Perinatal Death: Epidemiology and Etiology

Perinatal mortality rate is an important mark to evaluate women and perinatal health care. It is of utmost importance to know causes and the evolution of its two components aiming to improve health care in different fields – sanitary conditions, diagnosis and treatment of infectious disease, immunisations, diagnosing and caring for medical diseases induced by pregnancy or directly related to it, providing skilled birth attendance, preventing birth asphyxia, preventing preterm birth complications and infections. In high-income countries the epidemiology varies mainly with social and economic conditions; in low-income countries, paired with poverty, undernutrition, superstition, lack of medical care, deficient basic sanitary conditions are also found. Also, in rich countries, responsible for 1% of deaths, data are published and improvements evaluated, while in low-income countries responsible for 99% of deaths numbers and causes are unknown, making difficult to implement cost effective interventions, a reason why “stillbirth rates in low-income countries are now where they were in high-income countries 50 to 100 years ago”. Knowledge on causes of death are very important as often what is needed are “simple” measures as improvement of sanitary conditions and immunisation programmes rather than high technologies. About four million babies dye each year in the first 28 days of life and another 3 million dye before birth in the third-trimester, with 98% occurring in low-income and middle income countries and more than 1 million occurring during labour and delivery. Classically stillbirths are the major component of perinatal mortality rate. Causes of death are even more difficult to know. In low-income countries a great proportion of women give birth at home. Worldwide the main causes of stillbirth are asphyxia due to obstructed labour, eclampsia, abruption placenta and umbilical cord complications - making valid the assumption that skilled birth attendance would decrease stillbirth; and infection - chorioamnioitis, syphilis and malaria. In high-income countries placental pathology and infection, congenital anomalies, complications of preterm birth and post term delivery, are the most common. If in low-income countries famine and lack of provisions and health care are common, in high-income countries, advanced maternal age and diabetes, obesity, hypertension, smoking, are frequent findings.

Colorimetric Assessment of BCR-ABL1 Transcripts in Clinical Samples Via Gold Nanoprobes

Gold nanoparticles functionalized with thiolated oligonucleotides (Au-nanoprobes) have been used in a range of applications for the detection of bioanalytes of interest, from ions to proteins and DNA targets. These detection strategies are based on the unique optical properties of gold nanoparticles, in particular, the intense color that is subject to modulation by modification of the medium dieletric. Au-nanoprobes have been applied for the detection and characterization of specific DNA sequences of interest, namely pathogens and disease biomarkers. Nevertheless, despite its relevance, only a few reports exist on the detection of RNA targets. Among these strategies, the colorimetric detection of DNA has been proven to work for several different targets in controlled samples but demonstration in real clinical bioanalysis has been elusive. Here, we used a colorimetric method based on Au-nanoprobes for the direct detection of the e14a2 BCR-ABL fusion transcript in myeloid leukemia patient samples without the need for retro-transcription. Au-nanoprobes directly assessed total RNA from 38 clinical samples, and results were validated against reverse transcription-nested polymerase chain reaction (RT-nested PCR) and reverse transcription-quantitative polymerase chain reaction (RT-qPCR). The colorimetric Au-nanoprobe assay is a simple yet reliable strategy to scrutinize myeloid leukemia patients at diagnosis and evaluate progression, with obvious advantages in terms of time and cost, particularly in low- to medium-income countries where molecular screening is not routinely feasible. Graphical abstract Gold nanoprobe for colorimetric detection of BCR-ABL1 fusion transcripts originating from the Philadelphia chromosome.