by endothelial cell injury and activation of the alternative complement pathway.

Medical nutrition therapy for pregnant women with gestational diabetes mellitus-A retrospective cohort study.

OBJECTIVE: Women diagnosed with gestational diabetes mellitus (GDM) remain at high risk of developing type 2 diabetes mellitus in the future. The effectiveness of medical nutrition therapy (MNT) acting on GDM is increasingly becoming noteworthy. MATERIALS AND METHODS: A retrospective cohort study involving 488 GDM cases was conducted. The prepregnancy weight, weight changes during pregnancy, glucose levels, GDM management, follow-up, and birth outcomes were recorded from 2008 to 2012. RESULTS: Overall, 62.91% of the women received MNT, with an increasing trend from 2008 to 2012 (p < 0.01). The fasting plasma glucose, 2-hour blood glucose, and weight gain at 28 weeks, 32 weeks, and 36 weeks as well as intrapartum were lower in the MNT group than in the non-MNT group. Total weight gain during pregnancy and the rates of adverse events during pregnancy were lower in the MNT group compared to the non-MNT group (all p < 0.05). Moreover, 92.2% of the participants in the MNT group had a normal oral glucose tolerance test result, and the rate of exclusive breastfeeding within 4 months after delivery was 54.4% in the MNT group; both were higher than those of the non-MNT group (66.3%, p < 0.001; 29.3%, p < 0.05). CONCLUSION: MNT can reduce the incidence of pregnancy complications, increase the exclusive breastfeeding rate, and improve pregnancy outcomes.

A Marked Increase in Obstetric Hysterectomy for Placenta Accreta.

BACKGROUND: Obstetric hysterectomy (OH) as a lifesaving measure to manage uncontrolled uterine hemorrhage appears to be increasing recently. The objective of this study was to determine the etiology and changing trends of OH and to identify those at particular risk of OH to enhance the early involvement of multidisciplinary intensive care. METHODS: A retrospective study was carried out in patients who had OH in China-Japan Friendship Hospital from 2004 to 2014. Maternal characteristics, preoperative evaluation, operative reports, and prenatal outcomes were studied in detail. RESULTS: There were 19 cases of OH among a total of 18,838 deliveries. Comparing the study periods between 2004-2010 and 2011-2014, OH increased from 0.8/1000 (10/12,890) to 1.5/1000 (9/5948). Indications for OH have changed significantly during this study period with uterine atony decreasing from 50.0% (5/10) to 11.1% (1/9) (P < 0.05), and placenta accreta as the indication for OH has increased significantly from 20.0% (2/10) to 77.8% (7/9) (P < 0.05). Ultrasonography and magnetic resonance imaging (MRI) have been used to make an exact antepartum diagnosis of placenta accreta. A multidisciplinary management led to improved outcomes for patients with placenta accreta. CONCLUSION: As the multiple cesarean delivery rates have risen, there has been a dramatic increase in OH for placenta accreta. An advance antenatal diagnosis of ultrasonography, and MRI, and a multidisciplinary teamwork can maximize patients' safety and outcome.

A classical but new kinetic equation for hydride transfer reactions.

A classical but new kinetic equation to estimate activation energies of various hydride transfer reactions was developed according to transition state theory using the Morse-type free energy curves of hydride donors to release a hydride anion and hydride acceptors to capture a hydride anion and by which the activation energies of 187 typical hydride self-exchange reactions and more than thirty thousand hydride cross transfer reactions in acetonitrile were safely estimated in this work. Since the development of the kinetic equation is only on the basis of the related chemical bond changes of the hydride transfer reactants, the kinetic equation should be also suitable for proton transfer reactions, hydrogen atom transfer reactions and all the other chemical reactions involved with breaking and formation of chemical bonds. One of the most important contributions of this work is to have achieved the perfect unity of the kinetic equation and thermodynamic equation for hydride transfer reactions.

Conversion and origin of normal and abnormal temperature dependences of kinetic isotope effect in hydride transfer reactions.

The effects of substituents on the temperature dependences of kinetic isotope effect (KIE) for the reactions of the hydride transfer from the substituted 5-methyl-6-phenyl-5,6-dihydrophenanthridine (G-PDH) to thioxanthylium (TX(+)) in acetonitrile were examined, and the results show that the temperature dependences of KIE for the hydride transfer reactions can be converted by adjusting the nature of the substituents in the molecule of the hydride donor. In general, electron-withdrawing groups can make the KIE to have normal temperature dependence, but electron-donating groups can make the KIE to have abnormal temperature dependence. Thermodynamic analysis on the possible pathways of the hydride transfer from G-PDH to TX(+) in acetonitrile suggests that the transfers of the hydride anion in the reactions are all carried out by the concerted one-step mechanism whether the substituent is an electron-withdrawing group or an electron-donating group. But the examination of Hammett-type free energy analysis on the hydride transfer reactions supports that the concerted one-step hydride transfer is not due to an elementary chemical reaction. The experimental values of KIE at different temperatures for the hydride transfer reactions were modeled by using a kinetic equation formed according to a multistage mechanism of the hydride transfer including a returnable charge-transfer complex as the reaction intermediate; the real mechanism of the hydride transfer and the root that why the temperature dependences of KIE can be converted as the nature of the substituents are changed were discovered.