Publications by authors named "Zhaoxia Ren"

Developing timely, convenient, and low-cost methods for high-frequency characterization of soil nutrients is necessary for implementing precise soil nutrient management. With the current availability of numerous calibration models of laboratory benchtop near-infrared (NIR) spectrometers for rapid soil nutrient characterization and the appearance of low-cost, convenient miniaturized NIR spectrometers, this study proposes an efficient deployment strategy to address model failure due to inter-device variation based on spectral transfer. The strategy involves using Direct Standardization (DS) to migrate the spectra from multiple miniaturized NIR spectrometers with a laboratory benchtop NIR spectrometer and then directly applying the existing calibration models of the laboratory benchtop instrument to the transferred spectra for soil nutrient analysis.

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Pregnant and lactating women are considered "therapeutic orphans" because they generally have been excluded from clinical drug research and the drug development process owing to legal, ethical, and safety concerns. Most medications prescribed for pregnant and lactating women are used "off-label" because most of the clinical approved medications do not have appropriate drug labeling information for pregnant and lactating women. Medications that lack human safety data on use during pregnancy and lactation may pose potential risks for adverse effects in pregnant and lactating women as well as risks of teratogenic effects to their unborn and newborn babies.

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This study's primary objective was to fully characterize the pharmacokinetics of metformin in pregnant women with gestational diabetes mellitus (GDM) versus nonpregnant controls. Steady-state oral metformin pharmacokinetics in pregnant women with GDM receiving either metformin monotherapy ( = 24) or a combination with glyburide ( = 30) as well as in nonpregnant women with type 2 diabetes mellitus (T2DM) ( = 24) were determined utilizing noncompartmental techniques. Maternal and umbilical cord blood samples were collected at delivery from 38 women.

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Article Synopsis
  • * The results showed that while GLY reduced dynamic β-cell responsivity by 31%, both MET and COMBO significantly improved insulin sensitivity (SI) by 121% and 83%, respectively.
  • * Metformin resulted in a greater increase in the disposition index (DI) and a lower peak glucose concentration after meals compared to glyburide alone, suggesting that combining MET with GLY or insulin could provide a better approach to managing GDM than using just one medication
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Gestational diabetes mellitus is a condition similar to type 2 diabetes mellitus (T2DM) in that patients are unable to compensate for the degree of insulin resistance, and both conditions are often treated with metformin. The comparative pharmacodynamic response to metformin in these 2 populations has not been studied. This study characterized insulin sensitivity, β-cell responsivity, and disposition index following a mixed-meal tolerance test utilizing a minimal model of glucose, insulin, and C-peptide kinetics before and during treatment with metformin.

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Objective:  The objective of this study was to evaluate the impact of pregnancy history and 17-hydroxyprogesterone caproate (17-OHPC) treatment on cervical fluid cytokines and matrix metalloproteinases (MMPs).

Study Design:  Cervical fluid was obtained between 16 and 24 weeks from women with only prior term births (controls,  = 26), women with one or more prior spontaneous preterm births (SPTBs) choosing to receive 17-OHPC (17-OHPC,  = 24), or to not receive 17-OHPC (refusers,  = 12). Cervical fluid collections were repeated 2, 4, and 8 weeks after the first sample and concentrations of MMPs and cytokines were measured by multiplex immune assay.

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In April 2016, the Eunice Kennedy Shriver National Institute of Child Health and Human Development invited experts to a workshop to address numerous knowledge gaps and to review the evidence for the screening and management of opioid use in pregnancy and neonatal abstinence syndrome. The rising prevalence of opioid use in pregnancy has led to a concomitant dramatic fivefold increase in neonatal abstinence syndrome over the past decade. Experts from diverse disciplines addressed research gaps in the following areas: 1) optimal screening for opioid use in pregnancy; 2) complications of pregnancy associated with opioid use; 3) appropriate treatments for pregnant women with opioid use disorders; 4) the best approaches for detecting, treating, and managing newborns with neonatal abstinence syndrome; and 5) the long-term effects of prenatal opioid exposure on children.

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Background: Preeclampsia complicates approximately 3-5% of pregnancies and remains a major cause of maternal and neonatal morbidity and mortality. It shares pathogenic similarities with adult cardiovascular disease as well as many risk factors. Pravastatin, a hydrophilic, 3-hydroxy-3-methyl-glutaryl-coenzyme A reductase inhibitor, has been shown in preclinical studies to reverse various pathophysiological pathways associated with preeclampsia, providing biological plausibility for its use for preeclampsia prevention.

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Children have been called therapeutic orphans as they have been excluded from drug research and new drug development resulting in the lack of proper labels for majority of the drugs for pediatric use. The Best Pharmaceuticals for Children Act (BPCA) and the Pediatric Research Equity Act (PREA) are two legislative mandates to improve pediatric drug labeling. The BPCA legislation authorizes the National Institutes of Health (NIH) to implement research programs through funding clinical trials to study off-patent drugs in pediatric population.

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Aims: Physiological changes in pregnancy are expected to alter the pharmacokinetics of various drugs. The objective of this study was to evaluate systematically the pharmacokinetics of oseltamivir (OS), a drug used in the treatment of influenza during pregnancy.

Methods: A multicentre steady-state pharmacokinetic study of OS was performed in 35 non-pregnant and 29 pregnant women.

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To address provider struggles to provide evidence-based, rational drug therapy to pregnant women, this third Conference was convened to highlight the current progress and research in the field. Speakers from academic centers, industry, and governmental institutions spoke about: the Food and Drug Administration's role in pregnancy pharmacology and the new labeling initiative; drug registries in pregnancy; the pharmacist's role in medication use in pregnancy; therapeutic areas such as preterm labor, gestational diabetes, nausea and vomiting in pregnancy, and hypertension; breast-feeding and medications; ethical challenges for consent in pregnancy drug studies; the potential for cord blood banks; and concerns about the fetus when studying drugs in pregnancy. The Conference highlighted several areas of collaboration within the current Obstetrics Pharmacology Research Units Network and hoped to educate providers, researchers, and agencies with the common goal to improve the ability to safely and effectively use individualized pharmacotherapy in pregnancy.

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We sought to delineate the pharmacokinetics (PK) of oseltamivir and its active metabolite oseltamivir carboxylate during pregnancy. Physiologic changes of pregnancy, including increased renal filtration and secretion, may increase the clearance of oseltamivir carboxylate. Sixteen pregnant women taking oseltamivir for prophylaxis or treatment of suspected/proven influenza infection were enrolled.

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The United States is undertaking a major expansion of comparative effectiveness research, with the potential to achieve systemwide improvements in health care quality, outcomes, and resource allocation. However, to achieve these improvements in children's health and health care, comparative effectiveness research needs to be targeted, designed, conducted, and reported in ways that are responsive to the unique circumstances of children and adolescents. These include clinically important differences in the type and course of disease in children; demographic differences between the overall child and adult population in the United States, such as racial and ethnic makeup; and methodological issues involving study design.

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Gelatinous drop-like corneal dystrophy (GDLD) is a rare autosomal recessive disease characterized by the deposition of amyloid beneath the corneal epithelium and by severely impaired visual acuity leading to blindness. Although gelatinous corneal dystrophy has previously been mapped to chromosome 1p and seems to be associated with mutations in the M1S1 gene, molecular genetic studies have been limited to Japanese patients. To investigate the cause of GDLD in patients with diverse ethnic backgrounds, we performed linkage analyses in eight unrelated GDLD families from India, USA, Europe, and Tunisia.

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